A simple and easy-to-make rechargeable hypnotist

The circuit diagram of the simple charging hypnotist is shown in the figure. After the 220V AC power supply is rectified by D and limited by R1, a DC voltage of about 300V is generated at both ends of C1. After this voltage passes through the oscillation circuit composed of R2, C2, and Qce junction, a pulse current is generated to make the speaker B emit a "click, click, click..." raindrop sound. As the voltage across C1 decreases, the rhythm of the raindrop sound gradually slows down until the power of C1 is exhausted and stops.

This circuit is instantaneous charging. Press AN and hold for more than 1 second, then release AN. The circuit working time is proportional to the size of C1. In the figure, the capacity of C1 can make the oscillation circuit work for 40 minutes.

By adjusting the values ​​of R2 and C2, you can change the output frequency of the oscillation circuit, thereby changing the rhythm of the raindrop sound to achieve a hypnotic effect that suits you.