Limit Switch - Revision history

Stephens at 19:09, 10 August 2006

2006-08-10T19:09:15Z

← Older revision		Revision as of 14:09, 10 August 2006
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	<h4>Switch Debouncing</h4>		<h4>Switch Debouncing</h4>

	<P>Most switches are mechanical and vibrate when switched from one position to another. To learn about this and how to counteract it see the section on [[Schmitt Triggers]]</P>		<P>Most switches are mechanical and vibrate when switched from one position to another. To learn about this and how to counteract it see the section on [[Schmitt Trigger\|Schmitt Triggers]]</P>

	<h4>Connecting a switch to the PC/104 Stack</h4>		<h4>Connecting a switch to the PC/104 Stack</h4>

Stephens at 20:04, 13 June 2006

2006-06-13T20:04:38Z

← Older revision		Revision as of 15:04, 13 June 2006
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	<P>Most switches are mechanical and vibrate when switched from one position to another. To learn about this and how to counteract it see the section on [[Schmitt Triggers]]</P>		<P>Most switches are mechanical and vibrate when switched from one position to another. To learn about this and how to counteract it see the section on [[Schmitt Triggers]]</P>

			<h4>Connecting a switch to the PC/104 Stack</h4>

			Because a switch functions as a digital device, we will be connecting to a digital IN port on the PC/104. You should consult the [[PC104 I/O]] page first. Below is a picture of how you might connect a pushbutton switch.

			[[image:switchpc104.jpg\|thumb\|500px\|center]]

Stephens at 19:58, 9 June 2006

2006-06-09T19:58:37Z

← Older revision		Revision as of 14:58, 9 June 2006
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	A switch is a device that is used for making and breaking electrical connections in a circuit. There are many types of these devices. Some of the more common ones that you may use are shown below. (microswitch, pushbutton, toggle, dip, slide, rotary)</P>		A switch is a device that is used for making and breaking electrical connections in a circuit. There are many types of these devices. Some of the more common ones that you may use are shown below. (microswitch, pushbutton, toggle, dip, slide, rotary)</P>

Stephens at 19:58, 9 June 2006

2006-06-09T19:58:30Z

← Older revision		Revision as of 14:58, 9 June 2006
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			__NOTOC__

	A switch is a device that is used for making and breaking electrical connections in a circuit. There are many types of these devices. Some of the more common ones that you may use are shown below. (microswitch, pushbutton, toggle, dip, slide, rotary)</P>		A switch is a device that is used for making and breaking electrical connections in a circuit. There are many types of these devices. Some of the more common ones that you may use are shown below. (microswitch, pushbutton, toggle, dip, slide, rotary)</P>

Stephens at 19:57, 9 June 2006

2006-06-09T19:57:24Z

← Older revision		Revision as of 14:57, 9 June 2006
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	<P>The following figure shows how a single throw switch can be wired to a sensor input port. When the switch is opened, the sensor input is pulled to the +5V supply by the pull up resistor. When the switch is closed, the input is tied to ground, generating a zero voltage signal. A double throw switch makes life much easier but they are less common.</P>		<P>The following figure shows how a single throw switch can be wired to a sensor input port. When the switch is opened, the sensor input is pulled to the +5V supply by the pull up resistor. When the switch is closed, the input is tied to ground, generating a zero voltage signal. A double throw switch makes life much easier but they are less common.</P>

			{\|
⚫	[[image:switch_ex1.gif~~\|246px~~]]
			\|-
		⚫	\|[[image:switch_ex1.gif]]
			\|[[image:switch_ex2.gif]]
			\|}

	<h4>Switch Debouncing</h4>		<h4>Switch Debouncing</h4>

Stephens at 19:56, 9 June 2006

2006-06-09T19:56:03Z

New page

A switch is a device that is used for making and breaking electrical connections in a circuit. There are many types of these devices. Some of the more common ones that you may use are shown below. (microswitch, pushbutton, toggle, dip, slide, rotary)</P>

<H4>Switch Terminology</H4>

[[image:switch1.gif|350px|right]]
<p>Beside the general type of switch (toggle, slide, pushbutton, etc) there are many configurations of the contacts possible. Often you will see a switch in a schematic referred to as a SPST or DPDT. These stand for Single Pole Single Throw and Double Pole Double Throw. This is illustrated in the diagram at the right. A switch with a single throw has it's lines either connected or unconnected. In otherwords there are two terminals with are electrically connected only when the switch is activated. A switch with a double throw has an extra terminal for each pole so that there are two electrical paths possible instead of just one. </p>

<p>Another term used often with switches is Normally Open or Normally Closed. Most pushbutton-style switches are "normally open", meaning that the switch contacts are in the open-circuit position when the switch is in the non-depressed state. Microswitches often have both normally open and normally closed contacts and a common contact. When wiring a touch sensor with a microswitch, it is customary to use the normally open mode. </p>

<H4>Two common uses of switches in mechatronics are power cutoff and as an imput sensor. </H4>

<p>The microswitch is a type of touch sensors. A microswitches is a small, momentary switches that can be attached to bumpers to signal when the robot has run into an obstacle. A microswitch is housed in a rectangular body and has a very small buton whcih is the external switching point. Usually, microswitches are also equipped with lever arms to reduce the force needed to actuate the switch.</p>
<H4>Switch Circuitry</H4>

<P>The following figure shows how a single throw switch can be wired to a sensor input port. When the switch is opened, the sensor input is pulled to the +5V supply by the pull up resistor. When the switch is closed, the input is tied to ground, generating a zero voltage signal. A double throw switch makes life much easier but they are less common.</P>

[[image:switch_ex1.gif|246px]]

<h4>Switch Debouncing</h4>

<P>Most switches are mechanical and vibrate when switched from one position to another. To learn about this and how to counteract it see the section on [[Schmitt Triggers]]</P>