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[DPRG] thermal glue

Subject: [DPRG] thermal glue
From: David Peterson robodave1 at attbi.com
Date: Mon Dec 23 20:01:01 CST 2002

Hey Daryl,
  Something does still seem strange. Perhaps a definition of hot? IE, if you
can hold your finger on it, it's probably ok. But still, seems somewhat
strange. The chip could possibly be toasted from the preivious miswire, but
may be fine. Another possible check is to connect your motor in series with
a meter in Amp setting (use the 10 A range or hookup if available) directly
to a 6 volt battery pack. Then you can load the motor a bit by causing a
little friction against the shaft and see just how much current it pulls.
The 754410 itself will drop about 1.2 volts itself before it gets to the
motor, being a bipolar device.
   About wiring a heatsink to the chip, I got the idea from New Micros on
their premade h-bridge module using the 754410. It's their NMIH-0010 that
has a pretty nice setup for hooking it up, complete with a wired and thermal
glued heatsink not shown in the picture. See it at http://www.newmicros.com
and click the H-Bridge button on the side.
  Have no clue about the motor, 503 might be a Johnson or Mabuchi part
number, don't know. If a small FA130 by Mabuchi, it is meant to run at 3
volts, not 6, and would overheat at higher voltages (I've even burned one
out due to this).

----- Original Message -----
>From: "Daryl Gallatin" <dgall723 at mail.dal.devry.edu>
To: <robodave1 at attbi.com>; <DPRGlist at dprg.org>
Sent: Monday, December 23, 2002 4:11 PM
Subject: Re: RE: [DPRG] thermal glue

> There is a number '503' stamped on the motor
> Its about 1" in diamete to 1.5" -2" in lenght. About 3" if you include the
> I did have a mis-wire, but I already fixed that last week.
> I have had it turning before, but it still got a little hot. But that was
free running
> I may try that wire-wrapping the bare wires over the heat sink if I need
> I got the idea to use this H-bridge from www.kronosrobotics.com because it
said this controller was low noise
> Thanks!

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