Switching Power Supply

Switching Power Supply
One that we often encounter in electronic equipment these days are switching power supply. In addition to its small, compact and neat, it can also provide benefits that electric currents generated quite large compared to the power supply using a common iron core when considered in terms of the same dimension.

In this switching power supply transformer that is used specifically of using a switching transformer varies in size depending on the size of the strong electric current to be generated. To generate the secondary coil voltage switching tranfo This requires a special circuit in the primary coil, it aims to get the frequency of the AC voltage is very high (typically in the order above 25 KHz) as input to the primary coil switching transformer. Usually the primary circuit switching transformer is special oscillators are commonly used, namely LC oscillator or using a particular IC as osilatornya. Thus the oscillator will be used to control the transistors as switches or FET can also be used to make an input voltage pulse with a current large enough to pass the primary coil transformer switching frequency is of course the same as the frequency osilatornya earlier. One thing that must be noted that for mengasilkan pulse and switching the input voltage to the transformer, the input voltage derived from AC 220 Volt / 50 Hz DC voltage must be rectified first by using a diode and capacitor filter (polar / electrolytes), and if necessary, coupled with the inductor, resistor and capacitor nonpolar great power to adjust the electrical current to be passed to the primary coil transformer switcing. Diodes and capacitors to be used for the rectifier must have values ​​that are tailored to the voltage source that is not easily damaged and are required to view the datasheet for the diode. To use a small current diode IN4007 can be used and if you need larger currents can be used diode IN5408, BY 228, and the like. While on kapsitor filter must use a minimum working voltage of 400 volts DC and note the correct polarity.

Picture diode rectifier for switching power supply circuit

BY-228 type