How to make a voice-controlled power socket using CD4069

The voice-controlled power socket includes a power socket, a power plug and a voice-controlled circuit board. When in use, the plug of the socket is inserted into a common power socket, and then the plug of the household appliance is inserted into the power socket, and the switch of the appliance is turned on, and then the appliance can be turned on by sound (such as clapping your hands). If you want to turn off the appliance, clap your hands again, and the appliance will be turned off.

In Figure 1, D1~D4 are connected to form a bridge rectifier circuit. It and the thyristor S form the main power supply circuit of the socket CZ, D5, R1, C1 form a half-wave step-down rectifier circuit, and R3, R4, RP form a voltage divider, so that the positive terminal voltage of C1 is about 4V, which is used by the six-phase inverter CD4069. RP is a WH7 horizontal solid adjustable resistor, non-electrolytic capacitors are all CT1 ceramic capacitors, piezoelectric ceramic Y is FT-27 or HID27A-1, and the parameters of other components are shown in the figure. Except for the socket CZ and the piezoelectric ceramic Y, the rest of the components of this device can be welded on a 58mm×45mm printed board. The power socket shell can be modified from a commercially available two-hole (or three-hole) socket. The printed board should be fixed inside the socket. A dozen small holes should be drilled with an electric drill at the upper right corner or the lower right corner of the socket. These small holes should be evenly distributed within a circular range the size of a 1-yuan coin. These small holes serve as sound-transmitting windows (the sound-transmitting windows can also be dug into strips). The piezoelectric ceramic piece is fixed to the sound-transmitting hole with 502 glue. A cover with a power plug should also be installed on the back of the socket (that is, the entire voice-controlled power socket is actually a box-shaped. The appearance diagram is shown in Figure 2. After all components are installed and checked as shown in Figure 1, they can be powered on for debugging.

First, the voltage between the six inverters and the ⑦ pin should be about 4V, otherwise, check the components such as D5, R1, and C1. If the voltage is normal, you can use an insulated small screwdriver to adjust RP. Make the level of the ⑧ pin of CD4069 just change to a low level (still 4V high level at this time). At this time, blow a breath to the piezoelectric ceramic Y with your mouth, and you should be able to see that the level of the ⑧ pin drops to a low level (monitor the voltage of the ⑧ pin with a multimeter), and then restore the high level (that is, a negative pulse is output), indicating that the sensitivity has been adjusted to the highest level and can be put into trial use. In actual use, the sensitivity can be adjusted to a suitable level according to the conditions of each person's use, that is, it is not sensitive to the sound of conversation, music played by TV, tape recorder, etc., but sensitive to the sound of clapping. During the debugging process, if it is found that the voice control sensitivity is too low, it is necessary to clap loudly to make the socket work. Generally, RP is not adjusted to a suitable level or the quality of the piezoelectric ceramic is too poor. It can be readjusted or the piezoelectric ceramic can be replaced with a high-impedance headphone sound film. If you find that the light is not turned on and off by the clapping sound, but flashes alternately, it is usually because the RP resistance is too small. Just increase the resistance. After the RP is adjusted, use paint or wax to fix the adjustment screwdriver mouth, and then the voice-controlled power socket can be put into formal use.