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目前,录像机的电源大多数使用开关电源,它能在电网电压110V～220V之间正常工作,电源的适应性极强。一、录像机开关电源电路松下 NV-L15型录像机电源原理图见本刊1990年第9期。(一)电路起振过程振荡电路见图1所示。280V 直流电压经开关变压器T_(1101)P_1-P_2绕组加到 IC_(1101)脚③内开关管Q_1集电极,提供集电极电压。此电压经R_(1102)、R_(1103)、R_(1123)、R_(1124)分压,从中点取出,再经起动电容C_(1109)向IC_(1101)脚②内开关管基极供电,C_(1109)的充电使Q_1很
At present, most of the power of video recorders use the switching power supply, which can work normally between 110V and 220V of the power grid voltage, and the power adaptability is extremely strong. First, the VCR switching power supply circuit Panasonic NV-L15-type VTR power supply schematic see the ninth issue in 1990. (A) circuit start-up oscillation circuit shown in Figure 1. 280V DC voltage through the switch transformer T_ (1101) P_1-P_2 winding added to the IC_ (1101) pin ③ switch Q_1 collector, providing the collector voltage. The voltage is divided by R_ (1102), R_ (1103), R_ (1123) and R_ (1124), taken out from the midpoint, and then supplied to the base of the switch of IC_ (1101) via the starting capacitor C_ (1109) , C_ (1109) charge makes Q_1 very