Teaching oscillograph LED constant voltage constant current power supply

The utility model discloses a teaching oscillograph LED constant voltage constant current power supply, including chip U1, resistance R1, electric capacity C1, resistance R1, diode VD5, inductance L1 and transformer T, electric capacity C1 one end connect respectively VCC, electric capacity C2, resistance R2, electric capacity C4 and transformer T coil L3, the transformer T coil L3 other end connect the anodal and chip U1 pin D of diode VD6 respectively, and the electric capacity C4 other end and the resistance R2 other end are connected respectively to diode VD6 negative pole, the electric capacity C1 other end is connecting resistance R1 and inductance L1 respectively, and the electric capacity C2 other end, the inductance L1 other end, chip U1 pin S, electric capacity C3, the interior phototriode projecting pole of opto -coupler U2 and electric capacity C7 are connected respectively to the resistance R1 other end, and chip U1 pin BP is connected to the electric capacity C3 other end. The utility model discloses teaching oscillograph LED constant voltage constant current power supply adopts TNY254 control, and circuit structure is simple, and is with low costs, through constant voltage constant current mode drive LED, has promoted LED's life.