close a circuit


i want to use my arduino as an SPST-Switch for a device i build.

i have two cables with low voltage that come out of my device. when i hold them together the device gets activated.

so i only need contact/no contact

i want this to get done by my arduino. since i dont have a relay lying around and the voltage is very low, is it possible to just plug it to the arduino?


How low is low voltage? Are they sharing common ground potential?

Cheers, Kari

There is not enough information to answer that question.

You would need to know if it was voltage activation (voltage on one side is applied to the other) or current activation (it depends on current/energy flowing through the link). The first is easy. Having looked at the Arduino circuits I don't think the second is possible except for current in the ma/ua range -- which can be supplied by the pullup/pulldown resistors).

And that is assuming that the connection does not transfer information... but the answer would be much the same anyway.

When you publish the schematics then the question can be answered.

No circuit, no answer.

hi if you only need put or join the two cables terminal use one relay ,it serve also for insulate your arduino for protection

use one relay

since i dont have a relay lying around