My Light Diagram

A different Electronic Security Door Key Circuit Diagram 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.  Read : Heat Detector Alarm using UM3561   Electronic Security Door Key Circuit Diagram 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. Read : Radio Wave Alarm Part List   ...

If some intruder tries to open the door of your house, this circuit sounds an alarm to alert you against the attempted intrusion. The circuit (Fig. 1) uses readily available, low-cost components. For compactness, an alkaline 12V battery is used for powering the unit. Input DC supply is further regulated to a steady DC voltage of 5V by 3-pin regulator IC 7805 (IC2). Fig. 1: Circuit of the door guard Assemble the unit on a general-purpose PCB as shown in Fig. 4 and mount the same on the door as shown in Fig. 3. Now mount a piece of mirror on the door frame such that it is exactly aligned with the unit. Pin configurations of IC UM3561 and transistors 2N5777 and BC547 are shown in Fig. 2.  Fig. 2: Pin configurations of UM3561 and transistors 2N5777 and BC547 Initially, when the door is closed, the infrared (IR) beam transmitted by IR LED1 is reflected (by the mirror) back to phototransistor 2N5777 (T1). The IR beam falling on phototransistor T1 reverse biases npn transistor T2 and IC...

Do your kids leave the door to the refrigerator open? Or does your celery reach out to keep the door from closing properly when you turn your back? Here's a simple circuit that beeps whenever the door is open for an extended period of time (which will also put a little pressure on the fridge loiterers in the house). Simple Refrigerator Door Alarm Circuit Diagram  The photocell has a very high resistance in the dark which drops very low when the door opens and the light turns on. The 22 uF capacitor begins to charge and when the voltage reaches the zener voltage, the beeper sounds. Closing the door allows the capacitor to discharge through the 10 meg.  resistor, resetting the beeper. The circuit draws very little power when the door is shut and only draws significant current when the beeper is sounding. The transistor may be a single NPN darlington such as the MPS-A14 or two 2N4401's connected as shown. Other types will also work. The delay may be changed by changing the value ...

Circuit Diagram Description The door latch alarm circuits are simple and effective and easy to construct. Normally the alarm is in de-activated mode by keeping the switch s1 in off state which can be done with a lock and key kind of switch. Number of doors can be guarded against the intrusion by keeping or connecting the reed switch in series fitted with the help of a magnet. The reed switch can be fitted in such an way that the magnet is fixed on the door, in normal conditions when the door is closed reed switch will be held close to the magnet and hence the reed switch is kept closed , when the door is opened the reed switch contact is opened , this triggers an SCR, the gate of an SCR is connected to its cathode through the reed switch as long as the switch is closed the SCR dose not fire but when the door is opened the SCR is fired supplying an voltage to the alarm circuit. Source -http://www.electronguide.com/circuits_pages/DoorLatchAlertSystem.html

Circuit Schematic Diagram Description This circuit can be used in front doors for visitors to communicate or it can be wired up in the front gate for conversation, this circuit is fairly simple but its worth, it dose not use any sought of condenser mic for voice transmission if uses the speaker for both the transmission purpose and for the reception purpose, the heart of the circuit is the operational amplifier LM386 which is used to amplify the voice signal gain adjust is provided by the 5k preset and the pot resistor 10k is used as the volume control. Source - http://www.electronguide.com/circuits_pages/Doorphonecircuit.html

Do your kids leave the door to the refrigerator open? Or does your celery reach out to keep the door from closing properly when you turn your back? Here's a simple circuit that beeps whenever the door is open for an extended period of time (which will also put a little pressure on the fridge loiterers in the house).  Simple Refrigerator Door Alarm Circuit Diagram  The photocell has a very high resistance in the dark which drops very low when the door opens and the light turns on. The 22 uF capacitor begins to charge and when the voltage reaches the zener voltage, the beeper sounds. Closing the door allows the capacitor to discharge through the 10 meg.  resistor, resetting the beeper. The circuit draws very little power when the door is shut and only draws significant current when the beeper is sounding. The transistor may be a single NPN darlington such as the MPS-A14 or two 2N4401's connected as shown. Other types will also work. The delay may be changed by changing the ...

This simple Door Chime protects the door and gives a loud Alarm tone when there is an attempt of theft. The circuit is too simple and battery operated. A Normally Closed (NC) reed switch and magnet is used to trigger the circuit. Alarm generator is the popular ROM IC UM 3561. This 8 pin IC has an inbuilt oscillator to generate 4 siren tones like, Ambulance siren, Police siren, Fire brigade siren and Gun sound. The different tones can be selected using its pin 6 connected to VCC, Ground or not connected. Frequency of oscillation is determined by the 220K resistor connected to the pins 7 and 8 of the IC.UM 3561 is the low power IC and its maximum voltage rating is 3 volts. So Zener diode ZD is used to give 3 volts supply to IC. Medium power NPN transistor T1 amplifies the output pulses from IC1 to a loud siren. Tiny Door Guard Circuit diagram: Magnet can be a small sized one that is to be fixed in the door using double sided adhesive tape. Fix the circuit board in the door frame. Fix Ree...

This is the simple Simple Refrigerator Door Alarm Circuit Diagram. Does your celery reach out to keep the door from closing properly when you turn your back? Here's a simple circuit that beeps whenever the door is open for an extended period of time (which will also put a little pressure on the fridge loiterers in the house). Simple Refrigerator Door Alarm Circuit Diagram The photocell has a very high resistance in the dark which drops very low when the door opens and the light turns on. The 22 uF capacitor begins to charge and when the voltage reaches the zener voltage, the beeper sounds. Closing the door allows the capacitor to discharge through the 10 meg.  resistor, resetting the beeper. The circuit draws very little power when the door is shut and only draws significant current when the beeper is sounding. The transistor may be a single NPN darlington such as the MPS-A14 or two 2N4401's connected as shown. Other types will also work. The delay may be changed by changing th...

The main part of this doorbell circuit are two NE555 timer ICs.When some one presses switch S1 momentarily, the loud speaker sounds a bell tone as long as the time period of the monostable multivibrator built around IC1. When the switch S1 pressed, IC1 is triggered at its pin 2 and output pin 3 goes high for a time period previously set by the values of POT R4 and POT R5.When the output ofIC1 goes high it resets IC2 and it starts to oscillate to make a bell sound through the speaker.The IC2 is configured as an a stable multi vibrator whose oscillation frequency can be varied with the help of POT R5.By adjusting the values of R4 & R5, modifications on the tone are possible.