DC DC 24V to 12V Converter Ciruit 400W SG3524 IR2111

DCDC Converter circuit is based on sg3524 pwm control integrated circuit, integrated outputs are powered by ir2111 driver integrated circuit, it reduces 24 volt input voltage to 12 volts, output power is quite high 400w 20 amps. The circuit shows ca3524 but they are all the same: sg3524, kia3524, ka3524, uc3524

FEATURES

Output current: 20A at 12V (15A continuous and 30A instantaneous)
Input voltage: between 18 and 30V DC
Output voltage: between 5 and 20V
Operating frequency: 70kHz
Efficiency: 95%
Maximum power 400W

The circuit is designed to have the highest possible performance with current and quality components, but at the same time to be as simple as possible and to be used in different applications such as solar installations or voltage reduction in 24V vehicles. The circuit starts with the 24V DC supply on connector CN1, CN2 and with diode D1, D1 is a protection against carelessness caused by polarity reversal. This is followed by a 7812 type regulator, which provides a constant voltage of +12V to power the IR2111 driver and the PWM and temperature control modules.

The power stage is built around a driver for the MOS-FET IR2111, this component contains everything needed to drive and control in HALF BRIDGE mode the power MOS-FETs. The PWM signal of the module enters via pin (2) of IC1 through two diodes that mix the two signals of the outputs S1, S2 and the compensation resistor R3, the resulting signal is a square wave with a fixed frequency of 70KHz modulated in it.

This square wave signal, amplified by the power stage T1, T2, T3 with a width of 0% to a maximum of 98% depending on the +12V output voltage, is filtered by the L2 inductance formed by a high-value AL type ferrite core toroidal, this type is very often used in switching type power supplies to filter the output voltages and eliminate as much as possible the HF (high frequency) component of the continuous voltage of the fountain output.

After L2 the voltage is rectified by a group of high-performance type diodes D10, D11. According to Schottky these diodes are characterized by their low internal resistance and high operating frequency, which makes them suitable for switching power supply applications. Finally, it is filtered and stabilized by two electrolytic capacitors C10, C11. The result is a quality power supply with very stable DC voltage.

Project of the circuit diagram and PCB photos shared resource: http://www.soloelectronica.net/de_24v_a_12v_400w.htm