The Principle Of Constant Voltage Transformers

The 3 phase constant voltage transformer transformer has an "日" (Japanese character for "day") shaped iron core. The primary coil is in one window opening, and the secondary coil and resonant coil are in the other window opening. The resonant coil is connected to an external capacitor to form a resonant circuit with a resonant frequency close to the power supply frequency.

When the primary power is switched on, the resonant circuit oscillates, causing the secondary iron core to become slightly saturated, forming a constant alternating magnetic field.  Its magnetic induction intensity remains within a certain range and is basically unaffected by changes in the input voltage. Therefore, the induced electromotive force of the secondary coil remains constant. In this case, the primary input current only serves to replenish energy.

The output voltage of the constant voltage transformer for home transformer is only related to the magnetic properties and cross-sectional area of ​​the iron core, and is independent of the turns ratio of the primary and secondary coils.

The efficiency, size, and weight of the constant voltage transformer are similar to those of ordinary transformers. When the iron core material is of good quality, the output voltage variation is less than 1.5% when the mains voltage varies between 160-250 volts; when the load current decreases from full load to half load, the output voltage variation is approximately 1.5-4%; when the output is short-circuited, the output current increases by about 1 time, so it is not afraid of prolonged short circuits.

Operating conditions for constant voltage transformers:

1. Altitude not exceeding 1000 meters, ambient temperature not higher than 40℃ and not lower than -40℃. When exceeding these normal operating conditions, the rating should be adjusted accordingly according to the national standard GB6450-86.

2. Relative air humidity not greater than 85% (at a temperature of 20℃±5℃).

3. Locations without severe vibration and shock, and with a vertical inclination not exceeding 5℃.

4. Locations free from conductive dust and corrosive gases or vapors that can damage metals and insulation.

5. Locations where there is no risk of fire or explosion.