🚀 go-pugleaf

In article <1992Sep4.065714.2381@lna.oz.au> randy@lna.oz.au (Randolph CHRISTOPHERS) writes:
>In article <1992Aug27.222807.13917@sequent.com> dwightj@sequent.com (Dwight Johnson) writes:
>>I need to know how to fix our NetModem.  Shiva wants over $250 to even
>>look at it.  I think it should be a one or two component replace job.
>>
>>.....  I checked to 7805 chip inside.  It maintains 25VDC
>>input and 5VDC output even after the modem dies.  It is really hot though.
>>
>Hooly dooly, thats a 20V difference. I don't think 7805's are meant for
>that sort of torture (usually a DC input of less than 10V is OK). Little 
>wonder its cooking.
>
>Randy.

There most be something wrong with your wall-mount transformer.  It should
have an output of 9V AC.  This 9V AC is put through a full-wave rectifer and
then used as the input to the voltage regulator.  If you are see 20V DC at the
input something is wrong.  You should check the output of the wall-mount.
F.Y.I. The regulator input should be somewhere about 9-10V DC depending on the
line voltage.

Chris Outzen
Manager Hardware Development
Shiva Corp