On Tue, 30 Dec 2003 03:19:37 -0800, Watson A.Name - "Watt Sun, Dark
Remover" said...
In article t,
mentioned...
On Mon, 29 Dec 2003 20:36:46 GMT,
said...
On Mon, 29 Dec 2003 20:16:37 GMT, what
said...
On Mon, 29 Dec 2003 20:12:23 GMT, the renowned Active8
,invalid wrote:


I'm thinking 4.3V Zener and a series pass transistor.

Wrong way.

Best regards,
Spehro Pefhany

Why?

NEver mind. I tried to cancel this but Gravity thinks I didn't post
this.

Still at TARFU level, I guess.

OK 5.6V zener, solly.

I think the emitter to base voltage will be something like .6 to .75V,
and this has to be subtracted from the 1V diff, leaving something like
.4 to .25V. This very low voltage is what you have to work with when
coming up with the resistor value to limit the current to the zener.


Rough guess...



---+------------------+
| |
| 10 |
| ___ |/
+---|___|---+----|
| |
| |
- |
5.6 500mW ^ +---------
|
-------------+----------------


I kinda like JT's deal with the programmable zener which ain't much
different.

--
Best Regards,
Mike