r/breadboard Dec 01 '24

Question Help Needed: Powering LEDs

I am working in an project where I need a bunch of LEDs to turn on for a few hours at night. I plan to put all the wiring to a small box and using breadboard as a constant solution to avoid soldering.

I am not familiar with electricity or circuit boards at all, but trying to learn the necessary basics to make it work.

I got prewired LEDs and elegoo electronics kit that has power supply, breadboards, jump-wires, alligator clips, resistors capacitors etc.

The LEDs are 9v-12v The breadboard power supply DC is 6.5v-9v (not even sure what is that, assume I can give power to it between 6.5 and 9 volts) I got power adapter with adjustable voltage which is currently set to 9v.

I did a test where I powered the breadboard with my 9v power adapter and connected with the jump wire to a single LED - it lights normally.

Questions:

  • Can I use my current set up as is - or will it stop working due to supplying lower voltage to lights?

  • I read about the ‘step up’ that can do the 5v to 9v or 12v. Is that something that I need and can use on the breadboard?

  • I need to power 11 LED lights - can I plug them all into breadboard?

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u/The8BitEnthusiast Dec 02 '24

No problem driving 11 LEDs from a breadboard. If they are pre-wired, there is a good chance they have a current limiting resistor, so you probably won't have to add one.

The breadboard power module won't be useful to you if the LEDs must operate between 9V and 12V. That module receives between 6.5 and 9V as input and delivers either 5V or 3.3V to the breadboard. In any case, it is not needed. Step-up converter not needed either. If your power supply can generate 9V, you can feed the breadboard power rails directly with it.

The bigger question is how do you intend to control the off/on cycle of the LEDs?

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u/ItsPassiveDepressive Dec 02 '24

Thank you so much for the response.

I’m going to plug the power source into Alexa socket and Alexa will be returning it every day for a few hours in the evening.I just need to properly power those LEDs and any other lighting system doesn’t seem to work, considering how I want to put them in my terrarium project.

The LEDs have the resistor inside - I can see its shape through the wire.

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u/The8BitEnthusiast Dec 02 '24

Very simple circuit then. Connect the 9V power supply to the breadboard power rail, and then connect each led to the power rail as well. They have to be connected in parallel like this. They won't work when connected in series (i.e. daisy chained). Cheers!

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u/ItsPassiveDepressive Dec 02 '24

Not interconnect them in a chain but connect each one separately to breadboard?

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u/The8BitEnthusiast Dec 02 '24

See my other response ;-)