Hi,
I was wondering if there was some kind of way to turn on/off a high voltage circuit with an Arduino. More specifically, is there a way using a use a signal from an Arduino pin to switch on/off a higher voltage circuit? What would be necessary to do so?
Edit: I was inquiring in regard to 120V circuits which as explained below is not high voltage
How high is this voltage?
Is it an AC or DC voltage?
What sort of current does this device draw?
When we know this then we can give you an answer.
Do you have the appropriate training to work with high voltage?
It would be AC, 120V, 0.3-0.6A. I did not take certifications into consideration. What would that entail?
What is the device you are powering with 120VAC?
You could use a relay module like this
Which Arduino? 3.3 volt or 5 volt?
is it a resistive or inductive load? see utilization-categories-ac-1-and-ac-3
typically a contactor rated at 10amps for a restive load would be 2 to 3 amps for a Squirrel cage induction motor
Thank you for all the responses. Prefferably a 3.3V Arduino. It would be a non-ohmic resistive load.
there are plenty of 3.3V relays on sites such as EBAY
you can do initial testing of code logic etc by using a low voltage LED as load
be careful when testing with 120volt AC mains
in particular if there are exposed soldered pads on the bottom of the relay PCB
I tend to mount high voltage relays/contactors/transformers/etc on a plastic base?
e.g. this relay block is operating two pumps, a motor and a solenoid all 250-Volt AC
OK so you want to switch 120 VAC with current less than an amp. Yes, you can use a mechanical relay or you can use a SSR (Solid State Relay). Your current demand is low so just about anything will work. Relays are available in nice modular form making for ease in setup and use.
Just as a footnote:
What is defined as high voltage?
The International Electrotechnical Commission and its national counterparts (IET, IEEE, VDE, etc.) define high voltage as above 1000 V for alternating current, and at least 1500 V for direct current.
What is the NEC definition of high voltage?
It cites the following NEC voltage standards: High Distribution - 1000 to 4160 volts. Medium Distribution - 50 to 1000 volts. Low Distribution - 0 to 49 volts.
Ron
entail
cites
I fixed it and that was actually a copy and paste from here. 
Ron
Thank you for all the responses and information. Apologies for the typo. I thought of 120V as high voltage; thank you for the clarification.
Safest way for beginners to do this: IoT Power Relay - COM-14236 - SparkFun Electronics
Can you explain that term please, I have not come across that before, and to me is seems to be a contradiction in terms? I have come across non inductive load, and a none capacitive load, or simply a resistive load.
It would help if you actually said what sort of devices you want to switch.
I would vote for an SSR like Ron_Blain. You can run it off a 3V3 signal. I would make sure it has a zero point crossing detector built in for proper switching on, and is not the type designed for dimming lights and the like.
No such a mother.......
Hi,
I came across that term searching whether LED lightbulbs are conductive or resistive. Here is more information:
See post #12
