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I have a current source that can output different types of waveform depending on the input, including DC (Howland current pump). I need to find a solution as to make sure that when DC is not required it does not appear at the output.

Basically here a series capacitor with the output of the circuit could give me that. It would allow to pass every waveform except for the DC one (when I need DC I could decouple that capacitor).

The problem is that when I attach a resistor as being load my signals could be damaged.

I use 1 Hz frequency, amplitudes from 1 V to let's say 50 Volts with mono and bipolar signals, saw-tooth, triangular signals.

Do you think it helps to place a buffer between the capacitor and the resistor?enter image description here

This would look like a high pass filter, with cutoff at 1Hz.

Later edit

enter image description here

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  • \$\begingroup\$ Is R1 part of your circuit or is R1 "the load"? \$\endgroup\$ – Elliot Alderson Jan 30 at 15:09
  • \$\begingroup\$ Hi, R1 is the load, I need to have a certain current across R1. V1 stands for the current pump's output and I placed the series capacitor to get rid of DC. \$\endgroup\$ – Roadrunner Jan 30 at 15:11
  • \$\begingroup\$ So are you asking for a unity-gain current buffer rather than something like a voltage follower? You want the current out of the buffer to be the same as the current in, regardless of voltage? \$\endgroup\$ – Elliot Alderson Jan 30 at 15:15
  • \$\begingroup\$ I want to have the current i programmed through my current pump across R1 regardless of this safety measure of getting rid of DC component. I was thinking at the high input impedance of an opamp, that's why the buffer \$\endgroup\$ – Roadrunner Jan 30 at 15:18
  • \$\begingroup\$ I just add a pic with my solution, I do not know whether is going to work. \$\endgroup\$ – Roadrunner Jan 30 at 15:27

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