Resistor Chip Arrays
Product name: two-way anti-theft alarm welding diy kit
Product model: TJ-56-52
Working voltage: DC5V
PCB size: 40 * 51mm
Description:
The dual-channel anti-theft alarm is composed of the dual-time-base integrated circuit NE556, the four-two-input NAND gate CD4011 and the surrounding components. There are two NE555 time-base circuits inside the NE556. Because they are encapsulated in a chip, they can achieve good consistency, and their driving capacity is large, and the working frequency range is wide. The circuit alternately outputs two signals of different frequencies, drives the speaker to achieve two different sound effects, and the red and green indicator lights also flash alternately. The two-way alarm function can be realized by setting K1 and K2 on or off.
Circuit principle
1. Connect the power supply (close S1), connect K1, and disconnect K2. The 4th pin of IC1 (4011) outputs high level, the 3rd pin outputs low level, the 4th and 10th pins of IC2 (NE556) do not work without voltage, and the alarm indicators LED1 and LED2 do not light.
2. Disconnect K1 and K2, and charge the capacitor C4 with the power supply. When the voltage on C4 increases to the threshold voltage of the NAND gate, the 4th pin of IC1 outputs low level, the 3rd pin outputs high level, the 4th and 10th pins of IC2 get reset level and work normally, the 5th pin outputs high and low change level, and the indicator lights of IC1C and IC1D drive alternately, and the 9th pin outputs two pulses of different frequencies, Two different sounds are emitted through the V1 drive speaker. K1 is open, K2 is closed or both K1 and K2 are closed. The working process is consistent.
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Condition : New
Type : Voltage Regulator
Origin : Mainland China