12V electronic transformer circuit diagram principle

　The working principle of the electronic transformer is similar to that of the switching power supply. The VD1～VD4 converts the commercial power into DC, and then converts the DC into a high-frequency current of several tens of kilohertz, and then uses a ferrite transformer to step down the high-frequency and high-voltage pulses. When the electronic transformer is working normally, the working voltage at point A is about 215V, the point B is about 108V, the point C is about 10V, and the point D is 25V. If it does not oscillate, check if the phase of VT1, VT2 and L1, L2, L3 is normal. Changing the number of turns of L5 changes the output high frequency voltage.
　Component serial number parameters: R1/1Ω/1WR2/200K, C1=0.01/100V, C2C3/0.47/250V, C4C5/1000P/1KV. VT1VT2/C3039L1L2/6T, L3/1T power electronic transformer is a kind of basic function that combines power electronic converter (rectifier, inverter) and high frequency transformer to realize electric energy conversion, energy transmission and system isolation of traditional power transformer. Transmission and distribution equipment.
　Since power devices currently applied to power systems are lower in terms of capacity and withstand voltage than transmission systems, it is expected that power electronic transformers should be implemented in the power distribution field in the future. The power electronic converter (rectifier, inverter) of the power electronic transformer should consist of two parts: the main circuit and the control circuit. For the transformer of the power distribution system, in order to be consistent with the conventional power transformer, the power electronic converter connected to the power supply side and the corresponding winding of the corresponding high frequency transformer are defined as the primary side; the power electronic converter connected to the load side And the corresponding winding of the corresponding high frequency transformer is defined as the secondary side. Between the two The high frequency transformer is connected.
　The working principle is: on the primary side, the high frequency of the power frequency busbar becomes a high-frequency alternating wave through the action of the power electronic converter, that is, the frequency of the voltage is increased on the primary side to achieve the effect of frequency up-conversion. Since the volume of the transformer is related to the saturation flux density of the core material and the maximum allowable temperature rise of the winding, the transformer having a large saturation magnetic flux density is also large. The saturation flux density of the core material is inversely proportional to the operating frequency of the transformer. Therefore, the up-regulation of the primary-side power electronic converter can improve the utilization of the core material, thereby reducing the volume of the transformer and saving the transformer. space. This is also a major advantage of power electronic transformers compared to traditional power transformers.