Convert bipolar opamp circuit to single rail psu ?

Started by andrew_k, July 01, 2009, 06:59:08 AM

Previous topic - Next topic

andrew_k

I'd like to use this circuit (two in a stereo pair), but I only have a a +12V supply available -


From here - http://koti.mbnet.fi/siliconf/JukkaTolonen/ga/peakmtr/peakmtr.html

What's my best option? TC1044 or similar to split and then another pair to pump up each side to +12/-12?

fuzzo

you can create a bias to 6V, in creating a voltage divider with your 12V (the same thing with 9V power supply and its 4V5 at Vr)

But, I think ,  you can make a symetric power supply with 12V if you use a transfomer, you need four diodes and regulators.

What does this schemo ?

Minion

Is your 12v AC or DC ?? If it is AC you can make a Full wave Voltage doubler and get +/-15v DC from a 12v AC supply ..... it"s a neat trick to get dual voltages from a single AC supply ....

Cheers
Go to bed with itchy Bum , wake up with stinky finger !!

andrew_k

#3
Quote from: fuzzo on July 01, 2009, 10:36:23 AM
What does this schemo ?
It's a peak level indicator using a "magic eye" valve.

I had considered the psuedo -6/+6 using a voltage divider off +12 for vref, but headroom is a concern. This is part of an all-valve microphone preamp with 70dB of gain. I'm going to great lengths to ensure quiet operation, so I'd hate for this to add noise. Although being a peak meter it will be at the end of each channel, but the buffer is still in direct contact with the output...

Minion: It is 12Vdc, unfortunately. Rectified filament supply for 4 valves. And the power supply is external, connected by a 4 prong cable (+12/+250/+48/GND), so I have no choice but to work with what I have available. The +48 supply is very low current and is barely enough to supply phantom power to two channels, so I'm not using that one. If you're the same Minion from the prodigy pro forum, you might know about this preamp -- it's a dual version of NYDave's MILA.

I have some traditional VU meters that I can use; but I also have a few magic eye tubes and a healthy high voltage supply available, so if I can use those instead that would be pretty cool  ;D