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This intelligent electronic lock circuit is built using transistors only. To open this electronic lock, one has to press tactile switches S1 through S4 sequentially. For deception you may annotate these switches with different numbers on the control panel/keypad. For example, if you want to use ten switches on the keypad marked ‘0’ through ‘9’, use any four arbitrary numbers out of these for switches S1 through S4, and the remaining six numbers may be annotated on the leftover six switches, which may be wired in parallel to disable switch S6 (shown in the figure). When four password digits in ‘0’ through ‘9’ are mixed with the remaining six digits connected across disable switch terminals, energisation of relay RL1 by unauthorized person is prevented.For authorized persons, a 4-digit password number is easy to remember. To energies relay RL1, one has to press switches S1 through S4 sequentially within six seconds, making sure that each of the switch is kept depressed for a duration of ...

Ever been looking for your keys, and wanted to call them, before you realize that they are hideously analog pieces of metal? Or wanted to let someone into your house when you’re not at home, without having to lend them your keys? Lockitron was the solution that descended from hardware heaven – a device that fits over the lock on your door and that is controlled via an app. It raised $2.2M on Kickstarter but missed its original shipping deadline by 1.5 years, leaving its backers in a deadlock (pun!). Are you one of them? Stop glaring at your empty mailbox and channel all your frustration into making your own awesome smartphone connected lock – The Bean Lock. [ ]

This electronic combination lock can be use with an outdoor gate. The functionality is implemented in software. It turns on a relay (usually to open a door) for a few seconds if someone enters the valid code. The relay can operate a power to open type electric strike with a shorting contact or a power-to-hold type electromagnetic lock with a breaking contact (we need the relay because these locks usually work with AC, not DC). The code can be changed any time after entering the current code. Current consumption of the circuit is low, because the PIC sleeps most of the time, and wakes up only for processing key presses. The 16F628A already contains an internal RC oscillator, so no crystal is needed. Type in the correct code and use # as 'enter'. The initial code is 623342. You can change the length of code as well. * is used to change the code. Type in the actual code then press *. If you didn't miss the actual code, the code change indicator LED will light up. Then type in ...

This Digital Electronic Lock Circuit Diagram shown below uses 4 common logic ICs to allow controlling a relay by entering a 4 digit number on a keypad. The first 4 outputs from the CD4017 decade counter (pins 3,2,4,7) are gated together with 4 digits from a keypad so that as the keys are depressed in the correct order, the counter will advance. As each correct key is pressed, a low level appears at the output of the dual NAND gate producing a high level at the output of the 8 input NAND at pin 13. Digital Electronic Lock Circuit Diagram The momentary high level from pin 13 activates a one shot circuit which applies an approximate 80 millisecond positive going pulse to the clock line (pin 14) of the decade counter which advances it one count on the rising edge. A second monostable, one shot circuit is used to generate an approximate 40 millisecond positive going pulse which is applied to the common point of the keypad so that the appropriate NAND gate will see two logic high levels whe...

Now here’s a digital lock unlike any other, as  it has only two buttons instead of the usual  numeric keypad. The way it works is as simple  as its keypad. Button S1 is used to enter the  digits of the secret code in a pulsed fashion-i.e. the number of times you press the but-ton is determined by the digit to be entered.  A dial telephone uses the same type of coding (now maybe there’s an idea?). Press four  times for a 4, nine times for a 9, etc. Pressing button S2 indicates the end of a digit.    Project Image :    Two-button Digital Lock Project Image   For example, to enter the code 4105, press  S1 four times, then press S2, then S1 once, S2  once, then without pressing S1 at all, press S2  again, then finally S1 five times and S2 once  to finish. If the code is correct, the green LED D1 lights for 2 seconds and the relay is energised for 2 seconds. If the code is wrong, the  red LED D2 lights for 2 seconds, and the relay  is not energised. To change the code, fit a jumper to...

This Digital Electronic Lock Circuit Diagram shown below uses 4 common logic ICs to allow controlling a relay by entering a 4 digit number on a keypad. The first 4 outputs from the CD4017 decade counter (pins 3,2,4,7) are gated together with 4 digits from a keypad so that as the keys are depressed in the correct order, the counter will advance. As each correct key is pressed, a low level appears at the output of the dual NAND gate producing a high level at the output of the 8 input NAND at pin 13. Read : Cheap Bicycle Alarm Schematics Circuit Digital Electronic Lock Circuit Diagram The momentary high level from pin 13 activates a one shot circuit which applies an approximate 80 millisecond positive going pulse to the clock line (pin 14) of the decade counter which advances it one count on the rising edge. Read : Emergency Light and Alarm Circuit Diagram A second monostable, one shot circuit is used to generate an approximate 40 millisecond positive going pulse which is applied to the ...