Combine AC and DC signal (15A)
Combine AC and DC signal (15A)
(OP)
It is easy to combine two lower power signal into 1 signal using inverted-summing opt-amps circuit.
Now I would like to combine these 2 signals,
4v DC signal with a 0.5V AC (but its current is 30A - very high). What is the best way/ device to combine these signals.
Now I would like to combine these 2 signals,
4v DC signal with a 0.5V AC (but its current is 30A - very high). What is the best way/ device to combine these signals.





RE: Combine AC and DC signal (15A)
It's non-trivial, so please provide more details about the specific application.
RE: Combine AC and DC signal (15A)
RE: Combine AC and DC signal (15A)
RE: Combine AC and DC signal (15A)
RE: Combine AC and DC signal (15A)
Think gets hard because I do not want to supply a purely DC signal. I want to have a small AC signal runs on top of the DC signal but the combination signal must supply a high current (I want at have least 30A)
(0-10VDC)+/-0.5VAC ~30A
RE: Combine AC and DC signal (15A)
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If we learn from our mistakes I'm getting a great education!
RE: Combine AC and DC signal (15A)
(You can avoid much confusion by not using the word "signal" to refer to the output from a power supply.)
It all depends on the frequency of the AC control signal. If it is on its own frequency that is reasonably high, and is separate from the line frequency, separate from any switching frequency, and separate from any noise induced by the load, then it becomes easy to extract it.
But if you're contemplating using AC at the same 50/60 Hz frequency as the noise and ripple on the output, then it's going to be difficult to extract the information accurately.
Also, a DC power supply is typically designed to "fight" any AC on the output. It'll be an ultra low impedance load when you try to impose low frequency AC into the output pins of a DC power supply whose purpose in life is to keep noise off the output.
RE: Combine AC and DC signal (15A)
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Combine AC and DC signal (15A)
RE: Combine AC and DC signal (15A)
RE: Combine AC and DC signal (15A)
Any 30A power supply is going to have remote sensing. Sense and power are usually internally connected with about a 100 resistor so it doesn't go wild if the sense is disconnected. Just feed a signal into that sense pin through a capacitor and resistor. Most supplies should handle the low frequencies pretty well.