Control of frequency and phase displacement in transistor converter circuits by means of R-C networks

A new type of adjustable-frequency transistor converter circuit, described in Part I of this paper, differs from conventional transistor converters and from transistor converter circuits incorporating frequency adjustment discussed in previous papers.1¿3 In the new type, the operating frequency is independent of the applied direct voltage ¿ not proportional to it. The switching rate is determined by the time constant of an R-C (resistance-capacitance) network so that no saturating element is required. By making either the resistor or capacitor variable, the frequency is easily controlled over wide limits, and once a setting is made, no appreciable change in frequency occurs despite large variations in the input voltage.