Homemade quick hand dryer circuit

45. After washing your hands with the homemade quick hand dryer, put your hands under the quick hand dryer, and hot air will automatically blow out. After drying your hands, take your hands away and it will automatically turn off. The circuit is shown in Figure 2. When there is light, pin 1 of the IC is at high potential, TWH8751 is cut off, J is powered off, and J1-1 is disconnected. When the hand is inserted to block the light, D2 shows a large resistance, pin 2 of the IC is at low potential, the IC output terminal is turned on, J1-1 is turned on, the heating wire and motor are energized, and hot air is blown out. The power supply of the control circuit is obtained by a 36K resistor and a 2CP12 step-down rectifier to obtain a voltage of about +18V. The electric heating wire is 1KW and is spirally coiled under the motor. The main dimensions of the quick hand dryer shell and the arrangement of components are shown in Figure 1.