An optronic negative resistance circuit

A negative-resistance circuit has been constructed with the combination of a p-n-p junction transistor, a light emitting p-n diode and a n-p-n photo transistor. The circuit provides negative-resistance voltage-current characteristics in both for increasing and decreasing the positively applied voltage, and holds a facility to obtain external control optically. The breakover voltage can be set at a desired value according to the adjustment of bias resistances for the p-n-p junction transistor.