LED controllers control every switch in LED control circuits via chip processing. With the continuous growing of LED light sources, more and more clients and end users required to use controllers. However, unlike LED lighting fixtures, LED controllers have developed only for a few years, still in the immature stage. Ordinary consumers had little knowledge on this part, plus lacking of uniform standards, many consumers had on ideal of how to choose suitable LED controllers for their LED lighting devices.
- LED controllers for low-power LED devices:
The normal working voltage of low-voltage LED devices is usually 12VDC-24VDC, normally 3-6 series in each branch, using current-limiting resistances to control the current in each branch under 20mA. Multi-branch LED lighting devices have both advantages and disadvantages. Advantages: low-voltage, simple structure, simple design; disadvantages: high current in large-scale applications, low-voltage switching power supply required. Low-voltage cannot realize long-distance transmission. Usually electronic devices with low input voltages are relatively small, like billboards, advertising signs, etc. According to this feature, controllers for small LED lighting devices have their own design specifications: 12V LED lamps are usually controlled by 75A/30V MOS power transistors. 24-36V LED devices are usually controlled by 60A/50V MOS power transistors.
- LED controllers for high-power LED devices:
High-power LED products work under 220VAC (or different AC in different countries). There are usually 36-48 LED chips connected in series in one branch. The normal working current for each branch is less than 20mA. There are two major current-limiting methods: a. current limitation though resistors. Demerit of this method is high power consumption. It is recommended that using 1/4W metal mold resistors after each four series LEDs, to dissipate the heat evenly. Currently, this is the most stable method. Another method is limiting the current via resistor-capacitor connecting in series. By doing so, most potential will drop on capacitors, low power consumption, only can be used in a stable long bright state.
- Low-voltage LED devices + DMX 512 controllers:
Many architectural and decorative led high bay light projects need to use a large number of LED lighting products. At present only DMX 512 controllers could realize multi-branch control. There are two methods: a. Achieving the purpose of control through serial signal transmission; b. Achieving the purpose of control through parallel signal; In order to avoid the drawback of serial signal chips (easily damaged), DMX 512 controllers adapt parallel connecting of their signal lines. Thus the failure of one branch has no influences on other branches.