Can a Arduino UNO have enough output voltage and amperes to trip a standard automotive 12v dc relay?
If not what do I need to trip the relay.
I am looking to control multiple relays (4) that would carry higher volts and amps to control a 12 v dc motor.
If the UNO does not have that capability, what would you suggest?
Thank You!
Hey @ProStreet,
Depending on a relay, you can calculate the current that it will be drawn from Arudino output. Arduino can handle up to 20mA, so if your calculated current is bigger than this, you shouldn’t connect it directly.
Safest and cheapest way to connect it is over transistor. Also, you can buy an optocoupler and connect it over it. Here is a great tutorial how to calculate this current and how to connect your relay to Arduino over transistor:
Usually, people buy already prepared relay boards that have all necessary components, like these ones:
https://www.robotshop.com/en/catalogsearch/result/?q=relay+board&order=relevance&dir=desc
No it doesn’t, about 20-25ma per output pin is all you can do. For a 12 volt mechanical relay, you’ll need a FET transistor, or any transistor that can be a switch. You’ll have to check the specs on the relay for the current required for the coil. Usually about 2 amps is standard. If your using a solid state relay, ck the data sheet to see how much current is required to turn the relay on. The Solid State relay will be a lot lower, from 5 - 200 ma.
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Appreciate the info
THANK YOU