Note: 1. When using for the first time, please adjust the potentiometer counterclockwise to the end before powering on. Otherwise, it will be connected to the load through a small resistance heating wire. It is easy to burn the thyristor when it is powered on. 2. You must first connect the load and then adjust the voltage. 3. It is mainly used for resistive loads (electric filament incandescent lamps, etc.). Most single-phase AC motors can also be used, but there is no guarantee. Please confirm the loading capacity. 4. The fuse is not omnipotent. There is a response time. If the current is too large, in addition to burning the fuse, the module may also be burned out. 5. The plastic cover on the connector cannot be opened completely due to the housing being installed. The screwdriver must be tightened on the side. Be careful when opening. Excessive force may easily break the cover. The courier may also be damaged. This is a vulnerable part. However, it will not affect the use of the module. We are not responsible for any issues related to the plastic cover. Instructions for use: Connect this product in series to the circuit of a desk lamp or electrical appliance (that is, disconnect any one of the charged or neutral wire and the desk lamp, electrical appliance, etc., and then connect the two wires of this \"product\".) It can adjust the brightness, The function of speed adjustment, pressure adjustment and temperature adjustment; it is very convenient to use. This product is suitable for: using a new type of bidirectional -power thyristor, because the current can reach 25A, it solves the overcurrent problem caused by the electric furnace wire resistance being too small during cooling; it can easily adjust the city power supply. The output voltage of electrical appliances can be adjusted arbitrarily between 0 and 220 volts. Such as: thermal adjustment of electric stove, water heater, dimming of light, speed adjustment of small motor, temperature adjustment of electric iron, etc., so as to achieve the effects of dimming, temperature and pressure. It can be used for large electrical appliances that consume less than 2000 watts. Because the power is already large, ordinary household appliances or small factories are sufficient. (The inductive or capacitive load power should be reduced. This regulator is equipped with a bidirectional -power thyristor. The potentiometer is equipped with a nut and can be used without adding any components. Very convenient and practical). Description: The new component assembly 4 Terminals,220V into 0-220V adjustable output,Be sure to take the load transfer Mainly used:Thermostat,Dimming,Governor(Heating pipe, Heating wire ,Heating plate,Heating rods,Baisi bulb,Fan,EAF,Solder furnace,Table lamp) and so on. The regulator be suitable for 220V AC electrical , can be used to dimming, voltage regulator, thermostat, speed and other purposes. I t can also arbitrarily adjust the output voltage between 0-220V, and can be used for 4000 watts or less electrical appliances. Electrical parameters: Voltage: AC 220V Maximum power: 4000W Voltage Regulator: AC 0-220V Size:85*58*38*71mm Thyristor current: 20A(Max) Radiator: 5 thick corrugated surface aluminum radiator Resistance: Full metal film, precision power resistors Include: 1 x Speed Control Controller