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[DPRG] thermal glue

Subject: [DPRG] thermal glue
From: rten at new.metronet.com rten at new.metronet.com
Date: Mon Dec 23 16:57:01 CST 2002

Daryl:
If you add mass to the heat sink, such as heavy copper wire, attach it
with thermal glue. Otherwise you won't get good heat transfer and you will
be just inhibiting free air access to the heat sink.
Ralph

On Mon, 23 Dec 2002, Daryl Gallatin wrote:

> 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 shaft
>
>
> 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 to
>
> I got the idea to use this H-bridge from www.kronosrobotics.com because it said this controller was low noise
>
>
> Thanks!
>
>
>
>
> >>> "David Peterson" <robodave1 at attbi.com> 12/23/02 15:58 PM >>>
>   Daryl, you may have a bit too small of an h-bridge to use on the motor if
> the chip is getting hot from just free running. Usually each motor has some
> type of number on it and a manufacturer. Of the type from Tanners that might
> cause heat on a 754410 in free run, no load on the shaft, there are some
> that resemble Johnson screwdriver/vacuum motors, that are about 2 inch in
> diameter, maybe 3 inch long. These could have a stall that easily exceeds
> the specs that the 754410 will drive. Specifics about what motor you have
> could be really helpful, as in what numbers or markings are on the case.
>
>   Also it may be possible that you have a litte miswire somewhere. A high or
> 1 or +5 should be to the 1,2EN enable, a high to the 1A input and a low to
> the 2A input associated with 1Y and 2Y motor outputs connected to the motor
> leads to turn one direction, reverse the 1A and 2A signals to turn the motor
> the other direction.
>    About using a ground plane, currently not an option using a wire wrapped
> circuit. You are left with attaching a heat sink, possibly even wrapping
> some bare wires over the sink and under the 4 ground pins only, for a form
> of mechanical bond and a little additional heat transfer. Hummingmotors
> aren't a bad thing, can just get annoying after a while.
>
> ----- Original Message -----
> From: "Daryl Gallatin" <dgall723 at mail.dal.devry.edu>
> To: <DPRGlist at dprg.org>
> Sent: Monday, December 23, 2002 2:28 PM
> Subject: Re: RE: [DPRG] thermal glue
>
>
> > Ok I will try that
> >
> >
> > The 50hz PWM may be a problem too, like it has been suggested.
> >
> > I thought the motor was turning, when in fact it wasn't
> > It was on, but not turning and the voltage ion both nputs on the motor
> were approxiametly .25 volts. Like it was locked.
> >
> > I have tested it without PWM and just had a 1 to the enable pins, that
> turned the motors(very fast) but it still got hot.
> >
> > SO I need to use a freq between 500hz and 5k?
> >
> > I had read that using it in the hearing range can cause the motor to hum
> >
> >
> > My H0bridge, and opto isolators are wire wrapped. Is therea way to use
> this ground plate?
> >
> >
> >
> > I do not have specs on the motors. I picked them up at tanners to use as
> test motors.
> >
> >
> > Thanks!
> >
> >
>
>
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