Low power timer switch

As shown, the timing circuit due to the installation of the electronic switch by the F1, F2 and VT1 composed of quiescent current can be reduced to 555 l ~ 2 A. When the power

is first turned on, since the voltage on C2 can not jump, so F2 gate goes high, F1 to lock in a low output potential, VT1 off, so that the quiescent current of the entire circuit is small. When you press the timer switch AN, F1 input of a negative pulse appears, F1 output goes high, VT conduction, only the supply voltage 555. At the same time, due to the negative pulse is applied to 555 feet 2, 555 set, K Pull, the timer starts. Timing td 1.1R4C3. Timing can be changed by adjusting the length of the time constant R4C3 of.

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