DC-to-DC voltage-increasing power source

Abstract

A DC-to-DC voltage-increasing power source suitable for use in an audio device mounted on an automobile or a portable type audio device includes a DC power source, a drive pulse generation circuit for generating drive pulses which are in 180 degree phase relationship, a switching circuit of a push-pull connection supplied with operating voltage from the DC power source and driven between an on-state and an off-state in response to the drive pulses, a charge and discharge circuit including capacitors charged by being connected in parallel to the DC power source and discharging a sum voltage by being connected in series to the DC power source and an output takeout circuit for taking out this sum voltage as a voltage-increasing DC output. The switching circuit is constructed of voltage-controlled type elements whose on-state is changed in response to the level of an on-pulse in the drive pulses and the drive pulse generation circuit includes a pulse level changing circuit for changing the level of the on-pulse. in one aspect of the invention, the switching circuit includes a variable time constant circuit for transmitting an on-pulse with a relatively large time constant and an off-pulse with a relatively small time constant.

Dependencies are inferred from the claim text.