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| Understanding this signal conditioning circuit |
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| Red_Micro:
Hi, The circuit attached is used to condition a signal coming from a CT that detects very low currents. I don't fully understand this circuit. What's the purpose of C4? It is obviously reducing the original amplitude of the signal. I'm trying to simplify this circuit where possible using a simpler precision rectifier. Any comments on the overall operation of this circuit will be appreciated. |
| bob91343:
My guess is that C4 is used to stabilize the amplifier. In other words, without it we have the gain set by the feedback resistors. With it, the low frequency gain is reduced to unity. |
| mk_:
try a square at your signal source CT instead a sine and see what happens |
| awallin:
C4 and R6 make a high-pass with a time-constant of C4*R6=44 ms. if you are measuring 60Hz AC it has a period of 17ms. so C4 is there just to AC-couple the whole measurement, if you are not interested in signals that are slower than ~44ms. |
| Red_Micro:
Another thing is the circuit is using dual power supply. I think that using a precision rectifier will allow me to use just single power supply, right? I want to use an ADC and scale the signal between 0-3.3V. |
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