Abstract: An abnormal voltage detection circuit includes a series circuit of a resistor and a capacitor coupled across a power source by means of a switch, an inverter with the input terminal coupled to the junction of the resistor and capacitor, and an R-S flip-flop circuit with the set and reset input terminals coupled to the output terminal of the inverter and a manual switch respectively. The R-S flip-flop circuit is set by a first threshold voltage lower than the threshold voltage of the inverter, and reset by a second threshold voltage higher than the threshold voltage of the inverter.

Abstract: An integrated driver circuit comprises a signal-generating circuit for sending forth output signals when a power source voltage is impressed thereto; a level converting means for changing the level of one of the output signals into a control signal having a voltage n-fold (n>1) larger than the power source voltage; and at least one field effect transistor arranged to be rendered conducting or non-conducting according to said control signal for selective actuation of external display means provided outside of the integrated driver circuit.

Abstract: This negative resistance network includes a first predetermined channel insulated gate enhancement type field effect transistor having a drain-source path connected to positive and negative input terminals on which a predetermined input voltage is impressed.