NON-ISOLATED SWITCHED POWER SUPPLY FOR HIGH VOLTAGE LED STRIP

摘要

A non-isolated switched power supply for a high voltage LED strip comprises: a full-bridge rectifier circuit (10), a switch Q2, an electrolytic capacitor C2, an energy storage inductor L1, a diode D4, and a PWM circuit (90). A PWM signal output terminal of the PWM circuit (90) is connected to a control electrode of the switch Q2. The switch Q2 and the diode D4 are connected in series between two output terminals of the full-bridge rectifier circuit (10), and a negative terminal of the diode D4 is connected to the positive output terminal +VCC of the full-bridge rectifier circuit (10). The energy storage inductor L1 is connected between a negative terminal of the electrolytic capacitor C2 and a positive terminal of the diode D4. The non-isolated switched power supply uses a new circuit structure and modulates the voltage of the energy storage inductor L1 to be maintained at 130 V via the pulse width of the PWM circuit (90), such that the electrolytic capacitor C1 can always output a high voltage of 180 V, and the cost of the power supply is low, which can make a high voltage LED strip manufacturer more competitive.