New anti-theft alarm based on TWH9250 radar detection module

Burglar alarm of TWH9250 radar detection module with the substance constantly enrich and rapid improvement of people's living standards, people's safety awareness are constantly strengthen, many families and units installed security doors and windows, security doors and windows to ensure the personal and property safety. play a positive role. Important places like the vault, warehouse, Key Laboratory of like, however, rely on a simple anti-theft doors and windows is not enough, you must also install a burglar alarm device. Common burglar alarm infrared burglar alarm, touch burglar alarm, induction burglar alarm and magnetron burglar alarm; common drawback of these anti-theft alarm monitoring range memory in dead ends, and committing the crime for the criminal elements to provide the opportunity. In order to solve the problem of dead space monitoring not to adopt TWH9250 radar detection module [1], the design of a new type of all-round the dead ends microwave burglar alarm. the burglar alarm the an alarm detection should consider the anti-theft alarm with sound and light alarm function is also required on-site camera control, so, in the circuit structure In addition to the loop antenna for emitting microwaves on the design should also include the radar detection module, alarm integrated circuits, integrated audio power amplifier circuit infrared camera control circuit and the DC power supply circuit 5 parts. the burglar alarm circuit design

probing the Introduction module TWH9250

TWH9250 is a novel of the radar detection module, the module has the following characteristics:
< br> (1) microwave tube scanning emission detection distance;

(2) all-round no dead angle detection;

(3) low power consumption, can be battery-powered;

(4) internal circuit open collector output terminal is connected with a flexible, can directly drive a small relay action;

(5) end of light control and sensitivity adjustment end, to meet the kinds of occasions to use requirements;

(6) simple external circuit connected to the ring antenna and terminal implementing agencies, power can work. the module shape

TWH9250 pinout and internal circuit functional block diagram is shown in Figure

2. arises out with the loop antenna transmitted microwave signal to form a three-dimensional microwave alert network, when someone moving around in the net, it will produce human movement reflected back the microwave signal, microwave generation circuit weak low-frequency signals of moving objects. The signal is amplified by the two to about 70dB, and then turn into a double to identify the window voltage comparator circuit and the pulse width of the comparator circuit. When recognized that the amplitude and width of the signal voltage reaches the set requirements, the latch circuit is triggered, the trigger signal via the optical control door is supplied to the counter control circuit to perform the output delay processing, the delay time is set to 10s, and finally by the end-stage power tube collector output. To improve the stability of the performance of the microwave circuit, the accuracy of the comparison circuit, the various parts of the circuit by 4V and 7V regulators system separate power supply. The circuit when the initial power, subject to the 40s pre-stable time to enter the probe alert after as long as it does not power down, the circuit at any time in the detection state. TWH9250 module normal operating voltage of 12 V.

2, the alarm IC burglar alarm issued a similar fire engines sound, A2 uses LC246 alarm integrated circuits [1], and his first election the sound end that 8 pin power supply (3V), readers If you change the level of the selected sound end, the alarm sound can be obtained.

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