Here's a question... I just want a low power supply for signal processing, max of a couple dozen op-amps. Not that much current required, but I do want +/- rails.
+/-15VDC would be ideal, however, I'd put up with +/-12V in a pinch.
Of course a SMPS would be a nice thing, but given my lack of success at finding a transormer core, and the low power actually needed, this may be overkill for the application. (Of course I'd preffer overkill to underkill.)
I've seen schematics around for 555 based inverters, which provide the -12V (Or thereabouts) from +12V. This seems to show some promise as being simple, and suitable.
I'm thinking about taking my front stage off of the passive crossover, and bi-amping it. I'd like to use something like Rod Elliot's Project 09 24dB/octave L-R crossover. Just having experienced how much better the 12dB/Octave passive crossover is than the crummy 6dB/octave ones, I'd expect a nice improvement in sound quality and clarity. The stumbling block is that I need a power supply to do it.
The other project that I'd like to work with is Rod's Project 84 8 band subwoofer EQ.
Any suggestions for a power supply?
+/-15VDC would be ideal, however, I'd put up with +/-12V in a pinch.
Of course a SMPS would be a nice thing, but given my lack of success at finding a transormer core, and the low power actually needed, this may be overkill for the application. (Of course I'd preffer overkill to underkill.)
I've seen schematics around for 555 based inverters, which provide the -12V (Or thereabouts) from +12V. This seems to show some promise as being simple, and suitable.
I'm thinking about taking my front stage off of the passive crossover, and bi-amping it. I'd like to use something like Rod Elliot's Project 09 24dB/octave L-R crossover. Just having experienced how much better the 12dB/Octave passive crossover is than the crummy 6dB/octave ones, I'd expect a nice improvement in sound quality and clarity. The stumbling block is that I need a power supply to do it.
The other project that I'd like to work with is Rod's Project 84 8 band subwoofer EQ.
Any suggestions for a power supply?
Op amps can vary a lot in power supply current. And if you want to drive RCA cables, you should strive for 100 ohm source impedance or better, which relates to power. I only mention these things to make you think about what size power supply you really need.
That said, there are self-contained power supply modules available from a number of electronics suppliers. Small size, +/- 15 from 12V in. Go to www.digikey.com and look under power supplies->dc-dc converters. I remember seeing them reasonably cheap.
That said, there are self-contained power supply modules available from a number of electronics suppliers. Small size, +/- 15 from 12V in. Go to www.digikey.com and look under power supplies->dc-dc converters. I remember seeing them reasonably cheap.
It looks like you only need a few watts of power. You could try something like this schematic:
[from www.bobblick.com]
You can make some changes though.
1. You don't need a high power/specialized core for this supply.
2. You don't need an IRFZ44, you need more like an IRF510
3. Use inexpensive 1 amp schottky or fast recovery diodes [like the 1n4933]
4. If you nix the 5v rail, the feedback to the LM3524 should go through a resistor divider [potentiometer] to your +15v out so that you get 15v out. Regulation is a good thing with opamps...
If you don't want to use this, you could use a switched capacitor charge pump to get the supplies but it wouldn't be much simpler IMO.
[from www.bobblick.com]
An externally hosted image should be here but it was not working when we last tested it.
You can make some changes though.
1. You don't need a high power/specialized core for this supply.
2. You don't need an IRFZ44, you need more like an IRF510
3. Use inexpensive 1 amp schottky or fast recovery diodes [like the 1n4933]
4. If you nix the 5v rail, the feedback to the LM3524 should go through a resistor divider [potentiometer] to your +15v out so that you get 15v out. Regulation is a good thing with opamps...
If you don't want to use this, you could use a switched capacitor charge pump to get the supplies but it wouldn't be much simpler IMO.
I had considered tapping off from the amp power supply, but the amps are in the back, and this project is intended to go in the center console (or glovebox.)
I also considered buying a cheap amplifier and just using its power supply, however, since the power supply is usually built on the same board as the amplifier, separating them to make room for my project becomes problematic.
I ordered the Maxim chips as samples, so they're free. If this works out, and seems viable, then I'll see where that takes me.
I also considered buying a cheap amplifier and just using its power supply, however, since the power supply is usually built on the same board as the amplifier, separating them to make room for my project becomes problematic.
I ordered the Maxim chips as samples, so they're free. If this works out, and seems viable, then I'll see where that takes me.
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