DC transformer with transformer primary chopper circuit - containing MOSFET driven by astable multivibrator and FET voltage stabiliser

摘要

A d.c. transformer circuit contains a transformer (1) arrangement with a chopper (3) acting on the d.c. input signal to the transformer with an astable multi-vibrator providing the timing signals. The output stage contains a rectifier (6) and filter (7). Error-free signal transfer is achieved with an arrangement essentially simpler and cheaper than conventional d.c. transformers. The transformer (1) primary winding (8) is connected in series in an input circuit (10) also contg. an electrical switch (2) in the form of a chopper transistor periodically driven by the multivibrator (4). The chopper transistor may be a MOSFET with its drain-source path connected in series with the input circuit and its gate driven by the output of the multivibrator via a NAND gate. A FET voltage stabilising circuit (5) may be connected in parallel with the input circuit.