When power source closes, the charge on C1 of filter wave capacitance begins to discharge. Because the negative charge of 7805 is smaller than the bear of 7812 much, the charge on C1 is released from 7805 a side entirely almost, its result, a dot voltage and the voltage that 7805 output carry B to nod drop quickly; And on the other hand, 7812 output carry C to because C3 discharge is slow,hint tension, in A drop voltage drop arrives after 0v, c nods voltage to still have leftover voltage. To 3 end manostat, output carries voltage prep above to input end, with respect to dynatron of power of meeting attaint interior.

To avoid dynatron of attaint interior power, can be between output end and input end retrorse bond the rectification diode of a 1A (2) seeing a picture. Below electrify condition, because diode slants instead, do not affect 3 end manostat works; After cutting off the power, electric current can input end through diode flow direction. Avoid retrorse voltage to be opposite of internal power dynatron damage.
Additional. When with 3 end manostat receives constant current source to charge to batteries, also need to output end to string together in its receive a diode (3) seeing a picture, voltage of the accumulator when cutting off the power in order to prevent damages 3 end manostat.

Graph 4 it is the 3 internal composition block diagram that carry manostat. Input the collector join of end and internal power dynatron, and output end and blast off extremely join. When output electric pressure ratio is inputted when voltage is tall, the Vcf of power transistor and Vbe are added retrorse voltage. Because the retrorse compression of power transistor counts volt only. Very easy by puncture.

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