• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Get free circuit help 24/7

  • 1000+ Circuits
  • Privacy Policy
  • About Us
  • Contact
  • Disclaimer
  • Videos – Circuit Test Results
You are here: Home / 555 IC Circuits / Make this Simple Set Reset Circuit using IC 555

Make this Simple Set Reset Circuit using IC 555

Last Updated on February 15, 2021 by Swagatam 18 Comments

In this post we learn a simple IC 555 set/reset application circuit for activating or deactivating a relay alternately.

Circuit Operation

This electronic set reset circuit is very simple, easy to implement and very useful.

It can provide you many applications options in cases where it may be necessary to toggle (switch on and off) any electrical or electronic device

Understanding the ON-OFF or set/reset operation of the timer switch 555

To operate the timer 555. In this popular integrated circuit there a relay is connected via a BJT with the intention of connecting or disconnecting of the device to be controlled.

Manual activation may be performed via two momentary push ON switches. One serves to activate the device under control and the other for deactivating the same.

When the circuit is operating, activation of switch 1 (SW1) enables the pin2 of 555 linked to 12 volts normally, pulling it to 0 volts such that the timer output (pin3) is activated, allowing voltage 12 volts here. Thus, high output activates the relay 555 through the transistor Q1 (which saturates)

For disabling the relay, simply switch 2 (SW2) is pressed.

This puts pin 6 of timer 555, at a high voltage temporarily. The output of 555 that is pin3 now gets a low voltage level at its output, deactivating the transistor in the course, and clearing of the relay.

Circuit Diagram

Note: In the explanation of the circuit, it is proposed to be fed with 12 volts, however it may work well even with a voltage range from 5-15 volts. One can use a 9 volt battery PP3, and thus have a much portable circuit.

IC 555 pinout

IC 555 pinout specifications

List of circuit components for the above explained IC 555 set reset circuit

- Resistors: R1 = R2 = 3.3M, R3 = 10K, R4 = 1K
- Capacitors: C1 = 10nF
- Transistor: BC547
- Rectifier Diode: 1N4148 or equivalent
- Diode LED: 1 red
- Integrated circuit: NE555
- Relay: 1 with identical voltage to the supply voltage of the circuit
- Switches: 2 momentary or similar push ON contact. (SW1, SW2)
- Other: battery connectors (CN3), switches (CN1, CN2). View the latest chart.

By: Manisha Patel




Previous: Blinking 3 LEDs (R,G,B) Sequentially Using Arduino Circuit
Next: 4 LED Temperature Indicator Circuit

About Swagatam

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials.
If you have any circuit related query, you may interact through comments, I'll be most happy to help!

You'll also like:

  • 1.  How Electret Microphones Work – Full Tutorial and Diagram
  • 2.  5 Watt Stereo Amplifier Circuit with Bass Treble Controls
  • 3.  2 Simple Fastest Finger First Circuits Explained
  • 4.  How Mosquito Traps Work
  • 5.  Understanding SG3525 IC Pinouts
  • 6.  How to Control Servo Motor Using Joystick

Please Subscribe (Only if you are Genuinely Interested in our Newsletters)


 

Reader Interactions

Comments

    Your Comments are too Valuable! But please see that they are related to the above article, and are not off-topic! Cancel reply

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

  1. Search Related Posts for Commenting

  2. Seun says

    Please how can I use this circuit as astable mode with 1 cycle without resetting it

    Reply
    • Swagatam says

      Please read the following article, for all the details:

      IC 555 Pinouts, Astable, Monostable, Bistable Circuits with Formulas Explored

      Reply
  3. mal swift says

    Hi Swagatam,
    I am looking to build an oscillating circuit based on 555 timer/s.
    I wish for the circuit to drive a relay on for a time, then off for a different amount of time,
    I want to be able to vary the periods of on-time and off-time.
    Example On for 10 sec then Off for 2 sec. the change the timing altogether
    to say On for 5 seconds then Off for 20 seconds.
    Is it possible to have this performance from 555 circuit.
    Thanks for your thoughts,
    Mal

    Reply
    • Swagatam says

      Hi Mal, it may be possible to some extent. You can refer to the PWM based designs in the following article, and use one of them as per your suitability

      https://www.homemade-circuits.com/ic-555-oscillator-alarm-and-siren-circuits/

      Reply
  4. Adeyemi says

    Good day sir, please how can I make 555 timer for 5secs delay for power on and power off. Thanks

    Reply
    • Swagatam says

      Adeyemi, please search “555 timer” in the search box, you will find many options

      Reply
  5. James Skews says

    I’m looking for a simple on off timing relay, turn switch on powers relay 10s on then shuts down for 10s then repeats again and again 12v coil. Or a 14 pin DPDT combined timer relay repeat. Or do you think it’s just a easy to bye it on ebay?
    Jim

    Reply
    • Swagatam says

      you can try the following circuit

      10 second ON/OFF timer 555

      use 100uF for the C

      connect the relay directly across pin 3 and the ground line

      Reply
  6. German Cabrera says

    Si prolongo el sw1 y 2 con cable utp y utilizo 2 placas se genera un rebote y al apagarce una se enciende la otra porque puede ser??

    Reply
    • Swag says

      Intente conectar condensadores a través de los terminales del interruptor y verifique si eso ayuda. Puede usar 0.22uF o cualquier condensador hasta 1uF.

      Reply
  7. nitin chaudhari says

    Hello sir,
    Is there any cmos ic can be uset for set reset circuit with low power consumption than NE555 , so that can be used with battery with long life. Pls if possible publish a post with circuit.
    Thanks in advance

    Reply
    • Swag says

      Hello Nitin, You can find many CMOS based circuits if you search it online, I presently do not have it in this website…however if reducing current consumption is your main requirement in that case you can also try a transistor based design, as discussed in the following example post

      https://www.homemade-circuits.com/simple-gate-openclose-controller-circuit/

      Reply
  8. Geoff Nutley says

    Hi Swagatam, Thank you for the confirmation, yes I have a diode on the relay coil. You are right about the quality of the IC's they are the "dodgy 10 for a dollar ones", I shall invest is some decent ones.
    Thank you
    Regards
    Geoff

    Reply
    • Swagatam says

      you are welcome Geoff!!

      Reply
  9. Geoff Nutley says

    Thanks Swagatam,
    The basis of what I am trying to achieve is I need to hold a solenoid active for around 10 seconds,the trigger is a high. I tried a 555 monostable and got the time with capacitor and resistor values, but trigger for this is a low so I ran pin 2 through a BC547 to switch the signal to ground and send pin 3 high. This worked a few times and now pin 3 stays high all the time , I think it may be fried. The output of pin 3 goes through a BC547 a 12 volt relay to the solenoid. The solenoid is 12V 1A,the relay coil 50mA and I have 10K resistors on the BC547's. Do you think I am on the right track or is there a better way.
    The trigger voltage is 5 volts.
    Regards
    Geoff

    Reply
    • Swagatam says

      Hi Geoff, you have done everything correct in your design.

      Did you connect a diode across relay coil?

      I cannot see anything wrong in your design, may be the IC itself is not a good quality one, you can try replacing the IC…or the BC547 could also be examined for the same.

      Reply
  10. Geoff Nutley says

    Hi Swagatam, I was just wondering if I could ask you about a circuit that is based on the above circuit but has a different trigger requirement.
    Regards
    Geoff

    Reply
    • Swagatam says

      Hi Geoff, you can feel free to ask it.

      Reply


  11. COMMENT BOX IS MOVED AT THE TOP


Primary Sidebar

Electronic Projects Categories

  • 3-Phase Power (15)
  • 324 IC Circuits (19)
  • 4017 IC Circuits (51)
  • 4060 IC Circuits (25)
  • 555 IC Circuits (92)
  • 741 IC Circuits (18)
  • Amplifiers (49)
  • Arduino Engineering Projects (82)
  • Audio Projects (84)
  • Battery Chargers (75)
  • Car and Motorcycle (87)
  • Datasheets (45)
  • Decorative Lighting (Diwali, Christmas) (31)
  • DIY LED Projects (81)
  • Electronic Components (97)
  • Electronic Devices and Circuit Theory (35)
  • Electronics Tutorial (99)
  • Fish Aquarium (5)
  • Free Energy (34)
  • Games (2)
  • GSM Projects (9)
  • Health Related (17)
  • Heater Controllers (23)
  • Home Electrical Circuits (98)
  • Incubator Related (6)
  • Industrial Electronics (26)
  • Infrared (IR) (39)
  • Inverter Circuits (94)
  • Laser Projects (10)
  • LM317/LM338 (21)
  • LM3915 IC (24)
  • Meters and Testers (54)
  • Mini Projects (153)
  • Motor Controller (64)
  • MPPT (7)
  • Oscillator Circuits (12)
  • PIR (Passive Infrared) (8)
  • Power Electronics (33)
  • Power Supply Circuits (66)
  • Radio Circuits (9)
  • Remote Control (46)
  • Security and Alarm (56)
  • Sensors and Detectors (116)
  • SG3525 IC (5)
  • Simple Circuits (72)
  • SMPS (30)
  • Solar Controllers (60)
  • Timer and Delay Relay (51)
  • TL494 IC (5)
  • Transformerless Power Supply (8)
  • Transmitter Circuits (38)
  • Ultrasonic Projects (12)
  • Water Level Controller (45)

Follow Homemade Circuits

Facebook
Twitter
YouTube
Instagram
My Facebook-Page
Quora

Feeds

Post RSS
Comment RSS

Circuit Calculators

  • AWG to Millimeter Converter
  • Battery Back up Time Calculator
  • Capacitance Reactance Calculator
  • IC 555 Astable Calculator
  • IC 555 Monostable Calculator
  • Inductance Calculator
  • LC Resonance Calculator
  • LM317, LM338, LM396 Calculator
  • Ohm’s Law Calculator
  • Phase Angle Phase Shift Calculator
  • Power Factor (PF) Calculator
  • Reactance Calculator
  • Small Signal Transistor(BJT) and Diode Quick Datasheet
  • Transistor Astable Calculator
  • Transistor base Resistor Calculator
  • Voltage Divider Calculator
  • Wire Current Calculator
  • Zener Diode Calculator

© 2021 · Swagatam Innovations