Digital Ber-password circuit

Posted on Feb 6, 2014

Circuit Kunci Digital Ber-password is the circuit diagram of a simple electronic combination lock usingLS 7220. Circuit Kunci Digital Ber-password Password Digital can be used to activate a relay for controlling (on & off) any device when a preset combination of 4 digits are pressed. The circuit can be operated from 5V to 12V. To set the combinatio

Digital Ber-password circuit
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n connect the appropriate switches to pin 3, 4, 5 and 6 of the IC through the header. As an example if S1 is connected to pin 3, S2 to pin 4, S3 to pin 5, S4 to pin 6 of the IC, the combination will be 1234. This way we can create any 4 digit combinations. Then connect the rest of the switches to pin 2 of IC. This will cause the IC to reset if any invalid key is pressed, and entire key code has to be re entered. When the correct key combination is pressed the out put ( relay) will be activated for a preset time determined by the capacitor C1. Here it is set to be 6S. Increase C1 to increase on time. For the key pad, arrange switches in a 3X4 matrix on a PCB. Write the digits on the keys using a marker. Instead of using numbers I wrote some symbols!. The bad guys will be more confused by this.

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