The invention discloses a
capacitive switch safe isolation program-controlled power supply circuit. The
capacitive switch safe isolation program-controlled power supply circuit comprises a
bridge type rectifying circuit, a
single chip microcomputer, a capacitive program-controlled
voltage-reduction circuit and a switch circuit; the
bridge type rectifying circuit is composed of triodes Q1 and Q3 and diodes D2 and D3; the base electrodes of the triodes are connected with the
single chip microcomputer; the capacitive program-controlled
voltage-reduction circuit comprises capacitors C2, C3 and C4 and triodes Q4 and Q5 to form
direct current stage-by-stage
voltage reduction; the base electrodes of the triodes Q4 and Q5 are connected with the
single chip microcomputer; the switch circuit comprises two groups of program-controlled synchronous switches; the first group switches are connected with the output end of the
bridge type rectifying circuit, and the input ends of the
capacitor C2 and the
triode Q4; the second group of switches are connected with the output ends of the
capacitor C2 and the
triode Q4, and the input ends of the
capacitor C3 and the
triode Q5; and the two groups of the program-controlled synchronous switches are closed in different time. The
capacitive switch safe isolation program-controlled power supply circuit adopts the capacitive program-controlled voltage-reduction circuit instead of a cumbersome power supply
transformer, so that the factor power of the mains supply is improved and a large amount of
electric energy is saved.