pulse detecotr type circuit

[wingman05]

im building a pulse detection type circuit where the input is ac signal consisting of a series of pulses of different amplitudes. the output should be a dc type signal that maintains the peak voltage of the pulse until the next pulse comes along upon which it switches to the peak voltage of that pulse. i had in mind to use 2 half-wave rectifiers and logic gates to turn off and on each rectifier so that while 1 capacitor is charging the other is being read. im not too sure about where it is going but i was wondering if u had any possible ideas on how i could set up a circuit to do that. cheers.

[Kevin Weddle]

Here is the circuit. You don't need rectifier diodes. It will give you the positve cycle on demand and the negative cycle going positive on demand.

[audioguru]

Hi Wingman,
Welcome to our forum.
Do you use an amplitude modulated carrier, like an AM radio?
To quickly store the amplitude of a pulse, then quickly change its voltage to the amplitude of the next pulse, you need a sample-and-hold circuit. It is made with a low-impedance buffer that charges or discharges a capacitor. It is activated by detecting the incoming pulse with a high gain amplifier. You can "read" the cap's voltage with a very high input resistance FET or FET-input opamp.

If your signal has pulses of both polarities, you can use an input transformer like in Kevin's circuit but use a center-tap as a voltage reference. Otherwise you need a full-wave bridge rectifier. His transistors perform like half-wave rectifiers.