When looking at power supplies, is it watts or amperage that matters?

When looking at power supplies, is it watts or amperage that matters?

I have a MKS Gen L V1.0 and it supports up to 24 VDC. I have a number of 19 VDC laptop power supplies here.

The recommended power supply for use with a mega+RAMPS 1.4 is 12 VDC at 6 amp = 72 watt.

Can I use a 19.5 VDC at 4.62 amp = 90 watt power supply with the MKS Gen L V1.0?

Or does my power supply need to be >= 6 amps?

I’m pretty sure the volts need to match exactly. Then, your power supply should at least match the amps required. More amps is okay.

1 Like

The board can do whatever, but the things you plug into it are going to want either 12V or 24V, using 19V will probably cause you a lot of issues.

Jason has it right match the volts you need, more amps is okay (nothing gained) less will not work.

The only things that I’m plugging into the board are stepper motors, and the LCD display, so 19.5 VDC should not hurt anything. The MKS Gen L V1.0 board supports the range 12 VDC to 24 VDC.

(Unlike the mega+ramps combination, which supports at most 12 VDC unless you remove a diode on the RAMPs board. I found this out the hard way. Anyone want a mega that needs a new voltage regulator?)

So you’re saying for our purposes (MPCNC, moving steppers) that I need the 6 amps, that 4.62 amps @ 19.5 VDC won’t be enough. What are the symptoms when you don’t have enough amps?

I have no idea if the LCD will be okay, I would assume the 5V reg will be good enough. I have no experience with voltages over 12V into any boards.


No. 12V x 5A=60W is what I recommend for everything including a hot end. 12W would probably be more than enough for a system without a 40W hot end heater. 19.5V x 4.62A = 90W…more than enough.