https://hades.mech.northwestern.edu//index.php?action=history&feed=atom&title=Linear_Amplifier_Motor_Driver 2026-05-18T05:23:33Z Revision history for this page on the wiki MediaWiki 1.43.8 https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=3971&oldid=prev 2006-10-20T23:44:34Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:44, 20 October 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 4:</td> <td colspan="2" class="diff-lineno">Line 4:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control analog voltage. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control voltage. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control analog voltage. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control voltage. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A <del style="font-weight: bold; text-decoration: none;">better</del> <del style="font-weight: bold; text-decoration: none;">linear amplifier, and the associated</del> board<del style="font-weight: bold; text-decoration: none;"> available</del> for<del style="font-weight: bold; text-decoration: none;"> stuffing in the NU mechatronics lab, is described</del> [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm <del style="font-weight: bold; text-decoration: none;">here</del>]. With <del style="font-weight: bold; text-decoration: none;">that</del> circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A <ins style="font-weight: bold; text-decoration: none;">printed</ins> <ins style="font-weight: bold; text-decoration: none;">circuit</ins> board for [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm <ins style="font-weight: bold; text-decoration: none;">a better linear amplifier</ins>]<ins style="font-weight: bold; text-decoration: none;"> is available for stuffing in the NU mechatronics lab</ins>. With <ins style="font-weight: bold; text-decoration: none;">this</ins> circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>While linear amplifiers can work very well, they are not very power efficient. Lots of power can be dumped into heat when the transistors are not saturated, as the power dissipated as heat by a transistor is equal to the voltage from the collector to the emitter multiplied by the current flowing through it. As a result, large heatsinks may be required for the transistors even when using small motors. For a more power-efficient method of driving motors, which also has the benefit that only on-off voltages are required, consult [[Pulse Width Modulation]]. In this control mode, the driving transistors are nearly always saturated, meaning little power dissipated as heat by the transistors.</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>While linear amplifiers can work very well, they are not very power efficient. Lots of power can be dumped into heat when the transistors are not saturated, as the power dissipated as heat by a transistor is equal to the voltage from the collector to the emitter multiplied by the current flowing through it. As a result, large heatsinks may be required for the transistors even when using small motors. For a more power-efficient method of driving motors, which also has the benefit that only on-off voltages are required, consult [[Pulse Width Modulation]]. In this control mode, the driving transistors are nearly always saturated, meaning little power dissipated as heat by the transistors.</div></td> </tr> </table>

Lynch https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=3970&oldid=prev 2006-10-20T23:41:51Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:41, 20 October 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a linear "push-pull" current amplifier. The op-amp</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a linear "push-pull" current amplifier. The op-amp</div></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control analog voltage. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control <del style="font-weight: bold; text-decoration: none;">input</del>. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control analog voltage. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control <ins style="font-weight: bold; text-decoration: none;">voltage</ins>. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> </tr> </table>

Lynch https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=3969&oldid=prev 2006-10-20T23:41:03Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:41, 20 October 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a linear "push-pull" current amplifier. The op-amp</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a linear "push-pull" current amplifier. The op-amp</div></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control <del style="font-weight: bold; text-decoration: none;">signal</del>. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control input. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control <ins style="font-weight: bold; text-decoration: none;">analog voltage</ins>. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control input. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> </tr> </table>

Lynch https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=3968&oldid=prev 2006-10-20T23:40:27Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:40, 20 October 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker"><a class="mw-diff-movedpara-right" title="Paragraph was moved. Click to jump to old location." href="#movedpara_2_1_lhs">&#x26AB;</a></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><a name="movedpara_0_0_rhs"></a>[[image:linear amplifier schematic.jpg|500px]]</div></td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a linear "push-pull" current amplifier. The op-amp</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a linear "push-pull" current amplifier. The op-amp</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control signal. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control input. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control signal. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control input. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><br /></td> <td colspan="2" class="diff-empty diff-side-added"></td> </tr> <tr> <td class="diff-marker"><a class="mw-diff-movedpara-left" title="Paragraph was moved. Click to jump to new location." href="#movedpara_0_0_rhs">&#x26AB;</a></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><a name="movedpara_2_1_lhs"></a>[[image:linear amplifier schematic.jpg|500px]]</div></td> <td colspan="2" class="diff-empty diff-side-added"></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can choose whether to have the voltage across the motor, or the current through the motor, be proportional to the analog input voltage.</div></td> </tr> </table>

Lynch https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=3967&oldid=prev 2006-10-20T23:40:02Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:40, 20 October 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a "push-pull" current amplifier<del style="font-weight: bold; text-decoration: none;">. This circuit uses two transistors to "push" or "pull" current through the motor. The transistors are npn-type and are activated by an applied voltage</del>. The op-amp<del style="font-weight: bold; text-decoration: none;"> linearizes the circuit and provides a current gain. The input is an analog voltage.</del></div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a<ins style="font-weight: bold; text-decoration: none;"> linear</ins> "push-pull" current amplifier. The op-amp</div></td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>provides high input impedance, so it draws little current from the input control signal. The op-amp also works to keep the voltage at its inverting input (the - terminal) equal to the control voltage at the noninverting input (+ terminal). In other words, the voltage across the motor should be equal to the control input. The op-amp cannot provide enough current to drive the motor, so we use transistors to boost the current. The "top" transistor is an npn transistor (e.g., a TIP31), and it "pushes" current through the motor (current travels left to right) when the control voltage is positive. The "bottom" transistor is a pnp transistor (e.g., a TIP32), and it "pulls" current through the motor (current travels right to left) when the control voltage is negative. </div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can <del style="font-weight: bold; text-decoration: none;">decide</del> whether <del style="font-weight: bold; text-decoration: none;">it</del> <del style="font-weight: bold; text-decoration: none;">is</del> the voltage across the motor, or the current through the motor, <del style="font-weight: bold; text-decoration: none;">that is</del> proportional to the analog input voltage.</div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. With that circuit, you can <ins style="font-weight: bold; text-decoration: none;">choose</ins> whether <ins style="font-weight: bold; text-decoration: none;">to</ins> <ins style="font-weight: bold; text-decoration: none;">have</ins> the voltage across the motor, or the current through the motor, <ins style="font-weight: bold; text-decoration: none;">be</ins> proportional to the analog input voltage.</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>While linear amplifiers can work very well, they are not very power efficient. Lots of power can be dumped into heat when the transistors are not saturated, as the power dissipated as heat by a transistor is equal to the voltage from the collector to the emitter multiplied by the current flowing through it. As a result, large heatsinks may be required for the transistors even when using small motors. For a more power-efficient method of driving motors, which also has the benefit that only on-off voltages are required, consult [[Pulse Width Modulation]]. In this control mode, the driving transistors are nearly always saturated, meaning little power dissipated as heat by the transistors.</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>While linear amplifiers can work very well, they are not very power efficient. Lots of power can be dumped into heat when the transistors are not saturated, as the power dissipated as heat by a transistor is equal to the voltage from the collector to the emitter multiplied by the current flowing through it. As a result, large heatsinks may be required for the transistors even when using small motors. For a more power-efficient method of driving motors, which also has the benefit that only on-off voltages are required, consult [[Pulse Width Modulation]]. In this control mode, the driving transistors are nearly always saturated, meaning little power dissipated as heat by the transistors.</div></td> </tr> </table>

Lynch https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=3966&oldid=prev 2006-10-20T23:28:50Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:28, 20 October 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. </div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier<ins style="font-weight: bold; text-decoration: none;">. It provides a voltage across the motor equal to the voltage at the noninverting input of the op amp</ins>. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. <ins style="font-weight: bold; text-decoration: none;">With that circuit, you can decide whether it is the voltage across the motor, or the current through the motor, that is proportional to the analog input voltage.</ins></div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>While<del style="font-weight: bold; text-decoration: none;"> a</del> linear <del style="font-weight: bold; text-decoration: none;">amplifier</del> can work very well, they are not very power efficient. Lots of power <del style="font-weight: bold; text-decoration: none;">is</del> dumped into heat. <del style="font-weight: bold; text-decoration: none;">Large</del> heatsinks may be required for the transistors even when using small motors. For a more power-efficient method of driving motors, which also has the benefit that only on-off voltages are required, consult [[Pulse Width Modulation]].</div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>While linear <ins style="font-weight: bold; text-decoration: none;">amplifiers</ins> can work very well, they are not very power efficient. Lots of power <ins style="font-weight: bold; text-decoration: none;">can be</ins> dumped into heat<ins style="font-weight: bold; text-decoration: none;"> when the transistors are not saturated, as the power dissipated as heat by a transistor is equal to the voltage from the collector to the emitter multiplied by the current flowing through it</ins>. <ins style="font-weight: bold; text-decoration: none;">As a result, large</ins> heatsinks may be required for the transistors even when using small motors. For a more power-efficient method of driving motors, which also has the benefit that only on-off voltages are required, consult [[Pulse Width Modulation]]<ins style="font-weight: bold; text-decoration: none;">. In this control mode, the driving transistors are nearly always saturated, meaning little power dissipated as heat by the transistors</ins>.</div></td> </tr> </table>

Lynch https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=3961&oldid=prev 2006-10-20T23:20:34Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 18:20, 20 October 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>This is a very simple linear amplifier. A better linear amplifier, and the associated board available for stuffing in the NU mechatronics lab, is described [http://www.mech.northwestern.edu/courses/433/Writeups/MotorAmp/motoramp.htm here]. </div></td> </tr> <tr> <td class="diff-marker"><a class="mw-diff-movedpara-left" title="Paragraph was moved. Click to jump to new location." href="#movedpara_3_1_rhs">&#x26AB;</a></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><a name="movedpara_2_0_lhs"></a><del style="font-weight: bold; text-decoration: none;">One</del> <del style="font-weight: bold; text-decoration: none;">of</del> <del style="font-weight: bold; text-decoration: none;">the</del> <del style="font-weight: bold; text-decoration: none;">problems</del> <del style="font-weight: bold; text-decoration: none;">with</del> <del style="font-weight: bold; text-decoration: none;">this</del> <del style="font-weight: bold; text-decoration: none;">circuit</del> <del style="font-weight: bold; text-decoration: none;">is</del> <del style="font-weight: bold; text-decoration: none;">that</del> <del style="font-weight: bold; text-decoration: none;">it</del> <del style="font-weight: bold; text-decoration: none;">isn't</del> very efficient. Lots of power is dumped<del style="font-weight: bold; text-decoration: none;"> into ground and</del> into heat. Large heatsinks <del style="font-weight: bold; text-decoration: none;">are</del> required for the transistors even when using small motors. For a more efficient method, consult [[Pulse Width Modulation]].</div></td> <td colspan="2" class="diff-empty diff-side-added"></td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker"><a class="mw-diff-movedpara-right" title="Paragraph was moved. Click to jump to old location." href="#movedpara_2_0_lhs">&#x26AB;</a></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><a name="movedpara_3_1_rhs"></a><ins style="font-weight: bold; text-decoration: none;">While</ins> <ins style="font-weight: bold; text-decoration: none;">a</ins> <ins style="font-weight: bold; text-decoration: none;">linear</ins> <ins style="font-weight: bold; text-decoration: none;">amplifier</ins> <ins style="font-weight: bold; text-decoration: none;">can</ins> <ins style="font-weight: bold; text-decoration: none;">work</ins> <ins style="font-weight: bold; text-decoration: none;">very</ins> <ins style="font-weight: bold; text-decoration: none;">well,</ins> <ins style="font-weight: bold; text-decoration: none;">they</ins> <ins style="font-weight: bold; text-decoration: none;">are</ins> <ins style="font-weight: bold; text-decoration: none;">not</ins> very<ins style="font-weight: bold; text-decoration: none;"> power</ins> efficient. Lots of power is dumped into heat. Large heatsinks <ins style="font-weight: bold; text-decoration: none;">may be</ins> required for the transistors even when using small motors. For a more <ins style="font-weight: bold; text-decoration: none;">power-</ins>efficient method<ins style="font-weight: bold; text-decoration: none;"> of driving motors, which also has the benefit that only on-off voltages are required</ins>, consult [[Pulse Width Modulation]].</div></td> </tr> </table>

Lynch https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=2618&oldid=prev 2006-06-27T16:35:01Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 11:35, 27 June 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 3:</td> <td colspan="2" class="diff-lineno">Line 3:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>One of the problems with this circuit is that it isn't very efficient. Lots of power is dumped into ground and into heat. Large heatsinks are required for the transistors even when using small motors.</div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>One of the problems with this circuit is that it isn't very efficient. Lots of power is dumped into ground and into heat. Large heatsinks are required for the transistors even when using small motors<ins style="font-weight: bold; text-decoration: none;">. For a more efficient method, consult [[Pulse Width Modulation]]</ins>.</div></td> </tr> </table>

Stephens https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=2617&oldid=prev 2006-06-27T16:32:08Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 11:32, 27 June 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 2:</td> <td colspan="2" class="diff-lineno">Line 2:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg|500px]]</div></td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td colspan="2" class="diff-empty diff-side-deleted"></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>One of the problems with this circuit is that it isn't very efficient. Lots of power is dumped into ground and into heat. Large heatsinks are required for the transistors even when using small motors.</div></td> </tr> </table>

Stephens https://hades.mech.northwestern.edu//index.php?title=Linear_Amplifier_Motor_Driver&diff=2615&oldid=prev 2006-06-27T16:30:08Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 11:30, 27 June 2006</td> </tr><tr> <td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a "push-pull" current amplifier. This circuit uses two transistors to "push" or "pull" current through the motor. The transistors are npn-type and are activated by an applied voltage. The op-amp linearizes the circuit and provides a current gain. The input is an analog voltage.</div></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A simple driver for a motor is a "push-pull" current amplifier. This circuit uses two transistors to "push" or "pull" current through the motor. The transistors are npn-type and are activated by an applied voltage. The op-amp linearizes the circuit and provides a current gain. The input is an analog voltage.</div></td> </tr> <tr> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> <td class="diff-marker"></td> <td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br /></td> </tr> <tr> <td class="diff-marker" data-marker="−"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg]]</div></td> <td class="diff-marker" data-marker="+"></td> <td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[image:linear amplifier schematic.jpg<ins style="font-weight: bold; text-decoration: none;">|500px</ins>]]</div></td> </tr> </table>

Stephens