Fully automatic hand washing machine composed of SM9576

    Abstract: SM9576 is a reliable monolithic infrared sensor. It has stable performance and high reliability, and can be widely used in infrared remote control and other fields. This article introduces the actual circuit and design method of a fully automatic hand washing machine made of a single-chip infrared sensing control integrated circuit SM9576.

    Keywords: Fully automatic hand sanitizer soap supply valve water supply valve hair dryer SM9576

1 Overview

SM9576 is a reliable monolithic infrared sensor. This article introduces the actual circuit and design method of a fully automatic hand washing machine composed of SM9576. The handwasher can realize fully automatic control of soap supply, tap water supply and hand dryer. It is an ideal handwashing device for hotels, hotels and home restrooms.

2 Working principle

The actual circuit of the fully automatic hand washing machine is shown in Figure 1. The 220V AC power supply is stepped down by transformer T, bridge rectified by V1~V4, and filtered by C1 to become 9V DC power supply. This power supply supplies relays K1~K3 as the working power supply all the way, and is stabilized by the three-terminal voltage regulator 7231 all the way. Provide 3V DC power to SM9576 as working power supply. The core device of the hand washing machine circuit is SM9576, which contains an infrared transmitter drive circuit and an infrared receiver amplification circuit. Its receiving sensitivity is determined by the capacity. When C7 changes between 0.01~0.1μF, the receiving distance can be between 5~ Varies between 25cm. This circuit takes C7 as 0.1μF, and the maximum receiving distance is 25cm. SM9576 has three sets of control output terminals Q0~Q2, corresponding to pins 12, 7, and 8 respectively. The output status of Q0~Q2 is determined by the potential connected to pins 10 and 11. The output status is listed in Table 1. Pin 13 is the infrared emission output terminal. After the infrared signal output by this pin is amplified by VT1, the infrared signal is emitted outward by VD2. Pin 20 is the infrared signal input terminal. The infrared signal emitted by VD2 is received by VD1 and input through C7 and R6. to pin 20, and is amplified and shaped internally by SM9576, and finally used to control the output status of Q0~Q2.

T in this circuit uses a 220V/9V, 5W small AC transformer. VD2 and VD1 are ordinary infrared transmitting and receiving diodes respectively. VT1~VT4 are all 9013 transistors. K1~K3 can use JRX-13F, 9V small DC relays. Y1, Y2 all use 220V small AC solenoid valves, and the hand dryer can be replaced by a commercially available hair dryer.

3 Installation and debugging

Fix the handwasher above the sink, and connect Y1 and Y2 to the soap supply faucet and tap faucet respectively. The infrared transmitting tube VD2 and the infrared receiving tube VD1 should be on the same straight line, and the distance should be within 5cm. To ensure that the handwasher works reliably.