Traditional Chinese Civil joint anti-theft alarm: Circuit Design, Parts List & Workshop Prototype Guide

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Civil joint anti-theft alarmIn order to cooperate with social security, various household anti-theft alarms have emerged. However, due to their single function and small insurance coefficient against theft, if there is no one at home during the day, the anti-theft alarm will have no protective effect. Therefore, people have lost interest in household anti-theft alarms. Some places implement joint defense devices for the whole hospital, that is, the door of the courtyard is locked at all times. If an outsider wants to enter the courtyard to visit relatives and friends in a certain building or floor, he must first contact the device on the door and talk to the household being visited. After the head of the household is approved, a signal is sent, and the door is opened. However, thieves rarely use the door and mostly pass through the wall. Moreover, the cost of this kind of communication device for joint defense facilities is relatively high, and the device also brings great inconvenience to the residents of the hospital. Nowadays, people have to develop anti-theft iron doors and balcony anti-theft nets. Anti-theft iron doors and anti-theft nets can only block the gentlemen, but not the "villains". Moreover, the waste of metal materials is large and should not be promoted.To this end, the author has designed a "civilian joint anti-theft alarm" and the trial installation has shown good results. It is now introduced as follows for manufacturers to follow and enthusiasts to install themselves.1. Functional featuresThis joint anti-theft alarm has the following functions:(1) No matter which household in the joint defense system the thief enters through the door or window, as long as the door or window is slightly opened (that is, not fully opened), the alarm will sound immediately;(2) Each household in the joint defense can not only hear the loud alarm sound, but also know which household the thief wants to enter and steal through the indoor display device;(3) A thief enters the house and finds an indoor alarm display device. Even if he cuts off the power of the device or even smashes it, it will not help; the alarm will still sound;(4) During the day or night, if there are only the elderly, children or women indoors, and criminals break into the house to rob or commit mischief, they can send a call for help to all households in the joint defense department;(5) When residents encounter an unexpected incident, they can send an alarm to each household in the joint defense department for help.Features of this joint anti-theft alarm:(1) Low cost. Calculated based on a unit with 12 households (6 floors, 2 households on each floor), the cost of each unit does not exceed 300 yuan, and the average price per household is 25 yuan;(2) Easy to install and does not affect the indoor appearance;(3) Using DC power supply, it is not affected by power outages and consumes almost no power when in the alarm state;(4) No switches are exposed, it is highly resistant to damage, easy to use and suitable for all ages;(5) It is suitable for both multi-household joint defense in the same unit and exclusive multi-room joint defense.2. Circuit working principleThe circuit principle of the civil joint anti-theft alarm is shown in Figure 24-1; it is composed of household alarm action, display and main alarm.Figure 24-1(a)Figure 24-1(b)One-way thyristors SCR1, SCR2, transistors BG1, BG2, relays J1, J2 and light-emitting diodes LED form a household alarm action and display circuit. Among them, the one-way thyristor SCR1 and the relay J1 are the password switch circuit; the transistors BG1, BG2, SCR2, relay J2 and the light-emitting diode LED are the alarm action and display circuit. The alarm action is a combination of closing and opening. As long as either one of the two switches K3 and K4 is open (K3) or closed (K4), the alarm actuator will act immediately, triggering the main alarm. …

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