barrelwaves
New Member
Hello, the circuit shown is designed to recieve line level AC sinewave of 1kHz, this signal is then amplified by a gain of roughly 4 to around 2.5v, the output from the TLO71 opamp is sent through a diode removing the AC content and with a low pass filter creating a DC voltage for the transistor to open at 0.7v, this switch is to operate a 5v relay attached to the collector of the transistor. The simulation shows, with a pulsed input to represent the input level going up and down, the relay operating and switching on and off with the input, however, upon physically building this circuit it does nothing of the sort! I have even just isolated the opamp section and have found that it is producing a distorted square wave, just like if there was no feedback resistance and also as if the input is clipping? Starting to drive me a bit mad now so would anyone please be able to help? Is there a problem with the design i am missing? or if anyone has a good experience with the TLO71 opamp then please come forward!
Regards Paul Jones University of Derby, England
Regards Paul Jones University of Derby, England
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