emergency light circuit diagram
Battery charging circuit, power supply via Q2, Q6, R8, D10 constant current charging the battery. When external power supply, the charging current through R8, D10 to charge the battery, and the charging indicator light D1Figure: Fire emergency light circuit diagram 2. Light control circuit consists of Q3, still, Q5, Q7 and the key K, G constitu
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te, in the absence of electricity, K (open) keys, Q5 saturated conduction, Q5`s collector current to maintain conduction through the R12 to Q7 pass; D11 work in the reverse breakdown voltage state, Q5`s collector voltage to Q3, Q4 to provide bias to turn on, light L1, L2. When you G (off) button, Q7 off, remove the Q5 on-condition, lights off. When there is electricity supply, the external power supply cut-off by the D9 to D7, Q5 can not turn on, key K and G can not control the lights Ll, L2 of the on and off. After the negative potential of power diode D7 becomes zero, making it an instant the forward, Q5 saturated conduction, composition lighting circuit conditions, L1, L2 is lit. To a negative electric potential changes after the D7 high and cut-off, Q5 off, lights out (to play the role of automatic control). Lighting control circuit D7, Q7 work in the critical state by R6, open the key K, G has only a triggering role. 3. Test circuit when the test button press and hold when S, Ql deadline, D7 low negative potential change is partial conduction, so that to meet the lighting conditions Q5 conduction, so that L1, L2 is 4. 220V AC power supply circuit by the transformer (not shown) transformer, rectifier filter, the Ql collector output voltage of 4. 6V DC. Primarily to the charging circuit to charge the battery. And instructions by the R9 to D14 light. 5. k barrier display circuit by the D13, Q8, R17, and D11 form fault...
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