Primary sampling current controlled synchronous rectifying drive circuit

A primary winding current controlled synchronous rectifying drive circuit, comprising:

• a current sampling circuit that detects a current signal in a primary winding of a transformer and forwards it to a signal shaping and reset circuit;
• and
• a current compensation signal circuit that compensates a magnetizing current in the primary winding of the transformer;
• wherein the signal shaping and reset circuit converts a sample of the current signal into a voltage signal and shapes it into a pulse signal, and then forwards the current signal to a logic control and power drive circuit that converts the pulse signal into one or more drive signal(s) through logic control, then the drive signal(s) are amplified to drive a corresponding synchronous rectifier;
• wherein the current sampling circuit is connected in series with a Hall sensor (HL) of the primary winding (P) of the transformer;
• and
• wherein the compensation signal circuit comprises a thirteenth resistor (R13), a fourteenth resistor (R14), a fifteenth resistor (R15), a capacitor (C1) and an integrated operational amplifier (IC1), with an end of the thirteenth resistor (R13) is connected to a dotted terminal of a secondary winding (S) of the transformer while another end of the thirteenth resistor (R13) is connected to an end of the fourteenth resistor (R14), to an end of the capacitor (C1) and to a negative input terminal of the integrated operational amplifier (IC1);
• and a positive input terminal of (IC1) is connected to the other end of the fourteenth resistor (R14) and an end of the fifteenth resistor (R15);
• and another end of the fifteenth resistor (R15) is connected to the non-dotted terminal of the secondary winding (S) of the transformer, and the capacitor (C1) is connected to an output terminal of the integrated operational amplifier (IC1).

A primary winding current controlled synchronous rectifying drive circuit, comprising:

• a current sampling circuit that detects a current signal in a primary winding of a transformer (S) and forwards it to a signal shaping and reset circuit;
• and
• a current compensation signal circuit that compensates a magnetizing current in the primary winding of the transformer;
• wherein the signal shaping and reset circuit converts a sample of the current signal into a voltage signal and shapes it into a pulse signal, and then forwards the current signal to a logic control and power drive circuit that converts the pulse signal into one or more drive signal(s) through logic control, then the drive signal(s) are amplified to drive a corresponding synchronous rectifier;
• wherein the current sampling circuit comprises a current transducer (ST), which comprises a primary sampling winding (N1) for detecting the current signal in the primary winding of the transformer, a compensation winding (N2), and a secondary output winding (N4);
• wherein the current compensation signal circuit comprises the inductor (L1);
• and
• wherein the inductor (L1) is connected in series with the compensation winding (N2) of the current transducer (ST) and is connected in parallel with any two terminal of a secondary winding (S) of the transformer.

A primary winding current controlled synchronous rectifying drive circuit, comprising:

• a current sampling circuit that detects a current signal in a primary winding of a transformer and forwards it to a signal shaping and reset circuit;
• and
• a current compensation signal circuit that compensates a magnetizing current in the primary winding of the transformer;
• wherein the signal shaping and reset circuit converts a sample of the current signal into a voltage signal and shapes it into a pulse signal, and then forwards the current signal to a logic control and power drive circuit that converts the pulse signal into one or more drive signal(s) through logic control, then the drive signal(s) are amplified to drive a corresponding synchronous rectifier;
• wherein the current sampling circuit is connected in series with a Hall sensor (HL) of the primary winding (P) of the transformer;
• and
• wherein the compensation signal circuit comprises a thirteenth resistor (R13), a fourteenth resistor (R14), a fifteenth resistor (R15), a capacitor (C1) and an integrated operational amplifier (IC1), with an end of the thirteenth resistor (R13) is connected to a dotted terminal of a secondary winding (S) of the transformer while another end of the thirteenth resistor (R13) is connected to an end of the fourteenth resistor (R14), to an end of the capacitor (C1) and to a negative input terminal of the integrated operational amplifier (IC1);
• and a positive input terminal of (IC1) is connected to the other end of the fourteenth resistor (R14) and an end of the fifteenth resistor (R15);
• and another end of the fifteenth resistor (R15) is connected to the non-dotted terminal of the secondary winding (S) of the transformer, and the capacitor (C1) is connected to an output terminal of the integrated operational amplifier (IC1).