Best way to power an arduino, servos, steppers, and LEDs on one power supply

[Raxius]

I am working on a project that requires multiple different types of servos, stepper motors, and several leds. (This is my first super complicated arduino project, so it's a massive learning experience)
I have all of the programming 99% finished and now I'm trying to power everything, but I think I'm running into problems supplying enough current.

The parts specifically;
An arduino mega
2 tower pro micro servos 5v
2 low profile servos (9.3 kg-cm @6V)
1 larger servo (13kg @ 7.2V)
1 Nema Stepper motor (12V .4A)
controlled by an a4988 stepper motor driver (5V)
a few other boards for audio(5V)
and 32 leds.

My current power setup has the arduino mega supplying power to all of the 5V components with an 18.5 V 3.33A laptop power supply supplying power to the larger components and ideally the arduino mega too.

Everything runs pretty well when I'm powering the arduino mega and from my computer via usb, the 5V components for the 5V pin, and everything from the power supply with voltage regulators that needs more than 5V. Occasionally it does lose power and restarts when I'm really making the servos work, but I assume that's from the usb port not being able to supply enough current.

When I try to power the arduino with 12V from the power supply as well, everything kind of pulses, like it's getting power and then immediately losing power. Same result when using a 12V 10A power supply.

So here's the question part! What would be the best way to wire several components with different voltage requirements from just one power supply?
Would the 12V/10A or the 18.5V/3.33A power supply be more appropriate?
Can anyone suggest specific voltage regulators? (I have regulators for 5V, 6V, 12V, and some lm317 variable regulators. All I think are rated at 1.5A)

If you need any more specific details don't be afraid to ask.

Thanks in advance!

[Southpark]

If you run from one power supply, you just got to make sure that this power supply has adequate power handling...... Then you can could use a combination of DC-to-DC converters.... eg. buck converter or boost converter generate other required regulated voltages.

If the 'parent' (main) supply has high enough voltage, then you could possibly use buck-converters (step-down) only (without needing boost-converters, step-up).

[terryking228]

Hi,

That's a lot of things to wire up, and servos and steppers produce quick changes in current draw,

What is the physical configuration of all this?

Where Is Ground??  

What is metal-case and what other physical configuration do you have??

I suggest you read over THESE PAGES about planning electrical systems.

[Raxius]

Hi,

That's a lot of things to wire up, and servos and steppers produce quick changes in current draw,

What is the physical configuration of all this?

Where Is Ground?? 

What is metal-case and what other physical configuration do you have??

I suggest you read over THESE PAGES about planning electrical systems.

Thanks for the quick response. That page on electrical planning definitely gave me some insights. I'll definitely be looking a few more pages on that site.

The physical configuration I currently have is all of the boards, regulators, and motor wires plugged into a large breadboard and all of the motors set up in a test fixture similar to how they will be in the final body. I plan on getting everything soldered onto proto-boards once everything is finalized.

The ground is currently set up similarly to my power; everything 5V grounded to the arduino, everything else to the power supply ground. Getting everything grounded to a common ground will be my next step.

What do you mean by "metal-case" and "other physical configuration"?

[terryking228]

Hi,

What do you mean by "metal-case" and "other physical configuration"?

Typical 'industrial' devices have a metal chassis, and most devices are attached to it. 

Wiring through a breadboard may also add resistance and also add coupling between closely-spaced connections.

Let us know how it goes...

[Raxius]

Just thought I'd give a quick update. I went ahead and ordered some buck converters and adjusted them for each of the voltage retirements and that seems to have solved my power problems. everything is working great. That may change when I get the motors hooked up properly with loads attached, but I doubt they'll need more then the 3 amps the buck converters can give.