Getting 12v & 15v & 16v from a 16v supply?

I have an existing 16v supply, and i would like to run 12v and 15v off it also. But i cannot modify the original supply... I

Can i just put a 78L12/79L12 & 7815/7915 vreg circuit with some smoothing caps off the original regulated 16v circuit? So i'd effectively have 12v, 15v, and 16v rails?

You can do the 12V supply fine. 15V will be a little harder, as you're mighty close to the dropout voltage of the regulator. You might want to do that one with a zener diode, dropping resistor and filter capacitor, if that's an adequately regulated supply for your application.

What exactly will you be driving with those voltages?

Peace,
Paul

[quote author="pstamler"]You can do the 12V supply fine. 15V will be a little harder, as you're mighty close to the dropout voltage of the regulator. You might want to do that one with a zener diode, dropping resistor and filter capacitor, if that's an adequately regulated supply for your application.

What exactly will you be driving with those voltages?

Peace,
Paul[/quote]

It's a mono GSSL so its 2 NE5534's, a NE5532, a TL074, a TLO72 and 2 THAT2180's.

You can also use a (very) low-dropout regulator for the 15V supply, but the zener route may be safer/easier.

Is the original 16V supply regulated?

Best regards,

Mikkel C. Simonsen

[quote author="mcs"]You can also use a (very) low-dropout regulator for the 15V supply, but the zener route may be safer/easier.

Is the original 16V supply regulated?

Best regards,

Mikkel C. Simonsen[/quote]


Yup it is regulated.

The opamps certainly won't mind being run off +/-16V. This is probably true of the VCAs as well, although that depends on what you're using. So, since your supply is already regulated, why not just add 12V regulators and run it as +/-16V and +/-12V?

If you must drop the voltage, putting rectifier diodes in series with the supply output will reduce the voltages to +/-15.3V. Observe correct polarity and current ratings for the diodes. As a bonus, you'll have added reverse-polarity protection which will save the unit from damage if the supply is hooked up backwards.

Now, when you say "16V supply", you DO mean +/-16V, right? If it's just a single-ended 16V supply, it's useless for this project.

You can run those VCA's off of up to a +/-18vdc supply before you have to make alterations to the circuit. You can actually run them off of +/-24 vdc supplies by using a zener in series with pin 7 and the positive rail, and a 6.9k resistor in series with pin 5 and the negative rail.

Cool news! It dawned on me last night in the closing minutes of consciousness that the opamps can run off voltages greater than 15v but i wasn't sure about the VCA's.

Yup, its a regulated +/- 16v supply.

I'll give it a go just running off 16v and 12v, If i run into any problems i'll try using some series rectifier diodes as you suggest NYD


Thanks for your help guys. It is much appreciated! :guinness: :guinness: