Voice controlled delay light switch circuit (3)

It is a voice-activated delay light made with the Zile doorbell chip as the core device. When using it, just
blow a whistle or clap your palms, and the light will light up. After a delay of about 20 seconds, the light will go out on its own, which can bring more money to your
life convenient. Another feature of this circuit is that it adopts a two-wire connection method, which can directly replace an ordinary switch without
changing the original indoor wiring; it can also be connected in parallel to an ordinary light switch to transform an ordinary lighting lamp
into a sound- activated delay lamp.
    In the figure, the right part of the dotted line is the ordinary lighting circuit, and the left part is the sound delay switch. S is an ordinary light switch.
When S is closed, the lamp E
lights up, and the delay
circuit does not work at this time.
When S is turned on, the light
goes out and the delay circuit
starts to work. At this time, as long as
you clap your hands,
the light can be turned on. After a delay of 20s
, the light will go out in vain
.
    Circuit working principle: VDl--VD4 and VT4 form the main circuit of Kaige, and the control circuit is
composed of the KD-9300 music doorbell chip, microphone B, and diodes VTl-VT3. vs, e and [1s form a simple regulated power supply,
which outputs a DC voltage of about 3V for the control loop. Normally, VT2 and VT3 are cut off, the thyristor VT4 is in
the off-r state, and the light E does not light up. If you clap your palms, B picks up the sound wave signal and sends it to VT1 for amplification by (1.).
A forward pulse will appear on the collector of VTI, which will be coupled to the base of VT2 by C., causing VT2 to turn on
instantly . Music The doorbell chip works because the trigger terminal RJ(; is triggered by a high level, and the output terminals O,/P output
the music signal stored in the chip, which is injected into the gate of VT4 through the VT3 release dog, so that VT4 is triggered to turn on, and the light E When the music signal stored in the doorbell chip ends, VT3 returns to cut-off, and VT4 loses the trigger current due to the door panel
.
When
the alternating current crosses zero, it turns off and the light E goes out.
    The length of time the light of this circuit lights up depends on the length of the music signal stored in the doorbell chip. The length of
the KD-9300 integrated circuit music signal depends on the name of the stored music. Generally At about 10-20s, readers should pay attention when purchasing
. The p value of VT2 should be large, preferably below 200; VT4 should use a micro-triggered
unidirectional thyristor with a smaller trigger current, such as 2N6565 type, etc. Other elements There are no special requirements for devices.