I have a very simple circuit which consists of a battery, a load (lamp), and a button (on-off).

I want to a very simple and cheap (without Arduino or microcontroller) way to open and close the circuit automatically when the button is on and stop when button is off.

Press (ON), the lamp lights up (close) then after 2 s the lamp goes off (open) automatically. Repeat this process continuously untill I press off so the circuit is open and the light off.

Battery voltage: 7.4 V @ 1 A
Lamp power: 3 W

enter image description here

I want it to be like this:


  • \$\begingroup\$ We need many more details. What is the battery voltage? What is the lamp current or wattage? \$\endgroup\$
    – AnalogKid
    Jun 27, 2022 at 21:23
  • 2
    \$\begingroup\$ The text of your question is confusing at best. Please edit so it makes more sense. You talk about a "button" but show a "switch" in the schematic. You also talk about pressing on the "lamp" which does not make much sense. Also need to clarify if the "'switch" is a momentary or alternate action device. \$\endgroup\$ Jun 27, 2022 at 21:25
  • \$\begingroup\$ So - you want a Flasher Relay? \$\endgroup\$
    – brhans
    Jun 27, 2022 at 21:33
  • 4
    \$\begingroup\$ that is a long way to say that you want the lamp to flash when the switch is closed \$\endgroup\$
    – jsotola
    Jun 27, 2022 at 22:16

1 Answer 1


I don't fully understand the "after 2 seconds" portion, but essentially I think you're asking for a latching relay?


This essentially toggles the output when the input is activated. This means; when the input (button) is activated, the output switches to the opposite state, of what it currently is.

If you are looking for a timer function, a latching relay can be combined with (or replaced by) a timed relay (for example "off delay").


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.