The following diagram is a very easy and simple electronic combination lock based on IC LS7220. Component Part List: C1 = 1uF 25V C2 = 220uF 25V R1 = 2.2K Ohm Q1 = 2N3904 / 2N2222 […]
Category: Security
Car Alarm Simulator
This is a car alarm simulator which using the LED as a simulation output. This simple circuit can tell you whether your car is running or not by detecting the voltage difference when the car is […]
Safer Security System Alarm
Here the circuit diagram of safer security system alarm. There are many security systems use a closed loop of wires and switches arranged so that whenever a door or window is opened, the loop will be […]
DIY Simple Multitone Alarm
Here is the circuit diagram of simple multitone alarm. This is a low cost circuit which is simple and easy to build. The main components of this circuit is based on dual op-amp MC1458 and LM […]
DIY Electronic Cardlock Security System
Here is the DIY electronic cardlock security system that can be used as a lock to turn on dan turn off important electronic/electrical appliances. When card is inserted, depending upon the position of punched hole on […]
Car Audio System Anti Theft Security
This is the circuit diagram of car audio system anti theft security which can be effectively used to protect and secure your expensive car audio system from stealing. This simple circuit designed based on popular CMOS […]
Door Knob Touch Alarm
This is door knob touch alarm for your home security purpose. The alarm will be activated when someone touch the metal door knob. This circuit won’t work on full metal door.
Laptop / Notebook Protector
This is laptop / notebook protector circuit to protect your laptop or notebook or netbook from being stolen. Fixed in-side the laptop case, it will sound a loud alarm when someone tries to take the laptop. […]
Car Anti-Theft Protection with Buzzer
This is the circuit diagram of car anti-theft to protect and increase the security of your car, prevent your from stealing. This circuit is very simple, low cost and easy to built. When key-operated switch S2 […]
Electronic Door Lock Security Key
This is the circuit diagram electronic door lock security key system. It means that this security system circuit is the combination of pressed key itself (not the mechanical). The output can be connected to drive the […]