Using 2 Power Supplies with Ramps 1.4

ok this should be an easy one for veterand however I am not a veteran of any form of electronics.

My situation....

I have 2 PSU's

The typical you would purchase off of ebay for powering ramps

1 - 12v 20a 240watt

2- 12v 30a 360watt

Ok my question.

I would like to use both to power my ramps so that one powers components that use the least power and use the other to power
the hot bed,

Can I connect the psu's like i have illustrated in the photo attached.



Thanks for any advice you may have...

I would not do it that way. I read something along time ago about the ground and it causing problems. What you could do is use a relay for the ps1 run off D8 (or is it 10) as it only runs the heatbed.

Dual power supplies can be used in some cases, but they are not like a battery, you can't just stick switch mode supplies in parallel unless they are designed for it.

If you join the +ve lines together and - ve lines together any voltage imbalance between the supplies can cause a massive current and then fire as both supplies try to balance the voltages to slightly different values.

What you can do is join just the grounds together and run separate loads off the +ve lines. These separate loads can communicate between each other providing the signalling voltage is less than the supply voltage and there is a common ground. So you could de-solder the heated bed transistor and run it off the secondary power supply with the gate signal coming from the ramps providing you join ground wires. I would not recommend this however!

the real question is why?

you already have a 12v 30amp power supply, that should be well and truly enough to power the entire printer on it's own unless you are running 4 heated beds and even then

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Ok thanks for the input, Ill just use the 30a 360watt power supply and omit the thought of using them both. Thanks again.