[sdiy] which zener and current limiting resistor?

[JH.]

Don't use a zener diode.
Use a LM317L and two resistors - it's a much better solution.

JH.


----- Original Message ----- 
From: "keith sterling" <keithsterling at sbcglobal.net>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, August 10, 2006 9:30 PM
Subject: [sdiy] which zener and current limiting resistor?


I have a synth with a +-15V supply and need 16 pots to wipe from 10V to 
GND and 2 pots to wipe from 5V to GND for cv generation.  So I think I 
need 2 zener diodes to generate the 10V and the 5V.  How do I calculate 
the size of the current limiting resistor and current rating of the 
diodes?  My supply doesn't have a lot of headroom so less current drawn 
is better.

I tried using a 2 resistor voltage divider but then every control 
affected all the other controls!  Pretty hard to dial in a sound that 
way!

cheers,
keith sterling