Wireless Switch Circuit Using CD4027

In our home devices are controlled with help of switches,sensor .Sometimes it dangerous if it physical contact with home appliances.To overcome these drawback the Light Dependent Resistor is replaced here so just pass the hand near to the LDR then the device is ON and to turn OFF again pass the hand above LDR is placed.

Read more..

The circuit has two 2 ICs namely LM714 and CD4027.The LM714 is an operational amplifier is used to compares the voltage while the hand is pass above LDR .The CD4027 is JK Flip-Flop work on master and slave concept,to give the state when the signal is given to any one of the input terminal and output is more than one.it consist four input pins JK flip flop as J and K along with set and reset pin and Qand Q¯ minus for output.

LM741 which is like a comparator for voltage ,LDR.There will be a reference voltage which is applied to non-inverting terminal as well as to LDR.The inverting terminal is connected with capacitors ,with a few additional components.

The whole circuit consists two mains parts ,few additional components for the voltage maintenance so it is easily to understand the operation of the circuit.The circuit is OFF until the hand is passed over the LDR.So the inverting terminal is in high state and the output side the pin is in low state.

The hand is pass near the LDR moves to high state compares with reference voltage ,in output terminal goes now high which supply a clock pulse to JK flip flop.With the positive going cycle so the clock changes occur. Set and Reset pin are not dependant on the clock and it started when high signal is provided to any one of the input pins.A diode is provided for the forward conduction to avoid the reverse voltage to the circuit .

In addition to the BC547 is connected to the JK flip flop terminal output is in high state means the transistor is connected to the relay the appliances can be connected via relay its get turned ON and OFF.

How to build Electronics projects Did you know

Skyfi Labs helps students learn practical skills by building real-world projects.

You can enrol with friends and receive kits at your doorstep

You can learn from experts, build working projects, showcase skills to the world and grab the best jobs.
Get started today!


The LM741 series are general-purpose operational amplifiers which feature improved performance over industry standards .The amplifiers offer many features which make their application nearly foolproof: overload protection on the input and output, no latch-up when the common-mode range is exceeded, as well as freedom from oscillations. The LM741C is identical to the LM741 and LM741A except that the LM741C has their performance ensured over a 0°C to +70°C temperature range, instead of ?55°C to +125°C. It has the overload protection on the input and output.No Latch-Up When the common-Mode Range is Exceeded.


The CD4027 dual J-K flip-flops are monolithic complementary MOS (CMOS) integrated circuits constructed with N- and P-channel enhancement mode transistors. Each flip-flop has independent J, K, set, reset, and clock inputs and buffered Q and Q¯ outputs. These flip-flops are edge sensitive to the clock input and change state on the positive-going transition of the clock pulses. Set or reset is independent of the clock and is accomplished by a high level on the respective input. All inputs are protected against damage due to static discharge by diode clamps to VDD and VSS.

Latest projects on Electronics

Want to develop practical skills on Electronics? Checkout our latest projects and start learning for free

Kit required to develop Wireless Switch Circuit Using CD4027:
Technologies you will learn by working on Wireless Switch Circuit Using CD4027:
Wireless Switch Circuit Using CD4027
Skyfi Labs Last Updated: 2021-07-05

Join 250,000+ students from 36+ countries & develop practical skills by building projects

Get kits shipped in 24 hours. Build using online tutorials.

More Project Ideas on Electronics

LED VU Meter Circuit
Internet of Things Based Intelligent Transportation System
Wireless Switch Circuit Using CD4027
IoT Based Biometrics Implementation on ECG
Biometric Attendance System with IoT
Wireless Electronic Notice Board using GSM
Three Axis Modern Trailer
Interfacing GPS with 8051 Microcontroller
GPS Ambulance Tracker
GPS and GSM based School bus tracking system
Accident detection system with GPS and GSM
Voice Controlled Wheel Chair
Finger Controlled Wheel chair
GSM Based Door locking and Unlocking system
Automatic Windshield Wiper
Ultrasonic Distance Finder Using 8051
Generating Electricity From Sound Waves
Turning Gravity into Light
Under Ground parking System using RFID
RFID Based Smart Ticketing Card for Local Trains
Sign Language Translator
PIC Controller Based Electronic Lock
Vehicle Tracker
Seven Segment Display Interfacing With PIC16F877A
Hover Board
Smart Wallet
Air Pollution Detector
Remote Control Home Automation Using PIC Controller
Foam Cutting Machine
Smart Headlamp
How to Design a Water Cleaning Boat?
Shower Temperature Sensor
Electromagnetic Shock Absorber
Pneumatic Vulcanizing Machine
Double Hacksaw Cutting Machine
GSM Based Weather Report
Rain Sensing Automatic Car Wiper
Night Vision security patroling-robot
Portable variable voltage supply
Pneumatic Wall Climbing Machine
Development of LabVIEW based Distribution Control System
GSM based Energy Meter and Load Control
Blood Oxygen Level Monitoring System
Height Measuring Cap
Collision Detector
Power Generation by Piezo-Electric effect
Magnesium doped cobalt ferrite nanoparticles
Attendance system
Wireless Power Transmission via Solar Power Satellite
Smart Horticulture
Cell phone operated Land Rover
PC based wireless appliance control
Anti-collision system for trains
Electronic notepad
Alarm clock radio
Cell phone jammer
Electronic Candle
Mesh enabled iot smart device for athletes with Bluetooth and wifi
Smart wearable Bluetooth fitness tracker
RFID - Classroom identification for blind people
Low cost fire alarm system
RFID based PC locking system
Basic Powerbank for smartphones
Intelligent Vehicle Control (RFID)

Subscribe to receive more project ideas

Stay up-to-date and build projects on latest technologies