silly power supply

John Larkin · 2017-01-11T05:51:14+00:00

I'm doing an arbitrary waveform generator that uses a bunch of THS6022 monster opamps for the outputs. I have +-12 volt VME supples that could droop as low as 11.5 maybe. I need +-10 volts of output swing into 100 ohms, and the supplies are literally a couple of tenths of a volt away from working. How annoying. Various boost regs look like overkill to do this, to boost the supplies a half volt or so. This dumb open-loop thing might work. I can get the 5v p-p square wave off the +5 supply, chop it up with a couple of mosfets. This is another use for those cute Coilcraft dual-winding inductors. I can get the schottky bridge as a single surface-mount part. The negative side is the same idea, using the same 5v p-p source. Version 4 SHEET 1 1924 740 WIRE 80 -688 -16 -688 WIRE 256 -688 144 -688 WIRE 384 -688 256 -688 WIRE 544 -688 448 -688 WIRE 256 -656 256 -688 WIRE -16 -560 -16 -688 WIRE 80 -560 -16 -560 WIRE 256 -560 256 -576 WIRE 256 -560 144 -560 WIRE 384 -560 256 -560 WIRE 544 -560 544 -688 WIRE 544 -560 448 -560 WIRE 784 -560 544 -560 WIRE 880 -560 784 -560 WIRE 960 -560 880 -560 WIRE 544 -528 544 -560 WIRE -16 -496 -16 -560 WIRE 784 -496 784 -560 WIRE -16 -368 -16 -416 WIRE 544 -368 544 -464 WIRE 784 -368 784 -416 WIRE 192 -192 -16 -192 WIRE 368 -192 256 -192 WIRE 544 -192 448 -192 WIRE -16 -144 -16 -192 WIRE 544 -128 544 -192 WIRE -16 -16 -16 -64 FLAG 784 -368 0 FLAG 880 -560 POS FLAG -16 -368 0 FLAG -16 -16 0 FLAG 544 -128 0 FLAG 544 -368 0 SYMBOL ind2 352 -176 R270 WINDOW 0 -47 57 VTop 2 WINDOW 3 -57 56 VBottom 2 SYMATTR InstName L1 SYMATTR Type ind SYMATTR SpiceLine Rser=0.33 SYMBOL schottky 384 -544 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D1 SYMATTR Value RSX205L-30 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 528 -528 R0 WINDOW 0 65 34 Left 2 WINDOW 3 61 72 Left 2 SYMATTR InstName C2 SYMBOL current 784 -496 R0 WINDOW 0 78 6 Left 2 WINDOW 3 -168 174 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName I1...

silly power supply

Jan 11, 2017 62 Replies

Rate this thread:

piglet 9 years ago

Sorry, ignore silly piglet. Didn't read carefully.

That over-driven follower trick is nice, thanks.

piglet

Vote

tabbypurr 9 years ago

1A 50ohms is 50v, I thought you were using +-12v rails. Multiple outputs?

that approach would avoid the first crest distortion issue.

Of course, with a different basket of issues. One could take it further to improve efficiency etc etc.

Vote

John Larkin 9 years ago

Yes, eight total outputs, each making up to 10 volts, 50 ohms internal source termination. That's 100 mA per output into a customer 50 ohm load, plus a little overhead current. It's worse if the customer shorts the outputs, but I'll tell them not to do that.

Four channels about like this:

formatting link

John Larkin Highland Technology, Inc lunatic fringe electronics

Vote

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required