In recent years, lamps made with 1 to 3W high-power LEDs have increased year by year, and their power can range from a few watts to hundreds of watts. High-power LED lamps adopt the structure of LED series connection, and are powered by constant current. The structure is shown in Figure 1. Generally, the operating current of a 1W LED is 250-350 mA, the operating current of a 3W LED is 600-700 mA, and the current is 900-1000 mA.
Figure 1: LED driver circuit
Such a series LED lamp has a disadvantage that if one of the LEDs in series is open, the entire lamp is not illuminated. This is very dangerous for the application of certain lamps (such as warning lights, miner's lamps, emergency lights, etc.). In order to prevent the LED light from being bright when the LED is open, it is very effective to use the LED open circuit protector, which can ensure the safety of the lamp.
The 1W LED open circuit protector that has been developed has two structures: Zener diode type and thyristor type (one-way thyristor type), as shown in Figure 2. Some LED manufacturers directly package Zener diodes with LEDs , that is, LEDs with open circuit protection are also available. The operating current of the 3W LED is generally 700 to 1000 mA. This open circuit protector is still rare in the market due to the large current.
Figure 2: Two LED Protection Devices
This article will introduce the new device NUD4700 launched by ON Semiconductor in January 2009 and the SMD602 introduced by SMD in 2008. They are all thyristor type LED open circuit protectors.
DC Planetary Gear Motor including a dc motor and planetary gearbox. The most important character for Dc Planetary Gear Motor is the high efficiency as much as 90%.
In a planetary gearbox, the gears integrated with each other just like the planet in the universal, the gears bit each other tightly in order. This is why the dc Planetary Gear Motor with such high efficiency. Certainly the price for planetary would be twice or more than spur.
On the other hand, if related projects have strict requirements about cycle or working life, for example electronic lock has special request about cycle test, so planetary gearbox with carbon brush motor would be first recommendation.
According to the size of gearbox, the normally dc Planetary Gear motor including 16mm, 22mm, 28mm, 36mm and 42Mm Dc Planetary Gear Motor.
DC planetary gear motor are mostly applied on robots and some products with high torque.
DC Planetary Gear Motor
Dc Planetary Gear Motor,Brushless Dc Motor,Planetary Gear,Planetary Gear Motor
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