Please help with PSU question

Question

Hope someone can help me, I am really getting confused.

So I am just getting into electronics, and a project i would like to do is to make my own LED strip lighting for a workbench.

I understand that a 12V strip needs a constant 12V supply, and if the usage is 0.900A per strip / meter and I want 2 strips, I will need a minimum of 12V 1.8A supply. I also understand that I should increase the supply by 20% so as to not over tax the unit. So a good supply would be 12V 2.25A.

If I have a PSU that provides 12V 5A is this too much or is it safe as the LEDS will only draw what they need?

Thanks in advance

Be careful when writing units. 'M' for mega (1,000,000). 'm' for milli (0.001). 'A' for ampere and 'V' for volt. So it's 0.9 mA and 12 V. Capitals matter! — Transistor, Aug 15 '20 at 02:18
@Transistor: I think the current is 0.9 Amp/meter, or 900 mA/meter. — Peter Bennett, Aug 15 '20 at 02:21
LEDs need current limiting for safety. If you don't have such a circuit, make sure the voltage never goes above 12V. — Indraneel, Aug 15 '20 at 04:18

score 1 · Answer 1 · answered Aug 15 '20 at 03:39

So long as the rated current of the power supply is higher than the current needed by the LED strips (or any device) you will be fine.

Devices only take as much current as they need. A good analogy for it is to think of current as a rope. You can't push it, just pull it. So devices will only pull what they need. The power supply won't push it into the devices.

Please help with PSU question

1 Answers1