US 5,331,127 AGranted

Dual push-pull induction heating drive circuit

OwnerSu-Min Cheninventor

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Abstract

A dual push-pull induction heating drive circuit comprises an oscillation triggering control circuit regulating the ON-OFF switch of the circuit activation, a switching logic circuit bringing about two exclusive pulse signals serving to drive via an amplifying circuit a dual push-pull switching output circuit having two power elements connected to an induction coil, a pulse width modulating circuit having a controlled comparing element capable of sending out adjustable pulse, and a synchronous detection comparing circuit having at least a comparing element and having an input end in communication with an induction coil and another input end connected with a power source and further having an output end connecting with the switching logic circuit and sending out synchronous pulse signals to a differentiation circuit to bring about synchronous differentiation pulse signals, which are received by the pulse width modulating circuit so as to generate the power control pulse signals serving via the switching logic circuit and the amplifying circuit to drive alternately the two power elements so as to cause the induction coil to bring about high frequency oscillation.

Claims6

Dependent claims

A dual push-pull induction heating drive circuit comprising:

an oscillation triggering control circuit, connected by means of a signal line with a switching logic circuit which sends out two oscillation signals that pass through an amplifying drive circuit and drive a dual push-pull switching output circuit provided with at least two power elements connected with an induction coil;
and
a pulse width modulating circuit having a comparing element controlled to send out pulses with widths capable of being modulated, said pulses serving via said switching logic circuit and said amplifying drive circuit to drive alternately said power elements to cause said induction coil to generate an alternating magnetic field, and
wherein a synchronous detection comparing circuit having at least a comparing element is provided with two input ends thereof connected respectively with two ends of said induction coil, said comparing element having an output end sending out a synchronous pulse signal received by said switching logic circuit and a differentiation circuit to bring synchronous differentiation pulse signal received by an input end of said comparing element of said pulse width modulating circuit to generate power control pulse signal intended to drive alternately said two power elements via said switching logic circuit and said amplifying circuit to cause said induction coil to bring about high frequency oscillation.

1 more element

Dependencies are inferred from the claim text.