Cirquit to control 5v 3A using Arduino

Projects General Guidance
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Hello, i'm new on this forums and need help of you guys,

I don't know if this is the correct section or even if this is the apropriate place to put my question

I have a project of a simplistic ACPI controller using a Arduino board, the arduino will switch on/off a 5v/3A power supply.

I have a basic knowloge of electronics and i prefer to use my own solutions instead a pre-built module because of the price. (Since the hole project is aimed at low price).

But, if possible, i like to use something that waste less power as possible at the output (i like to get as close as possible to 5v/3A at the output).

I readed about PNP/NPN transistors but i dont know if exists transistor for this kind of power, i've only found schematics for 1A at top.

I've also readed about using relays but it's need a secodary transistor to drive it and make noise when switch on/off, so, i prefer to not use them.

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There are cheap 10A 240VAC (60V DC) relays that take no more power to switch than a led.
Some, a bit less cheap, have opto-isolated inputs.

For 3A 5V you should look into FET's, Field Effect Transistors, in the General Electronics section here.

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5V RELAYS

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Thanks for the fast replies, it really helped

I cannot import those products because the highly taxes from my country are really expensive, for instant, this $4 relay can easly became $15 for me because of the taxes.

For some reason, the components here arent so expensive, cost really less to build my own.

I will look for the FET's, thank you :smiley:

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Sometimes we get members from Israel who have the same problem. It's kind of sad when a country taxes away innovation by it's own citizens but then they might compete with corporations that you can bet get big breaks.