The working principle of LED open circuit protector

In recent years, the use of 1 ~ 3 w high power LED lamps and lanterns is increasing year by year, it can range from several to hundreds of watts. The structure of the high power LED lamps and lanterns USES LED series, with constant current power supply, its structure is shown in figure 1. General 1 wled working current is 250 ~ 350 ma, 3 wled working current is 600 ~ 700 ma, current up to 900 ~ 1000 ma.

this figure 1 LED drive circuit in series of LED lamps and lanterns has a drawback, if one of the series of LED LED open circuit, the entire lamp is not lit up. This for some lamps and lanterns ( Such as warning lights, miner's lamp, emergency lights, etc. ) The application is very dangerous. When open, in order to prevent the LED light, LED lights can, the use of the LED open circuit protector is effective, it can guarantee the safety of the use of lamps and lanterns.

1 wled open protector has developed two kinds of structure: the zener diode type and brake pipe type ( One-way thyristor type) As shown in figure 2. Some LED manufacturers directly to the zener diode with LED encapsulation, namely the LED with open circuit protection are also listed. 3 wled working current of the general values of 700 ~ 1000 ma, the open circuit protector in the market because of its high current is rare.

figure 2 two leds protection device