1, input circuit: LED drivers usually use alternating current as input power, need to convert alternating current to direct current through the rectifier circuit. A rectifier circuit usually consists of a diode or bridge that converts alternating current to direct current.
2, switch controller: Switch controller is one of the core components in the LED driver, used to control the switching state of the LED. The switching controller usually adopts PWM (pulse width modulation) or PWM (pulse width modulation) technology to adjust the brightness of the LED by controlling the on-off and off-time of the switching tube.
3, inductor: Inductor is one of the important components in the LED driver, used to store energy and release energy when needed. Inductors are usually composed of coils and magnetic cores, and their inductance value and current capacity can be adjusted as needed.
4, switching components: The switching components in the LED driver usually use MOSFET (metal oxide semiconductor field effect transistor) or IGBT (insulated gate bipolar transistor) and other switching components to control the switching state of the LED.
5, feedback resistance: Feedback resistance is one of the important components in the LED driver, used to feedback the output current back to the control circuit to achieve accurate current control.
6, output filter: The output filter is one of the important components in the LED driver, used to filter out PWM control signals and other noise to maintain the stability of the output.
In addition to the above components, LED drivers also need to design and configure other components according to actual needs, such as protection circuits, control circuits, temperature sensors, etc.
Different types of power supplies require different types and quantities of components. Taking the common low-power isolated step-down circuit as an example, the required devices are: capacitors, resistors, inductors, diodes, audiodes, field-effect transistors, transformers, photocouplers, integrated circuits. In each device type, the shape and function are also different, for example, the resistance is divided into pressure sensitive type, positive (negative) temperature coefficient type, power type, adjustable type, in-line or patch type and so on.
The input of the LED driver includes high voltage power frequency AC (i.e. city power), low voltage DC, high voltage DC, low voltage DC and high frequency AC (such as the output of electronic transformers).
The output of the LED driver power supply is mostly a constant current source, which can change the voltage with the change of the LED forward voltage drop. The core components of LED power supply include switching controller, inductor, switching element (MOSFET), feedback resistor, input filter, output filter, etc. According to the requirements of different occasions, there must be input overvoltage protection circuit, input undervoltage protection circuit, LED open circuit protection, overcurrent protection circuit.
General LED driver power supply is switching power supply, by rectifier circuit, EMC circuit, PFC circuit, sampling circuit and so on. Important components are transformers, power supply constant current chip, safety capacitor and other components
The control chip can be a single chip microcomputer, a clock circuit, or some other logic circuit, and an oscillation circuit with separate components can also be used, mainly to control the flashing logic and frequency.
This will use capacitors, resistors, transistors and other devices, if the led power is small, then directly connected on the line, if the power is large, then it is necessary to add the driver tube, can be transistor, can also make mos tube.
That's pretty much it.
The driver is a switching circuit of AC to DC, including controller, inductor, high-power FET, tripole, feedback resistor, filter capacitor, diode, input filter, various resistors, capacitors and so on. The main circuit of the LED lamp is a constant current circuit, so the light is very stable.