LED open circuit protector

These devices are specially designed to keep the rest of the series LED lamp string still functioning in the event of a LED failure. They are compact silicon based devices mounted on each LED terminal. As a bypass device, they are able to send current along the path around the open circuit LED, keeping the rest of the LED string still capable of lighting. Some LED open circuit protection devices also provide ESD / lighting and reverse polarity protection, which can reduce the cost of lighting circuits, eliminating the need for additional protection components.

LED open circuit protector operation

The LED open circuit protector is the two terminal device that is installed on the LED, and if the LED itself is repaired or replaced, it will automatically reset. This protector is a voltage triggered switch, low leakage, and a similar switch, when it is triggered (Figure 1), it becomes a low impedance switch, can minimize power consumption. The channel status of the LED is decreased by about 0.7V, which is not enough to open the protector device. Once a LED fails to form an open circuit, there is sufficient circuit voltage to trigger the protector to the channel state (constant current output voltage supplied by the LED drive circuit). The PLED6 series described in Figure 3 is also built with an anti surge feature that helps protect the LED from near lightning or electrostatic discharge events.

Figure 1: typical LED open circuit protector

V-I features.