Safety circuit of automatic transmission control system

摘要

A safety circuit in an automatic transmission control system having a comparator producing a transmission shifting control signal wherein upon comparing a vehicular velocity responsive signal and a throttle opening responsive signal, the safety circuit comprises: a comparator whose inverting input terminal is supplied with the vehicular velocity responsive signal through a capacitor and whose non-inverting input terminal is supplied with a constant voltage signal which is lower than the inverting terminal signal at normal state, the comparator detecting the difference between the two input voltages; a transistor circuit for connecting to ground said transmission shifting control signal; and a latching circuit for latching the output signal of the transistor circuit, whereby an abrupt loss of the vehicluar velocity responsive signal is detected.