LED lighting circuit diagram in refrigerator

The picture shows the circuit principle of the LED lighting in the refrigerator. The LED light in this circuit is composed of 8 white LED high-brightness light-emitting tubes. The LEDs are installed in a white transparent plastic tube. The length of the plastic tube is equal to the height of the refrigerator cabinet. The AC mains power generates a double 6V AC voltage on the secondary side of the power transformer TR through the door switch SB and the fuse FU. The diodes VD1 and VD2 perform full-wave rectification, the capacitor C1 filters, the resistor R1 limits the current, and the voltage regulator tube ZD1 smoothes the DC voltage. Stable 12V power supply is provided to the LED light strip. The forward working voltage of a single white LED is 3.1 V, and it is powered by 12V. The power of each LED is 0.06 W, and 4 LEDs are 0.25W. There are two groups in total, and the total power consumption is less than 1W. In this way, the total luminous intensity of the LED can be close to 40 lm, generating only weak heat and consuming very little power.

SB is the refrigerator door control switch. When the lighting of the refrigerator is switched to LED, the SB connection must also be changed.