Difference between revisions of "PC104 Power"

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===Power and battery life===
<table>

<tr valign="middle">
The whole stack, including the BoB, DAQ, and CPU boards, needs
<td>
<p><strong> Power and battery life</strong></p>
<p>The whole stack, including the BoB, DAQ, and CPU boards, needs
about 1.3 amps at 5VDC. If you are running the WET54G ethernet
about 1.3 amps at 5VDC. If you are running the WET54G ethernet
bridge as well, the total will be just under 2A. Any current your
bridge as well, the total will be just under 2A. Any current your
project draws from BoB's 5VDC supply (or its +12 and -12 VDC
project draws from BoB's 5VDC supply (or its +12 and -12 VDC
supplies) will add to that total.</p>
supplies) will add to that total.

<p>BoB generates its 5VDC by using a DCDC converter described
BoB generates its 5VDC by using a DCDC converter described
earlier. This DCDC converter is quite flexible about its input
earlier. This DCDC converter is quite flexible about its input
voltage; it's happy with anything in the range of 9-18 VDC.</p>
voltage; it's happy with anything in the range of 9-18 VDC.
*[[media:DCDC_SC15A.pdf|SC15A11 DCDC converter]]
<ul>

<li><a href="../contents/DCDC_SC15A.pdf">SC15A11 DCDC
[[image:Img0067b.jpg|right|300px]]
converter</a></li>

</ul>
<br clear="all">
<p> </p>

</td>
<td><a href="big/Img0067b.jpg"><img src="300/Img0067b.jpg" width=
"300" height="151" border="0"></a></td>
</tr>
<tr valign="middle">
<td colspan="2">
<hr size="1">
<hr size="1">

</td>
There are a number of ways to provide 9-18 volts to the DCDC
</tr>
<tr valign="middle">
<td>
<p>There are a number of ways to provide 9-18 volts to the DCDC
converter. Most of the time you can use a plug-in adapter. The
converter. Most of the time you can use a plug-in adapter. The
one shown provides a regulated 12VDC at up to 1.5A</p>
one shown provides a regulated 12VDC at up to 1.5A

<p>In practice, the stack (with the wifi bridge) needs 2A at
In practice, the stack (with the wifi bridge) needs 2A at
5VDC, which is 10 watts. The plug-in adapter will be providing
5VDC, which is 10 watts. The plug-in adapter will be providing
only about 1A at 12VDC, which is 12 watts, to feed the DCDC
only about 1A at 12VDC, which is 12 watts, to feed the DCDC
converter. The DCDC converter is evidently about about 86%
converter. The DCDC converter is evidently about about 86%
efficient (10W/12W=86%).</p>
efficient (10W/12W=86%).

<p>The DCDC converter can provide up to 3A of current at
The DCDC converter can provide up to 3A of current at
5VDC.</p>
5VDC.
<ul>

<li><a href="../contents/ACDC_Jameco312864.pdf">Wall-plug
switching supply 12VDC 1.5A</a></li>
*[[media:ACDC_Jameco312864.pdf|Wall-plug switching supply 12VDC 1.5A]]

</ul>
[[image:Img0163.jpg|right|300px]]
</td>

<td><a href="big/Img0163.jpg"><img src="300/Img0163.jpg" width=
<br clear="all">
"300" height="228" border="0"></a></td>

</tr>
<tr valign="middle">
<td colspan="2">
<hr size="1">
<hr size="1">

</td>
The wall-plug switching power supply has a barrel-type
</tr>
<tr valign="middle">
<td>
<p>The wall-plug switching power supply has a barrel-type
connector; male on the supply and female on BoB (there is some
connector; male on the supply and female on BoB (there is some
ambiguity about the anatomy.)</p>
ambiguity about the anatomy.)

<p>There are a lot of barrel type connectors. The ones we will be
There are a lot of barrel type connectors. The ones we will be
using for 9-18VDC are 5.5/2.1mm, which are the OD and ID of the
using for 9-18VDC are 5.5/2.1mm, which are the OD and ID of the
plug respectively.</p>
plug respectively.

<p>5.5/2.5mm plugs and jacks are quite common too; both are shown
5.5/2.5mm plugs and jacks are quite common too; both are shown
in the photo. They are hard to distinguish visually.</p>
in the photo. They are hard to distinguish visually.
<p>Note that BoB has a typo; it says 5.5/2.5 but actually uses

5.5/2.1.</p>
Note that BoB has a typo; it says 5.5/2.5 but actually uses
<p>We will use the more common center-positive convention, which
5.5/2.1.
is what the symbol in the inset shows.</p>

</td>
We will use the more common center-positive convention, which
<td><a href="big/Img0165.jpg"><img src="300/Img0165.jpg" width=
is what the symbol in the inset shows.
"300" height="185" border="0"></a></td>

</tr>
[[image:Img0165.jpg|right|300px]]
<tr valign="middle">

<td colspan="2">
<br clear="all">

<hr size="1">
<hr size="1">

</td>
For mobile projects, you may want to use a rechargeable
</tr>
battery pack. You can use anything in the 9-18VDC range.
<tr valign="middle">

<td>
The one shown is rated 9.6VDC, 2200mAH. It consists of 8 1.2
<p>For mobile projects, you may want to use a rechargeable
battery pack. You can use anything in the 9-18VDC range.</p>
<p>The one shown is rated 9.6VDC, 2200mAH. It consists of 8 1.2
volt NiCd cells in series. That's 21 watt-hours; I found that it
volt NiCd cells in series. That's 21 watt-hours; I found that it
ran the stack (which was consuming 10 watts) for 90 minutes.</p>
ran the stack (which was consuming 10 watts) for 90 minutes.

<ul>
<li><a href="../contents/NiCd_2200MaH.pdf">Discharge curves for
[[media:NiCd_2200MaH.pdf|Discharge curves for 1.2V 2200mAH NiCd cell

1.2V 2200mAH NiCd cell</a></li>
<strong>Warning.</strong> If you short a rechargeable battery
</ul>
<p><strong>Warning.</strong> If you short a rechargeable battery
pack, very large currents will flow. It can get hot very quickly,
pack, very large currents will flow. It can get hot very quickly,
and may catch fire or burst, spattering you with hot caustic
and may catch fire or burst, spattering you with hot caustic
toxic chemicals. <strong>Treat it like a car battery.</strong>
toxic chemicals. <strong>Treat it like a car battery.</strong>
Having a barrel connector on it helps a lot. Loose wires or clips
Having a barrel connector on it helps a lot. Loose wires or clips
are a hazard.</p>
are a hazard.

<p>If you are putting a barrel connector on a battery pack, use a
If you are putting a barrel connector on a battery pack, use a
prefabricated molded connector with wires (as shown in this
prefabricated molded connector with wires (as shown in this
photo); don't use a do-it-yourself connector (as shown in the
photo); don't use a do-it-yourself connector (as shown in the
Line 97: Line 85:
before you strip the other wire. This way the battery's wires
before you strip the other wire. This way the battery's wires
can't touch accidentally while you work on them. Test for
can't touch accidentally while you work on them. Test for
center-positive with a voltmeter.</p>
center-positive with a voltmeter.

</td>
[[image:Img0166.jpg|right|300px]]
<td><a href="big/Img0166.jpg"><img src="300/Img0166.jpg" width=

"300" height="174" border="0"></a></td>
<br clear="all">
</tr>

<tr valign="middle">
<td colspan="2">
<hr size="1">
<hr size="1">

</td>
You can charge a variety of battery packs with this smart
</tr>
<tr valign="middle">
<td>
<p>You can charge a variety of battery packs with this smart
charger. I've added a molded inline jack so that it connects
charger. I've added a molded inline jack so that it connects
easily to the battery pack. There's an inline fuse, too.</p>
easily to the battery pack. There's an inline fuse, too.

<p>Do not use clips.</p>
Do not use clips.
<ul>

<li><a href="../contents/SmartChargerInstructions.pdf">Charger
*[[media:SmartChargerInstructions.pdf|Charger instructions]]
instructions</a></li>

</ul>
[[image:Img0162.jpg|right|300px]]
</td>

<td><a href="big/Img0162.jpg"><img src="300/Img0162.jpg" width=
<br clear="all">
"300" height="166" border="0"></a></td>

</tr>
<tr valign="middle">
<td colspan="2">
<hr size="1">
<hr size="1">

</td>
You are also welcome to make up your own battery pack out of
</tr>
<tr valign="middle">
<td>
<p>You are also welcome to make up your own battery pack out of
rechargeable AA cells, which are now easy to get up to 2500mAH.
rechargeable AA cells, which are now easy to get up to 2500mAH.
The smart charger above will handle up to 10 of them in series, a
The smart charger above will handle up to 10 of them in series, a
nominal 12V pack.</p>
nominal 12V pack.

<p>Or you can use off-the-shelf chargers like the one shown
Or you can use off-the-shelf chargers like the one shown
here.</p>
here.
</td>

<td><a href="big/Img0180.jpg"><img src="300/Img0180.jpg" width=
[[image:|right|300px]]
"300" height="226" border="0"></a></td>

</tr>
<tr valign="middle">
<br clear="all">

<td colspan="2">
<hr size="1">
<hr size="1">

</td>
12 rechargeable AA cells, 2500mAH each, gives a whopping 36
</tr>
<tr valign="middle">
<td>
<p>12 rechargeable AA cells, 2500mAH each, gives a whopping 36
WH, which ought to run the stack and wifi bridge (at 2A, 5V) for
WH, which ought to run the stack and wifi bridge (at 2A, 5V) for
about 2.5 hours.</p>
about 2.5 hours.

</td>
[[image:Img0182.jpg|right|300px]]
<td><img src="300/Img0182.jpg" width="300" height="157"></td>

</tr>
<tr valign="middle">
<br clear="all">

<td colspan="2"><strong><a name="usingpower"></a></strong>
<hr size="1">
<hr size="1">

</td>
===Power for your project===
</tr>

<tr valign="middle">
You can draw power for the electronics of your project from
<td>
BoB's DCDC converters.
<p><strong>Power for your project</strong></p>

<p>You can draw power for the electronics of your project from
Up to 1A at 5VDC and 100mA at +12 and -12 are available. If
BoB's DCDC converters.</p>
<p>Up to 1A at 5VDC and 100mA at +12 and -12 are available. If
you exceed the capabilities of the DCDC converters, they will
you exceed the capabilities of the DCDC converters, they will
"hiccup", shutting down and trying to restart over and over. You
"hiccup", shutting down and trying to restart over and over. You
will see the +5 and +/-12 indicator LEDs go on and off if this
will see the +5 and +/-12 indicator LEDs go on and off if this
happens.</p>
happens.

<p>You can use the terminal block to make connections, or a
You can use the terminal block to make connections, or a
ribbon cable. The pinout for the ribbon cable is shown above it.
ribbon cable. The pinout for the ribbon cable is shown above it.
Pin 1 is on the upper right, and is the brown wire in the photo.
Pin 1 is on the upper right, and is the brown wire in the photo.
It's labeled "0" for ground.</p>
It's labeled "0" for ground.
[[image:Img0168.jpg|right|300px]]
</td>

<td><a href="big/Img0168.jpg"><img src="300/Img0168.jpg" width=
<br clear="all">
"300" height="176" border="0"></a></td>

</tr>
<tr valign="middle">
<td colspan="2">
<hr size="1">
<hr size="1">

</td>
Do not use BoB's supplies for running motors and other high
</tr>
<tr valign="middle">
<td>
<p>Do not use BoB's supplies for running motors and other high
power things. In fact ideally you should use a separate battery
power things. In fact ideally you should use a separate battery
pack for these, not share the one that powers the stack.</p>
pack for these, not share the one that powers the stack.

<p>To power the WET54G ethernet bridge, use a molded 5.5/2.5mm
To power the WET54G ethernet bridge, use a molded 5.5/2.5mm
barrel connector and cable, and connect it (center-positive) to
barrel connector and cable, and connect it (center-positive) to
the +5VDC and ground connections of BoB.</p>
the +5VDC and ground connections of BoB.

<p>Don't connect your 12VDC chargers or wall-plug supplies or
Don't connect your 12VDC chargers or wall-plug supplies or
battery packs to the ethernet bridge, which expects 5VDC. We'll
battery packs to the ethernet bridge, which expects 5VDC. We'll
try to stick to this convention:</p>
try to stick to this convention:

<ul>
<li>5.5/2.1mm barrel connectors ... 12VDC</li>
*5.5/2.1mm barrel connectors ... 12VDC
<li>5.5/2.5mm barrel connectors ... 5VDC</li>
*5.5/2.5mm barrel connectors ... 5VDC

</ul>
<p>Suppliers for all parts are listed on the parts list</p>
Suppliers for all parts are listed on the parts list

<ul>
<li><a href="../contents/BoB_partslist_526_2005-12-28.xls">Parts
[[media:BoB_partslist_526_2005-12-28.xls|Parts list]]

list</a></li>
[[image:Img0170.jpg|right|300px]]
</ul>

</td>
<br clear="all">
<td><a href="big/Img0170.jpg"><img src="300/Img0170.jpg" width=

"300" height="182" border="0"></a></td>
</tr>
</table>





Revision as of 11:45, 18 July 2006

Power and battery life

The whole stack, including the BoB, DAQ, and CPU boards, needs about 1.3 amps at 5VDC. If you are running the WET54G ethernet bridge as well, the total will be just under 2A. Any current your project draws from BoB's 5VDC supply (or its +12 and -12 VDC supplies) will add to that total.

BoB generates its 5VDC by using a DCDC converter described earlier. This DCDC converter is quite flexible about its input voltage; it's happy with anything in the range of 9-18 VDC.

Img0067b.jpg



There are a number of ways to provide 9-18 volts to the DCDC converter. Most of the time you can use a plug-in adapter. The one shown provides a regulated 12VDC at up to 1.5A

In practice, the stack (with the wifi bridge) needs 2A at 5VDC, which is 10 watts. The plug-in adapter will be providing only about 1A at 12VDC, which is 12 watts, to feed the DCDC converter. The DCDC converter is evidently about about 86% efficient (10W/12W=86%).

The DCDC converter can provide up to 3A of current at 5VDC.

Img0163.jpg



The wall-plug switching power supply has a barrel-type connector; male on the supply and female on BoB (there is some ambiguity about the anatomy.)

There are a lot of barrel type connectors. The ones we will be using for 9-18VDC are 5.5/2.1mm, which are the OD and ID of the plug respectively.

5.5/2.5mm plugs and jacks are quite common too; both are shown in the photo. They are hard to distinguish visually.

Note that BoB has a typo; it says 5.5/2.5 but actually uses 5.5/2.1.

We will use the more common center-positive convention, which is what the symbol in the inset shows.

Img0165.jpg



For mobile projects, you may want to use a rechargeable battery pack. You can use anything in the 9-18VDC range.

The one shown is rated 9.6VDC, 2200mAH. It consists of 8 1.2 volt NiCd cells in series. That's 21 watt-hours; I found that it ran the stack (which was consuming 10 watts) for 90 minutes.

[[media:NiCd_2200MaH.pdf|Discharge curves for 1.2V 2200mAH NiCd cell

Warning. If you short a rechargeable battery pack, very large currents will flow. It can get hot very quickly, and may catch fire or burst, spattering you with hot caustic toxic chemicals. Treat it like a car battery. Having a barrel connector on it helps a lot. Loose wires or clips are a hazard.

If you are putting a barrel connector on a battery pack, use a prefabricated molded connector with wires (as shown in this photo); don't use a do-it-yourself connector (as shown in the previous photo) which is prone to shorts. Strip one wire from the battery pack and solder it to the molded cord and insulate it, before you strip the other wire. This way the battery's wires can't touch accidentally while you work on them. Test for center-positive with a voltmeter.

Img0166.jpg



You can charge a variety of battery packs with this smart charger. I've added a molded inline jack so that it connects easily to the battery pack. There's an inline fuse, too.

Do not use clips.

Img0162.jpg



You are also welcome to make up your own battery pack out of rechargeable AA cells, which are now easy to get up to 2500mAH. The smart charger above will handle up to 10 of them in series, a nominal 12V pack.

Or you can use off-the-shelf chargers like the one shown here.

[[image:|right|300px]]



12 rechargeable AA cells, 2500mAH each, gives a whopping 36 WH, which ought to run the stack and wifi bridge (at 2A, 5V) for about 2.5 hours.

Img0182.jpg



Power for your project

You can draw power for the electronics of your project from BoB's DCDC converters.

Up to 1A at 5VDC and 100mA at +12 and -12 are available. If you exceed the capabilities of the DCDC converters, they will "hiccup", shutting down and trying to restart over and over. You will see the +5 and +/-12 indicator LEDs go on and off if this happens.

You can use the terminal block to make connections, or a ribbon cable. The pinout for the ribbon cable is shown above it. Pin 1 is on the upper right, and is the brown wire in the photo. It's labeled "0" for ground.

Img0168.jpg



Do not use BoB's supplies for running motors and other high power things. In fact ideally you should use a separate battery pack for these, not share the one that powers the stack.

To power the WET54G ethernet bridge, use a molded 5.5/2.5mm barrel connector and cable, and connect it (center-positive) to the +5VDC and ground connections of BoB.

Don't connect your 12VDC chargers or wall-plug supplies or battery packs to the ethernet bridge, which expects 5VDC. We'll try to stick to this convention:

  • 5.5/2.1mm barrel connectors ... 12VDC
  • 5.5/2.5mm barrel connectors ... 5VDC

Suppliers for all parts are listed on the parts list

Parts list

Img0170.jpg