Using an Arduino Mega2560 R3 to control multiple Neon tubes with 8channel Relay

I am trying to see if it is possible to power multiple neon transformers using a 12vdc 1.5A power supply via an Arduino/relay setup.

I wish to connect multiple element spectral tubes for my element display. I wanted to try using a single wall wart and an Arduino/relay to cycle power to each transformer as I have no need to power each spectral tube at the same time. I have both the Arduino Uno R3 and the Mega 2560 R3, an 8 channel relay, and a bunch of other spare parts (jumper wires, breadboards. etc.).

I have attached pictures of the Neon transformer and Wall wart powers supply.

Please let me know if this is feasible, and if so what other parts I may need to obtain.

If there are any videos/forums discussing this topic that I missed feel free to point me in that direction.

An Arduino has no issues controlling relays - provided they have the appropriate driver hardware (most relay modules have that built in).

Relays are a good way of switching AC loads, make sure the relay is rated to way more than the current that transformer takes.

I just can't see the purpose is of that 12V DC supply. Now if you had thrown a 5V DC supply in the mix, that'd make a lot more sense.

So the transformers for the neon tubes need 12V input, and that is why you want to use a 12V wall-wart?

Yes, this should work. It would be best if the relays are 12V also. If the relays are 5V, you will have to power them from the Arduino's regulator. Even with only one relay active, this might cause the regulator to overheat.

PaulRB:
So the transformers for the neon tubes need 12V input, and that is why you want to use a 12V wall-wart?

Yes, this should work.

I'm afraid you missed the DC part in the 12V... Transformers don't tend to do much with DC.

PaulRB:
So the transformers for the neon tubes need 12V input, and that is why you want to use a 12V wall-wart?

Yes, this should work. It would be best if the relays are 12V also. If the relays are 5V, you will have to power them from the Arduino's regulator. Even with only one relay active, this might cause the regulator to overheat.

PaulRB,

Correct each neon transformer needs a 12vdc input. The 8 channel relays say they are rated for 28vdc 10A. The goal is to avoid using 8 separate wall warts by using the relay. Since I would be using a voltage that is significantly lower than that would it be acceptable?

I'm new to using Arduino/relays so excuse any dumb questions.

Any resources on how to assemble such a set up would be greatly appreciated. I've seen several videos using 120vac to control lights and other appliances, but none on how to use the 12vdc through the relay to power several dc devices.

A relay is just a switch. Connect wires, done. Just make sure it's within the specifications - 12VDC and 1.5A is no problem.

wvmarle:
I'm afraid you missed the DC part in the 12V... Transformers don't tend to do much with DC.

wvmarle,

The neon transformers have a 12vdc 1A input and output 2000vac 1mA hence the need for a 12vdc power supply.

Again very new to this so forgive any stupid questions/answers, or if I'm missing something fundamental.

wvmarle:
I'm afraid you missed the DC part in the 12V... Transformers don't tend to do much with DC.

I didn't miss that, just assumed the "transformers" also have an oscillator built-in.

uminum23:
The 8 channel relays say they are rated for 28vdc 10A.

That's the contact ratings, and yes they are OK. But I was asking about the coil ratings. Sorry I did not make that clear. If the coils require 12V, you can power them directly from the wall-wart and avoid the danger of overheating the Arduino's regulator.

uminum23:
I have attached pictures of the Neon transformer and Wall wart powers supply.

It would have been helpful if you had done that. If you could not figure it out, read the forum guide in the sticky post. Even better would be links to web pages with the specs or data sheets of those components.

If, once you have the circuit working, you find that the click sounds made my the relay are annoying, it would also be possible to use MOSFETs instead of the relays. Ask for advice about MOSFETs here before buying any.

PaulRB:
It would have been helpful if you had done that. If you could not figure it out, read the forum guide in the sticky post. Even better would be links to web pages with the specs or data sheets of those components.

Sorry I didn't realize the pictures were not uploaded I have included links to the components below.

Any direction to a relevant thread/ video of how such a system can be assembled would be greatly appreciated.

I am a complete amateur and really appreciate your time in assisting me.

Neon transformer:
Page: Transformer 3000V 15mA - Information Unlimited

Specs:

Wall Power supply:
Page: 12VDC 1.5A Wall Adapter (Stripped Leads) - Information Unlimited

Let me know if I can supply any additional information, and thanks again for your time.

If it is 12vdc from the wall wart powering the neon device, then you switch the 12v using a relay or possibly a logic level MOSFET. My cat broke my "Live Nudes" neon sign years ago, so I can't experiment with that now.

This is how you should post links, so they can be clicked. Just hit the "insert link" icon and paste the address.

The link I most wanted to see was for the relays.

PaulRB,

Here's the link to the relay. Sorry for the incorrect style posting.

Thanks again for the help. Any links to more info on how to set up the system would be greatly appreciated.

https://www.elegoo.com/product/elegoo-8-channel-dc-5v-relay-module-with-optocoupler/

That should all work together - the main problem is the 12V power supply for the Arduino. For an experimental setup it's fine, for anything more permanent I'd prefer to add a buck converter to supply 5V to the Arduino (and move to a Nano for easier soldering).

The Uno will do fine; you need only 8 outputs, you didn't mention anything about inputs but you have lots of those available.

I prefer to use MOSFETs for switching DC loads. It's just that much more efficient.

When experimenting don't lead the 1.5A through a solderless breadboard, use wires. Those breadboards can't handle 1.5A well, it's just too much.

I think it's fine to power the Uno with 12V so long as the Uno does not have to power anything else significant at 5V. One relay might be ok. A fault in your code (during development, for example) could cause more than one relay to be active at once, and this would cause the Uno's 5V regulator to overheat and fail.

Unfortunately your relays have 5V coils, so will have to be powered by 5V such as the Uno's regulator. When switching 12V power, using 12V relays is better because the relays can be powered directly from the PSU.

I think this circuit will work so long as you don't accidentally activate more than one relay at once, but keep monitoring the Uno's regulator during testing to make sure it does not get too hot to touch.

I don't have any links about how to wire the circuit, but it will be straight forward. Power the Uno from 12V through the Vin or barrel socket. Power the relay board from the 5V pin it the Uno. Connect 12V to the COM connection of each relay and the transformers from the NO relay connections. Connect any 8 Uno digital pins (except 0, 1) to the relay inputs and of course common ground to all components.