Allen Demers wrote:

> On 04/20/98 22:46:42 you wrote:
> >
> >Thank you all for your responses on my heatsink question.
> >
> >I didn't know how to read the databook w/ regards to heat.
> >Also, If I am using a 7805, and my source voltage is the car's battery,
> >at least is 13 volts when car is in operation, so 13v-5v=8Volt drop.
> >8*.75amp load = 6 Watts!!  6 watts * ~50 deg C per == 300 degree C.
> >
> >Double that of a rated junction temperature of 150 Degrees C!!!
> >
>
> *novice notice: Not much electronic experiance here*
> but I am learning! :)
>
> Would a pelitier heat pump IC work(maybe a few!) work? Using some of these may also use up some
> of that extra energy you have lying around!
>
> Anyone let me know of any pitfalls with this please.

Consider this : A typical 5V peltier wil guzzle up around 1A in order
to shift a few watts from one side to the other. Instead of 6W, you
now have 11W to deal with (excluding the supply for the peltier).

It will be far, far, far cheaper to go with switch mode.

--
Friendly Regards

Tjaart van der Walt
mailto:tjaart@wasp.co.za

|--------------------------------------------------|
|                WASP International                |
|R&D Engineer : GSM peripheral services development|
|--------------------------------------------------|
|SMS mailto: 0832123443@wasp.co.za  (160 chars max)|
|     http://www.wasp.co.za/~tjaart/index.html     |
|Voice: +27-(0)11-622-8686  Fax: +27-(0)11-622-8973|
|          WGS-84 : 26¡10.52'S 28¡06.19'E          |
|--------------------------------------------------|