Switch mode power supply teaching experiment

Switch mode power supplies are widely used in electronic equipment today. Our students needed to be able to study such power supplies in a laboratory environment. Commercial switch mode power supplies were ruled out because of the high voltages used and the ease with which they are damaged in unskilled hands. A number of teaching equipment suppliers were approached, however no suitable equipment was available for purchase, so our own teaching experiment was made at The University of Glasgow for student use. The equipment devised demonstrates the operation of buck, boost, inverting and flyback switch mode power supplies. The student is able to safely observe the currents and voltages around the major components and verify the basic operating equations relating input voltage and current to output voltage and current as the operating duty cycle is changed. The power supply under observation is unaffected by the connection of test equipment and is sufficiently robust for student use.