Abstract: An oscillator utilizing a voltage comparator having hysteresis characteristics for producing a pulse train. The width of the pulses in the train is controlled by the charging rate of a capacitor coupled to one input of the comparator and the period of the pulse train is controlled by the discharge rate of this capacitor. The discharge rate and hence the oscillator frequency may be varied in response to a control voltage. Compensating elements ensure that the pulse width is highly stable with respect to temperature variations. The oscillator when in a feedback control circuit, produces oscillations at a frequency whose value is linearly related to the feedback control voltage.

Abstract: A plurality of transistors are connected in series together with a load across a source of operating potential. A primary bias circuit coupled to the transistors apportions the voltage across each transistor under quiescent conditions. A supplementary bias circuit, activated when the potential across one of the transistors is within a given range, supplies additional bias to other of the transistors of the series circuit.