Circuitry processing signals form piezoelectric key - has circuit between piezo-element terminals with resistor(s) and series-connected electronic switch

摘要

The key processing circuitry has a terminal circuit between the piezoelectric key connections with at least one resistor and an electronic switch in series with latter. The switch is controlled by an oscillator to remain open for a given time period, on the key actuation. Pref. the terminal circuit contains a smaller protective resistor and a larger terminal resistor in series. To the junction point of the resistors is coupled an input of an operational amplifier. The output signal of the latter controls the switch to remain open, on the piezoelectric key actuation, at least up to the arrival of a time limiting signal. USE/ADVANTAGE - For computers in specified environments. Improved timing and a facility for integration.