Question (Can/how) do you wire multiple power supplies?

[Deadbolt Don]

Hello I could use some advice for using more than one power supply to power car amplifiers and Virtual pinball solenoids and knockers.
I have a few 300/350w ATX power supplies that I would like to use for this setup.
I have them all wired so I can turn them on with a switch. Obviously just one of the 4 pin plugs won't have the ability to carry the amperage the the Amplifiers will draw. So I have read that combining ALL the 4 pin plugs will help with available amps on that line.
SO 2 questions..
First is : Does a 300 watt power supply have 300w available to ALL voltages? 3.3v 5v. & 12v? So if all the 12v was combined there would be 300w @ 12vdc (roughly 25A)...
Second: Can I take 2 power supplies and combine ALL the 12v pos. & neg. together? Rather than having one "dedicated" power supply for amplifiers. then 2nd for other stuff, when there may be unused power still available from the first power supply.

 

[lvt]

I thought the solenoids are running on 24V?

 

[Ralston18]

What make and model PSUs? Quality and efficiency matter. A labeled 300 watt PSU will not deliver 300 watts.

And the connectivity used (series, parallel) could easily lead to dangerous conditions.

Start with the following link within this Forum:

https://forums.tomshardware.com/faq...-selecting-the-right-one-for-the-job.1608758/

Then sketch out ( a schematic) how you plan to make the actual connections.

Include the devices (you mentioned amplifiers and solenoids) in your schematic.

Are you using the PSUs in two projects: car speakers and some sort of pinball machine. Not sure about the requirement for physical devices in a virtual machine - more explanation needed.

Overall, what you have in mind is not likely to end well.

 

[Deadbolt Don]

In General what they are powering is kind of irrelevant.
The main thing is will 2 power supplies connected in parallel (wired in series the voltage will go up) across the 12v lines of each 4 pin plug Be okay? The end goal is to have a larger amount of amperage than if I used one power supply. After that the power will go through a fuse/distribution block and out to the individual devices, what ever they may be. Consider that they MAY be higher current circuits.
One PSU had a label with some info I will check tomorrow when back in shop.