With the continuous development of LED technology, LED applications continue to mature, from indicator lights, signal lights, display screens, and landscape lighting to indoor and outdoor lighting. Warmly remind everyone that when using LED products, pay attention to the protection of the LED power supply and drive circuit.
Since the LED power supply and drive circuit are easily damaged by over-current shocks and short-circuit faults, protection measures for various fault states should be fully considered in the design of the drive circuit to improve the reliability of the circuit and reduce the repair rate.
Although many high-end LED driver devices have gradually integrated protection functions such as overcurrent and overheating, in many occasions, especially in terms of overheating protection, discrete component solutions are still needed as a cooperative protection solution to make the lamps more reliable and more reliable. Long life.
PPTC refers to high polymer positive temperature thermistor, which is composed of polymer and conductive particles. After special processing, the conductive particles form a chain-like conductive path in the polymer. When the normal working current passes (or the component is at normal ambient temperature), the PPTC is in a low resistance state. When there is an abnormal overcurrent in the circuit (or the ambient temperature rises), the heat generated by the large current (or the ambient temperature rises) causes the polymer to expand rapidly, cutting off the conductive path formed by the conductive particles, and the PPTC presents high resistance. state. When the overcurrent (over-temperature state) in the circuit is eliminated, the polymer cools and the volume returns to normal, the conductive particles re-constitute the conductive path, and the PPTC assumes an initial low-resistance state. PPTC is small in size, low in cost, can be used repeatedly, and realizes automatic start and automatic recovery of circuit protection.
In LED lighting, there are different overheating protection methods according to different lighting applications, usually divided into two types. One way is to immediately activate the shutdown protection when the specified temperature is reached. This protection is usually applied to road traffic lights. The other way is to start the protection at a certain temperature and drive with a reduced current. This type of protection is usually used in indoor lighting and road lighting.
Dongguan Fengzhan Electronic Technology Co., Ltd specializes in customizing LED wiring harnesses according to customer requirements. Welcome Inquiry.
Contact: Lynn Long
Phone: 0086 13640200141
Add: No. 19, Minye Street, Zhufoling Community, Tangxia Town, Dongguan City, China