When the lamp needs to be triac dimmer by the thyristor signal, the input voltage waveform in the circuit deviates from the sine wave due to the change of the thyristor conduction angle, which also changes the effective value of the input voltage, and realizes triac dimming led driver by changing the voltage.

However, what matters here is that during the thyristor conduction process, a switch in the thyristor potentiometer can adjust the voltage divider ratio of the internal resistance, change its conduction angle, and change the effective value of the output voltage, thus Realize contant voltage triac dimming function.

Thyristor dimming technology has a long history of development, mature and stable technology, and has been perfectly combined with incandescent lamps and halogen lamps, occupying a large dimming market. Using thyristor dimming technology, it is relatively simple to match the installation and use, and only need to replace the led lamps. Thyristor dimmers are widely used in traditional lighting markets such as incandescent lamps. They are in line with people's usage habits, The dimming cost is low, and the built-in circuit is also compatible with the triac LED power supply, and there are no redundant defects.