East Shi IDS-2000F STB switching power supply circuit East Shi IDS -2000F STB switching power supply circuit mainly by the AC input circuit, switching oscillation circuit, outp
ut circuit and a secondary steady pressure control circuit and the like, as shown in Figure 2. 63. (1) AC input circuit AC input circuit is a switch S, fuse Fl, mutual inductance filter cl, LF1 and bridge rectifier circuit (VDI-VD4) and the like, its function is to filter the AC 220V input voltage and interference rectifier into a DC voltage of 300V, C2 to the smoothing capacitor. (2) switch and oscillation control circuit switches and the oscillation control circuit are integrated in Ul TEA1523P among the 30V DC via the switch of the primary winding of the transformer Ti O ~ to Ul foot power switch is integrated in Ul among the positive feedback winding ~ feet U1 provides power and positive feedback voltage to Ul access switch oscillation state. (3) secondary output circuit switching transformer Ti attack multiple sets of output level, the rectifier output +5 V, + 21 V, + 3V and +3.V voltages. (4) regulator circuit voltage regulator circuit connected to the output of + 5V, Rl4, R11 constitute a voltage divider circuit, U3 to error detection and error amplifier, it will error signal by the photoelectric coupling of feedback to Ul feet, of Ul oscillation output controlled.