• Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Need circuit help? Post them in the comments! I've answered over 50,000!

Blog | Categories | About | Contact | Calculators-online
You are here: Home / Security and Alarm / Security Alarm Circuit using RCWL-0516 Microwave Radar Sensor




Security Alarm Circuit using RCWL-0516 Microwave Radar Sensor

Last Updated on August 22, 2024 by Swagatam 6 Comments

This security alarm circuit using RCWL-0516 microwave radar motion sensor will detect any moving thing in the restricted area and turn ON an alarm sound.

Table of Contents
  • Circuit Description
  • Parts List

The RCWL-0516 is basically an advanced motion sensor using microwave radar signals.

I have already discussed the working of RCWL-0516 elaborately, which you can read for more details.

Circuit Description

The following figure shows the full circuit diagram of the proposed security alarm circuit using RCWL-0516 microwave radar motion sensor.

warning message: electricity is dangerous, proceed with caution
RCWL 0516 alarm circuit

Referring to the above figure, the working of the circuit can be learned from the following points:

The circuit operation is actually very straightforward, thanks to the outstanding RCWL-0516 motion sensor module.

As we know that the RCWL-0516 module will detect anything that moves within its detection range and in response produce a positive voltage at its OUT pin.

Therefore as soon as a potential intruder or burglar tries to trespass the restricted zone, it is quickly detected by the RCWL-0516 module.

This causes the RCWL-0516 "OUT" pin to generate a positive voltage which is sent to the base of the TIP122 transistor via the 4.7k resistor and the LED.

The LED lights up, and the TIP122 switches ON turning ON the alarm device.

The alarm starts sounding indicating a possible intrusion in the protected zone.

If you want the circuit to be functional only during nighttime or in darkness, you can add an LDR on the back side of the RCWL-0516 module.

Whenever an intruder is detected, the RCWL-0516 module keeps the siren activated as long as the intruder movement is detectable in the area. It shuts down the siren after a delay of 2 seconds once the moving object is terminated from the detection zone.

Parts List

  • Resistors are 1/4 watt 5% CFR
  • 4.7k = 1
  • 10 ohm = 1
  • Semiconductors
  • Transistor TIP122 = 1
  • RED LED 3.3 V, 5mm, 20mA = 1
  • Diode 1N4007 = 1
  • 12V Siren Module = 1
  • RCWL-0516 module = 1
  • 12V 1 amp Power supply SMPS = 1

You'll also like:

  • 1.  Make this SleepWalk Alert Circuit – Protect yourself from Sleepwalking Dangers
  • 2.  PIR Burglar Alarm Circuit
  • 3.  SMS Based Laser Security Circuit
  • 4.  RFID Security Lock Circuit – Full Program Code and Testing Details
  • 5.  GSM Fire SMS Alert Project
  • 6.  AC 220V Over Current Monitor and Cut OFF Circuit

Filed Under: Security and Alarm Tagged With: 0516, Alarm, Microwave, Radar, RCWL, Security

About Swagatam

I am an electronics engineer and doing practical hands-on work from more than 15 years now. Building real circuits, testing them and also making PCB layouts by myself. I really love doing all these things like inventing something new, designing electronics and also helping other people like hobby guys who want to make their own cool circuits at home.

And that is the main reason why I started this website homemade-circuits.com, to share different types of circuit ideas..

If you are having any kind of doubt or question related to circuits then just write down your question in the comment box below, I am like always checking, so I guarantee I will reply you for sure!

Previous Post: « Insect Light Trap Circuit for Protecting Crops
Next Post: Flashlight Activated Burglar Alarm Circuit »

Reader Interactions

Comments

  1. Udit says

    August 21, 2024 at 4:25 pm

    Please give the calculations of 4.7 k and 10k resistances. What is the use of 10 k resistor in the circuit.

    Reply
    • Swagatam says

      August 21, 2024 at 4:50 pm

      Both the resistor values are not critical, the 4.7k value must be such which allows minimum glow on the LED. It can be calculated using the formula:
      R = (5 – 3.3) / 0.02
      The 10k pull-down resistor is also not critical, its value must be such that it allows at least 1.5 volts at the base of the TIP122

      Reply
      • Udit says

        August 21, 2024 at 8:01 pm

        The output of rcwl 0516 is 3.3 volt and not 5volt so R will be 3.3 -1.8,because forward voltage of red led is 1.8 volt not as mentioned you. Please clarify. Also tell us the base current and collector current of tip 122.

        Reply
        • Swagatam says

          August 22, 2024 at 8:56 am

          Thanks for the correction, I mistakenly assumed the output to be 5V.
          I have corrected the diagram according to 3.3V output.
          The LED must be 3.3V 20mA type.
          No resistor is required for the LED, although you can use a 10 ohm series resistor for better safety.
          For calculating base resistor for TIP122 you can use the following formula:
          R = (3.3 – 1.2) * hFE / Siren current

          Reply
          • Udit says

            March 17, 2025 at 9:23 pm

            if 10 ohms is used, base current will increase. for proper base current 1k resistor should be used with 5 volt output from rcwl 0516.

            Reply
            • Swagatam says

              March 18, 2025 at 7:57 am

              The logic high from the OUT pin is 3.3V, so 10 ohms is fine for the LED, considering the LED fwd V is also rated at 3.3V.
              You can use the formula for calculating the resistor value.
              1k can be also used if the LED is high bright type.

              Reply

Need Help? Please Leave a Comment! We value your input—Kindly keep it relevant to the above topic! Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

circuit simulator image

Subscribe to New Posts




Categories

  • Arduino Projects (89)
  • Audio and Amplifier Projects (132)
  • Automation Projects (17)
  • Automobile Electronics (101)
  • Battery Charger Circuits (83)
  • Datasheets and Components (104)
  • Electronics Theory (143)
  • Free Energy (37)
  • Games and Sports Projects (11)
  • Grid and 3-Phase (19)
  • Health related Projects (25)
  • Home Electrical Circuits (12)
  • Indicator Circuits (14)
  • Inverter Circuits (88)
  • Lamps and Lights (142)
  • Meters and Testers (69)
  • Mini Projects (46)
  • Motor Controller (64)
  • Oscillator Circuits (27)
  • Pets and Pests (15)
  • Power Supply Circuits (108)
  • Remote Control Circuits (50)
  • Security and Alarm (64)
  • Sensors and Detectors (101)
  • Solar Controller Circuits (59)
  • Temperature Controllers (42)
  • Timer and Delay Relay (49)
  • Transmitter Circuits (29)
  • Voltage Control and Protection (39)
  • Water Controller (36)




Other Links

  • Privacy Policy
  • Cookie Policy
  • Disclaimer
  • Copyright
  • Videos
  • Sitemap




People also Search

555 Circuits | 741 Circuits | LM324 Circuits | LM338 Circuits | 4017 Circuits | Ultrasonic Projects | SMPS Projects | Christmas Projects | MOSFETs | Radio Circuits | Laser Circuits | PIR Projects |

Social Profiles

  • Twitter
  • YouTube
  • Instagram
  • Pinterest
  • My Facebook-Page
  • Quora
  • Stack Exchange
  • Linkedin



  • Recent Comments

    • Swagatam on LM35 IC Temperature Controller Circuit with Push Button
    • Neeraj on LM35 IC Temperature Controller Circuit with Push Button
    • Swagatam on LM35 IC Temperature Controller Circuit with Push Button
    • Swagatam on Wideband Amplifier Circuits
    • Neeraj on LM35 IC Temperature Controller Circuit with Push Button

    © 2025 · Swagatam Innovations