Calculation method for the number of turns of high-frequency transformers in switching power supplies
Calculation formula: N=0.4 (l/d) to the power of the root. (Among them, N is the number of turns, L is the absolute unit, luH=10 cubic meters. d is the average diameter of the coil (Cm).)
For example, when winding an inductor coil with L=0.04uH and taking the average diameter d=0.8cm, the number of turns N=3 turns. When calculating the value, the number of turns N should be slightly larger. The inductance produced in this way can be adjusted within a certain range.
The number of wires in a coil is not necessarily the number of turns. Only when the number of parallel windings is equal to 1, can the number of wires in a coil be equal to the number of turns in the coil. There is a relationship as follows: the number of wires in a coil multiplied by the number of turns wound in parallel. The number of wires in each slot of the motor stator refers to the number of turns in a single-layer winding, where the number of wires in each slot is equal to the number of turns; In a double-layer winding, the number of wires per slot is twice the number of turns, which is 2x turns.
Extended Information
1. High frequency transformers are mainly used as high-frequency switching power transformers in high-frequency switching power supplies, as well as in high-frequency inverter power supplies and high-frequency inverter welding machines. According to the working frequency, it can be divided into several levels: 10kHz -50kHz, 50kHz -100kHz, 100kHz -500kHz, 500kHz -1MHz, and above 10MHz.
2. In the design of high-frequency transformers, the leakage inductance and distributed capacitance of the transformer must be minimized, because high-frequency transformers in switching power supplies transmit high-frequency pulse square wave signals. During the transient transmission process, leakage inductance and distributed capacitance can cause surge currents and peak voltages, as well as top oscillations, resulting in increased losses.
