Few Switching regulator circuits

Switching regulators work by drawing small amounts of energy from the input source and transferring it step by step to the output. This task is attained by using an electronic switch (operating at a predetermined frequency) which works like a gate between the input energy source and the output. This gate controls the amount of charge that is trans
Few Switching regulator circuits - schematic

ferred to the output load. The output voltage of the switching regulator depends on how much time the switch is maintained closed. If the OFF time of switch is long then less energy will be transferred to the output load and so the average output voltage will a be low. If the OFF time of switch is short then more energy will be transferred to the output load which results in a better average output voltage. The schematic of a basic switching regulator is shown below. When switch S1 is closed capacitor Cout is charged and when switch S1 is open the Cout discharges through the load. The duty cycle of the S1 determines how much energy is transferred to the output load. In simple words the capacitor Cout serves as a filter which converts the pulse waveform from the switch in to a steady voltage. The output voltage will be always a function of the input voltage and the duty cycle of the switch. The schematic of a practical switching regulator is shown above. This circuit has two additional components, a Schottky diode D1 and an inductor L1. These two components are present in almost all switching regulator circuits and they drastically improves the performance of the circuit. Let us see how the diode and inductor improves the performance of the regulator circuit. When switch S1 is closed the inductor L1 opposes the rising current by creating an opposing electromagnetic field and this makes the diode D1 reverse biased and it...

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