TV Panasonic TC-2588 is the brightest in the switching power supply secondary voltage output with a perfect over-current protection circuit, when each output circuit failure , the protection circuit is activated , the oscillator circuit by optocoupler switching off the power supply into the protected status .gVrservice manual download site
    The machine has a switching power supply output voltage overvoltage protection + B , B + multiple load overcurrent protection circuit , + B load short-circuit protection , +46 V voltage load short-circuit protection and 16V voltage load short-circuit protection. The protective circuit as shown in the drawings .gVrservice manual download site

The implementation of elements of the protection circuit is Q805, when the brightest sent to protect voltage detection circuit , Q805b extremely high saturated conduction , D825 deadline , optocoupler D811 off, switching power oscillation circuit stop vibration. Its brightest protection detection circuit as follows :gVrservice manual download site

1, + B voltage protection circuit . Voltage divider circuit R850, R851 and D831 integral regulator switching power supply + B voltage protection , output switching power supply + B when the voltage is too high , the midpoint of the voltage divider circuit exceeds 10V, the regulator D831 breakdown conduction will be added to protect the actuator Q805b high pole .gVrservice manual download site

2, + B load current protection circuit . Q831 and sampling peripheral components such as resistors R834/R835 + B load current protection circuit , when the + B load flow, voltage drop on R834/R835 increased when higher than 0.7V, Q831 is turned on , its c extremely high, through R831, D832 makes the implementation of circuit protection Q805 conduction.gVrservice manual download site

3, + B load short-circuit protection circuit. + B when the load short circuit, the negative short-circuit to ground D830 , D830 conduction, the D825 off optocoupler D811 off into the protected status .gVrservice manual download site

4, +46 V voltage load short-circuit protection . D837 etc. +46 V voltage load short-circuit protection circuit, when the +46 V voltage load short , D837 anode shorted to ground , D837 conduction , D825 deadline , optocoupler D811 off into the protected status .

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