Drinking driving automatic protection circuit diagram

Single chip microcomputer STM32L151CCU6

Crystal oscillator

Photocoupler

In traffic accidents, traffic accidents caused by drunk driving account for a considerable proportion. To prevent drunk driving, we need to install a drunk driving automatic protection device in the car. The total consists of four parts, as follows:
Detection circuit: The detection circuit is divided into two parts. The first part is the alcohol gas detection circuit. It uses the characteristic of alcohol sensor to have high sensitivity to alcohol to detect the alcohol content in the air. The structure diagram is shown in Figure 2.
The alcohol sensor is a tin dioxide semiconductor type alcohol gas sensor which has high sensitivity to alcohol and fast response characteristics. However, its disadvantage is that due to the short life of the electric heating wire, we can use the second part of the vehicle's human body infrared detection circuit to control its work. Therefore, the second part of the function is infrared detection of the human body inside the vehicle. When a human body is detected, the alcohol sensor is first passed through a large current of 0.5-2S to rapidly heat the sensor, thereby quickly entering a normal working state (for example, the normal heating sensor needs to be preheated 1 - 2 minutes to work properly), then start the corresponding circuit.
Central processing circuit: using single-chip microcomputer for intelligent processing, control voice reminder and protection.
Voice circuit: If the alcohol content is close to the traffic safety standard, you will be careful to drive carefully. If the safety standard is exceeded, the action circuit operates and warns the driver to drive.
Action circuit: The engine is directly cut off according to the processing result of the control circuit.
The car automatic driving protection system diagram is shown in the figure. With this car drunk driving automatic protection device, it effectively controls the traffic accident caused by drunk driving. This system can also be used in other situations where it is strictly prohibited to control the operation of the wine. Such as forklifts, cranes.

The system circuit diagram of the drunk driving automatic protection system map uses the alcohol sensor to detect the alcohol concentration in the vehicle. When the alcohol concentration exceeds the standard, the relay in the circuit acts to cut off the car engine and prevent the car from starting. As shown in the figure, this circuit is simple to control. As long as the alcohol concentration in the car exceeds the standard, it will act, so the application has limitations, such as taxis are not suitable.