Posted on Oct 23, 2012 11098
This circuit will allow a multimeter to display the positive or negative peaks of an incoming signal. A 741, JC1, is used in the noninverting mode with R1 defining the input impedance. D1 or D2 will conduct on a positive or negative peak, charging C2 until the inverting input is at the same de level as the incoming peak. This level will maintain the voltage until a higher peak is detected, then this will be stored by C2. Another 7 41, IC2, prevents loading by the multimeter.
Connected in the noninverting mode as a unity gain buffer, output impedance is less than 1 !l. This circuit has a useful frequency response from 10Hz to 100 kHz at Â±1 dB. High linearity is ensured by placing the diodes in the feedback loop of JC1, effectively compensating for the 0.6 V bias that these components require.