I have 4.8V 0.5A Light Bulb and want to use RPI's GPIO pins to power it. How can I do that?

  • 2
    You will need a relay or MOSFET as io pins only provide 40 ma Commented Jan 23, 2017 at 18:17
  • can I use transistors? Commented Jan 23, 2017 at 18:24
  • Given its properly suited for your needs that's what I should have said instead of a MOSFET . Also depending on your power source you may need an external power source for the light. I'm not sure how much amperage is available through the 5v io pin Commented Jan 23, 2017 at 18:25
  • You can use a transistor (BJT or MOSFET) to control the ground connection (there are some constraints with regard to the relationship between the gate and output voltages, but not so much the input). You should be able to draw 1/2 amp from the 5V rail (USB devices may do so), although with regard to this and the quality of your power supply see the discussion here: raspberrypi.stackexchange.com/a/59878/5538
    – goldilocks
    Commented Jan 23, 2017 at 19:20
  • @giorgishengelaia Do you mean " I have 4.8V 0.5A Light Bulb and want to switch it using RPI's GPIO pins. How can I do so?" Commented Jan 24, 2017 at 3:45

1 Answer 1


This is an excellent question as a lot of people want to drive loads using their Raspberry Pi. I'm not sure why you received a -1 your question may have need rephrasing.

Yes, You can drive a load using a Bipolar transistor or a MOSFET. A MOSFET will be more efficient.

Driver Circuit

The MOSFET in the schematic above is a general purpose one. You will have to choose a Logic Level MOSFET that will work with 3.3V on the gate.

You can add isolation using an optocoupler as well if you want higher isolation between the power rails.


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.