1. Fuse (tube) is used to protect the LED drive power supply

Since the fuse is one-time, slow in response, poor in effect, and troublesome to use, the fuse is not suitable for use in finished LED lights, because LED lights are now mainly used in urban glory projects and lighting projects. It requires the LED protection circuit to be very strict: when the current exceeds the normal use current, the protection can be started immediately, so that the power supply path of the LED is disconnected, so that both the LED light and the power supply can be protected, and the power supply can be automatically restored after the entire light is normal. , does not affect the LED work.

2. LED drive power supply uses transient voltage suppression diodes

Transient Voltage Suppression Diodes are high performance protection devices in the form of diodes. When its two poles are impacted by reverse transient high energy, it can immediately reduce the high resistance between its two poles to low resistance at a speed of 10 to the minus 12 second power in a very short time, absorbing up to several kilowatts of surge power , the voltage clamping element between the two poles is at a predetermined voltage value, which effectively protects the precision components in the electronic circuit. Transient voltage suppression diodes have the advantages of fast response time, high transient power, low leakage current, good consistency of breakdown voltage deviation, easier control of clamping element voltage, no damage limit, and small size.

However, it is not easy to find TVS devices that meet the required voltage value in actual use. The damage of the LED light beads is mainly caused by the overheating of the inside of the chip due to excessive current. TVS can only detect overvoltage but not overcurrent. It is difficult to master the selection of the appropriate voltage protection point, and the device cannot be produced, so it is difficult to use it in practice. Selecting the right TVS device requires some technical experience.

3. LED drive power select resettable fuse

The resettable fuse, also known as the polymer positive temperature thermistor PTC, is composed of polymer and conductive particles. When the normal operating current passes (or the component is at normal ambient temperature), the PTC resettable fuse is in a low resistance state; when there is an abnormal overcurrent in the circuit (or the ambient temperature rises), the high current (or the ambient temperature rises) The generated heat causes the polymer to expand rapidly, which cuts off the conductive path formed by the conductive particles, and the PTC self-recovery fuse is in a high resistance state; in the normal working state, the self-recovery fuse generates little heat, and in abnormal working state its heat is very small. If the heat generation is very high, the resistance value is very large, which limits the current passing through it, thus protecting the LED driving power supply.