Thyristor dimming has been applied to incandescent lamps and energy-saving lamps dimming methods earlier, which is also the most widely applied dimming method for LED at present. Controllable Silicon dimming is a kind of dimming with physical properties, starting from AC phase 0, input voltage chopping, until the controllable silicon is turned on, there is voltage input. Its working principle is to generate a tangential output voltage waveform after passing the waveform of the input voltage through the tangential tangent wave. Applying tangential principle can reduce the effective value of output voltage to reduce the power of ordinary load (resistance load). Silicon controlled rectifier optical modulator has the advantages of high adjustment precision, high efficiency, small volume, light weight, easy remote operation and so on, and occupies a dominant position in the market. The advantages of controllable Silicon dimming lie in high working efficiency, stable performance and low dimming cost.

II. LED 0/1-10v dimming and resistance dimming

0-10v dimming is also called 0-10V signal dimming, which is a analog dimming method.
What distinguishes it from the controllable Silicon dimming power supply is that a set of interfaces (+10V and -0v) of 0-10V are added to the power supply. It controls the output current of the power supply by changing the voltage of 0-10V to achieve dimming. It is brightest at 10V, and off at 0V. However, 1-10V is only 1-10V for the dimmer. When the resistive dimmer is adjusted to the minimum 1V, the output current is 10%. If the output current is 100% at 10V, the brightness will also be 100%. It is worth noting and the best distinction is that 1-10V does not have the function of switch, and the lamp cannot be turned off to the lowest level. It can only be dimmed, but cannot be turned off, because the dimming signal still has voltage. And 0-10V has the switch function.
Resistor dimming is also called resistor dimming, which is a kind of analog dimming mode to change the voltage of dimming signal by changing the resistor resistance value.

3. PWM dimming

LED lighting, etc. By controlling analog circuits in a digital way, the cost and power consumption of the system can be greatly reduced.In addition, many microcontrollers and DSP have already included PWM controllers on the chip, which makes the realization of digital control easier. This method is based on the characteristic that human eyes are not sensitive enough to brightness flicker, making the LED light and dark. If the frequency of brightness exceeds 100Hz, what people see is the average brightness, not the LED flickering. PWM adjusts the brightness by adjusting the time ratio of light and dark. In a PWM cycle, the perceived brightness is a cumulative process because the human eye flickers to the light within 100Hz, that is, the larger the proportion of light time in the whole cycle, the brighter the human eye feels.In short, PWM is a digital coding method for analog signal levels. Through the use of high-resolution counter, the duty cycle of square wave is modulated to encode the level of a specific analog signal. The PWM signal is still digital, because at any given moment, full amplitude DC power supply is either completely available or completely unavailable. The voltage or current source is added to the analog load as a on or off repetitive pulse sequence. When the power is on, it is the time when the DC power supply is added to the load; When the power is off, it is the time when the power supply is disconnected. As long as the bandwidth is sufficient, any analog value can be encoded using PWM.