Transistor d.c. convertors

A transistor relaxation-oscillator circuit serving as a direct-voltage step-up device is described. The transistor acts as an interrupter in a low-voltage circuit; energy is stored during the ¿on¿ period in the transformer inductance and is delivered to the output circuit at an increased voltage during the ¿off¿ period. The paper contains a full account of its operating principles and design for efficient power conversion, a brief analysis of voltage-doubler variants and a discussion of the performance and applications of practical d.c. convertors. It also presents some methods of dealing with problems associated with the circuit, such as stabilization of output voltage and fault protection. Transistor convertors have several advantages over competitive methods at power levels of a fraction of a milliwatt up to several watts, such as high efficiency, long life and small size. They therefore promise to become the preferred method of generating h.t. voltages from l.t. supplies at low power levels, except when temperature conditions are unsuitable for the semi-conductor elements employed.