control a circuit

i have ready circuit which is controlled by press button. The circuit have inbuilt power supply and gnd. I want to switch on button using arduino. how could i ?

I don't understand. If you have a press button and a circuit you want to power, why not just use it directly?

regards allan

allanhurst: I don't understand. If you have a press button and a circuit you want to power, why not just use it directly?

regards allan

i want to arduino pin as switch to that button, instead of press.

What voltage and current does your circuit use?

Just use a servo, attach a hammer to it and control the servo to hit the button when you want to press it.

Or in other works, tell us everything about that magic circuit ;)

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Yeah, a (reed)relay will always work but there probably is a possibility that is not that extremely bulky...

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septillion: Yeah, a (reed)relay will always work but there probably is a possibility that is not that extremely bulky...

we do not have enough information to make any determinations. if the signal is to an opto and passing 5mA, how much more do you need ?

if the switch is for a 50hp motor at 208 volts... say about 150 amps.... what could we offer that was a bit more bulky ?

In all situations you can replace a switch with a relay, even for the 50hp motor. Granted, you need a proper relay.

spycatcher2k: You could use a MOSFET or a transistor instead.

Or even plain nothing if it's just CMOS ;)

So indeed, we need more info :)