DC voltage converter for vehicle voltage supply system - has FET controlled by regulating stages to provide stabilised output voltage

摘要

An unregulated voltage supply (VB) such as may be provided by a battery in a vehicle system is received by a circuit with an input smoothly capacitor (3). Connection to output (6, 7) is via an FET (4) and inductance (5). A reference voltage is provided by a small battery (10). The battery output is fed to the inputs of a pair of regulators (11, 12), one of which (11) provides a pulse width modulated output and the other (12) an amplitude modulated output. The outputs continuously control the FET via a transformer (15), with a comparator (13) selecting the regulator. ADVANTAGE - Provides regulated output voltage.