White noise electronic hypnotist

This electronic hypnotist is made by utilizing the calming and tranquilizing effect of white noise, and its effect is better than the monotonous raindrop sound hypnotist.

What is white noise? White noise is a way of describing sound by using the color of light. White light is a mixture of various colors of light in a certain proportion. If you use a prism to refract white light, you will get monochromatic light of various colors. Like white light, white noise is also a mixture of multiple single-frequency noises, and its energy distribution is continuous and uniform. Figure 1 is a spectrum of white noise, which shows that it contains all audible noises of all frequencies.

Figure 1 White noise spectrum

The circuit of the white noise hypnotist is shown in Figure 2. After the power is turned on, the current charges the capacitor C through the resistor R1. VT1 acts as a voltage regulator. The noise current (generated by the irregular movement of electrons) generated inside it is amplified by the transistor VT2 and then output by the earphone BE, emitting a soft "hissing" sound that can induce people to fall asleep.

Figure 2 White noise electronic hypnotist circuit

Component Selection:

VT1 is a 3DK2 switching transistor, with the collector suspended. After testing, other transistors or voltage-stabilizing diodes are not as good as 3DK2. VT2 uses 3DK4 or 3DG12 silicon NPN transistors, with a magnification greater than 150. LED uses a red ordinary light-emitting diode, which is used as a power indicator.

R1 and R2 are small carbon film resistors, C is a 16V electrolytic capacitor, and BE is an 8 ohm low-resistance earplug. The power supply voltage can be selected between 9V and 15V, and stacked batteries can be used to reduce the size.

When using, place the earplugs BE next to the pillow, and the soft noise will induce you to fall asleep. Note that the noise power of this machine is sufficient and cannot be increased, otherwise the noise will be too loud and lose its softness and hypnotic effect.