A switching power supply is a device transforming the voltage from one level to another. A switching-mode power supply (SMPS) is a power supply that provides the power supply function through low loss components such as capacitors, inductors, and transformers and the use of switches that are in one of two states, on or off. The advantage is that the switch dissipates very little power in either of these two states and power conversion can be accomplished with minimal power loss, which equates to high efficiency. Usually a switching-mode power supply is circuit that operates in a closed loop system to regulate the power supply output.

The switching mode power supply contains a transformer/coil and to make this as small as possible, the internal switching frequency has to be quite high, something typically in the range between 20KHz and 1MHz. This also makes the device noiseless to human ears. The oscillator noise is often conducted onto the input and output lines with a frequency that varies with the load.

This trainer consists of fundamental blocks like multivibrator, pulse width modulator, control voltage feedback, MOSFET power devices etc. This operates at 60KHZ. This trainer essentially demonstrates how SMPS works. The scope of this trainer provides necessary test points for observation of the above referred signals for study.

Specifications:

• Operates on principle of PWM
• Duty cycle: 85%
• Output: 5V @ 1A
• Input: Unregulated at 10V
• Oscillator : 60KHz
• Voltage feedback circuit to determine PWM duty cycle.