BE-150 switching power supply circuit of computer host

BE-150 switching power supply circuit of computer host

Shown is the BE-150 switching power supply circuit of the computer host , and the switching oscillation control integrated circuit is TIA94.     The AC 220 V voltage is rectified and filtered by the power switch S1, fuse, filter capacitor C21, mutual inductance filter L2 and bridge rectifier stack into 300 V DC, which provides voltage for the switching tubes VT1 and VT2. Integrated circuit TIA94 pins ⑧ and ⑤ output oscillating switching signals, which provide driving pulses to the bases of switching tubes VT1 and VI2 through transformer T2. The switching pulses are amplified by VT1 and VT2 and then added to the primary of transformer T4. The secondary of T4 is rectified and filtered. Output multiple sets of DC voltage +5 V, +12 V. Tl and I2 form a start signal when starting up, and after operation, the positive feedback winding of T2 provides a signal to maintain the oscillator.