COLD CATHODE GAUGE FAST RESPONSE SIGNAL CIRCUIT

摘要

A fast response output signal circuit (10) for a cold cathode gauge is provided to produce a fast response output signal (48) in addition to a voltage output signal (40) that is representative of the pressure in the cold cathode gauge. The fast response output signal (48) is either on or off, thus can be used to trigger a closing of an isolation valve or other responsive action upon a change in pressure that attains or exceeds a certain set point threshold. The fast response output signal is produced and processed with analog circuits, but the set point is produced with a microprocessor. The voltage output signal can be produced as a logarithmic function of the pressure.