Subject:
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Re: NEW POWER SUPPLY
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Thu, 14 Oct 1999 21:46:38 GMT
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Original-From:
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Nick Taylor <ntaylor@iname.com>
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Viewed:
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620 times
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Great solution Gary! How about just pulling the L293D/SN754410 from
the U11 socket, bending pin-8 out and soldering the REALLY BIG battery
positive lead to it, then soldering the negative lead to pin-1 without
bending it out, and then reinstalling the chip. It doesn't save much
money since there wasn't much money involved, but it does save quite
a bit of time. Biggest benefit is that if you use the HB on more
than one project, all that needs to be done to switch back and forth
is to have an extra chip on hand ... swap the modified chip for the
unmodified one.
Your method provides and very easy way to change the driver chip to
a much higher power chip such as the 298L.
- Nick -
Gary Livick wrote:
>
> This was explained a week or two ago here on the list server. Check back
> and you'll find out what traces to cut, etc.
>
> However, I have found another way that is very simple, and does not require
> you to make difficult-to-fix cuts on your boards. Just add another 16 pin
> socket onto the user area on your expansion board. Remove one of the L293
> chips and set it aside. Use 20 ga solid hook-up wire, and take all the
> signals, the 5v and ground line from the socket with the removed chip over
> to the new socket. You can push the wires into the socket at the old
> location, and solder at the other socket. Don't connect the motor leads
> from the old socket to the new. Instead, connect the motors you want to
> use to the motor output ports on the new socket. Bring the power leads
> from your REALLY BIG battery to the new socket, and connect +12 to pin 8
> and common to the board common (on the socket). Plug the L293 into the new
> socket and hang on, we're goin' places!
>
> I just did this, and it works great. If you have the room for a seperate
> board, you can build this up and include a charger plug-in same as what is
> on the HandyBoard. That way you can use the HandyBoard charger to charge
> your 12 volt gel cell. You can also hang lots of motor-direction LED's and
> a charge light if you want.
>
> Total cost is less than two donuts. Time is about two hours to wire up.
>
> Gary Livick
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Message has 1 Reply:
 | | Re: NEW POWER SUPPLY
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| That is the same thing, except much easier. Plus we save donut money. However, we'd have to look at the effect of 7 volts reverse bias on the motor LED's. Plus, we'd have to make real sure not to short the bent pin 8 to the socket underneath it. (...) (25 years ago, 14-Oct-99, to lugnet.robotics.handyboard)
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Message is in Reply To:
| | Re: NEW POWER SUPPLY
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| This was explained a week or two ago here on the list server. Check back and you'll find out what traces to cut, etc. However, I have found another way that is very simple, and does not require you to make difficult-to-fix cuts on your boards. Just (...) (25 years ago, 14-Oct-99, to lugnet.robotics.handyboard)
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