Showing posts with label door. Show all posts
Showing posts with label door. Show all posts
Wednesday, September 4, 2013
Electronic Security Door Key Circuit
Circuit Diagram
Description
Source Sam Electronic Circuits
Description
A different circuit of electronic lock very simple, one and does not need a lot of materials in order to it is manufactured. The right keys of code should be stepped with the right line, so that is activated the optocupler IC2. If from error is stepped switch that does not belong in the combination, then the lock is trapped. In order to we restore the regular operation of lock, it should we press switches S1 or S12. Switch S1 makes Reset of lock externally and the S12 internally, the door. The Code the circuit as he is connected it is 147 and it can change, very easily, changing the connections in the switches of keyboard. The optocupler IC2, can drive any exterior circuit as Relay etc, ensuring simultaneously electric isolation the two circuits. The circuit can be also supplied from a battery 9V..
Part List
- R1-7-9=1Kohm
- R2-3-4-5=100Kohm
- R6 =10Kohm
- R9 =47Kohm
- IC1 = 4066
- IC2 =4N25
- Q1-2=BC550
- S1...11=Push button sw or keyboard
- S12=Push button normal closed
- All resistors is 1/4W 5%
Source Sam Electronic Circuits
Labels:
circuit,
door,
electronic,
key,
security
Saturday, August 3, 2013
Door Handle Alarm Circuit Using Transistor
The automatic door handle alarm circuit gives a audible alarm and glows a LED when somebody touches the handle of the door. The circuit is latching type and continues to produce sound until it is switched off.

The transistor Q1 is wired as an astable multi vibrator whose output is used to bias transistor Q2 to conduction. As a result the transistor q3 and LED are in OFF state. When someone touches the handle, the capacitance of the human body damps the oscillations of Q1.The cuts the biasing of Q2 and it goes OFF.As a result the current flows to the base of Q3 , it conducts and LED glows. If the switch S1 is ON the transistor pairs Q4&Q4 which is wired in the latching mode is triggered and the Buzzer Z1 is activated. When the person removes his hand from door handle the LED goes OFF but the buzzer continues to beep. The only way to mute the buzzer is to open the switch S2. All capacitors must be rated 15V.
A 9V battery or 9V DC power supply can be used to power the circuit. To make L1 wind 25 turns of 0.4 mm enameled copper wire on resistor R2 and solder the ends of the wire to the resistor leads. This unit will stand for the R2 as well as L1 because both are parallel in the circuit. A readily available 10mH inductor can be used for L2. Connect the point A in the circuit to the door handle using a long wire.

The transistor Q1 is wired as an astable multi vibrator whose output is used to bias transistor Q2 to conduction. As a result the transistor q3 and LED are in OFF state. When someone touches the handle, the capacitance of the human body damps the oscillations of Q1.The cuts the biasing of Q2 and it goes OFF.As a result the current flows to the base of Q3 , it conducts and LED glows. If the switch S1 is ON the transistor pairs Q4&Q4 which is wired in the latching mode is triggered and the Buzzer Z1 is activated. When the person removes his hand from door handle the LED goes OFF but the buzzer continues to beep. The only way to mute the buzzer is to open the switch S2. All capacitors must be rated 15V.
A 9V battery or 9V DC power supply can be used to power the circuit. To make L1 wind 25 turns of 0.4 mm enameled copper wire on resistor R2 and solder the ends of the wire to the resistor leads. This unit will stand for the R2 as well as L1 because both are parallel in the circuit. A readily available 10mH inductor can be used for L2. Connect the point A in the circuit to the door handle using a long wire.
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