Retro Game Power Supply

[Bmoney]

I need help designing a buck converter. I want to make a one size fits all power supply with for my retro consoles. Relieving me of wall warts.

Problems I have:

1) Zero testing equipment 

2) Minimal electronics expertise 

3) No idea what mosfet to use

 

Goals of the project

1) 120v in to 5V. 9V, 10V, 12V, -12V, 18V

2) Simple barrel dc connectors on both ends

3) current protection on outputs and amp shutdown.  

4) about 12-16 outputs

5) Very Very low output ripple

6) Low Q range. (But I am really curious if the would affect older consoles with noise 2600's master systems, odessy etc. 

 

I see this being a great open source project and even a profit project. 

Any electronics people please help!

[Windows7ge]

You could modify a ATX PSU to output most of those voltages. Defaults voltages are 3.3V, 5V, 12V, -12V, and older PSU's support -5V. You could use small gadgets from other retailers to get 9V + 10V out of a 12V supply similarly with 18V at the cost of reduced current. This is all DC but the output should be smooth as electronics are sensitive to dirty power. If you need these voltages AC I can only think to use an auto transformer but that'd be big, heavy, and a tad bit dangerous, not to mention I don't think you can produce negative rails with one.

 

Just shooting ideas your way I'm not this type of tech savvy I've only tinkered in the field like building flashlights, high capacity power banks using off the shelf trinkets, voltage controlled Peltier plates for experiments, other basic stuff.

[Bmoney]

It be only DC

 

[Windows7ge]

11 minutes ago, Bmoney said:

It be only DC

 

All I can tell you is a computer ATX PSU would provide half your needs. They only output what the equipment draws they don't force feed current so your electronics should be safe. If there's a short anywhere they have short circuit protection and over current protection but no defined current limiting. Though I don't think you'll need current limiting with this type of power supply unless something goes wrong with the console you plug in and it doesn't immediately go over current or short circuit.

[straight_stewie]

52 minutes ago, Bmoney said:

I need help designing a buck converter. I want to make a one size fits all power supply with for my retro consoles. Relieving me of wall warts.

Problems I have:

1) Zero testing equipment 

2) Minimal electronics expertise 

3) No idea what mosfet to use

Sounds like you're in a pickle then!

I think the best way to approach this problem would be to, instead of defining some generic "one size fits all" solution (which will invariably end up being a "one size fits none" solution), you identify the outputs that you currently need, and then design the thing in such a way that it's modular and easily expandable.

One such solution that comes to mind is to build a box that pipes your local AC whatever onto a bus that different power supplies can connect to: Essentially this is just many power supplies in one box.

[Unimportant]

6 hours ago, Bmoney said:

I need help designing a buck converter.

 

6 hours ago, Bmoney said:

120v in

The term "buck converter" tends to stand for a non-isolating switching step-down converter, if you want 120V in (presumably mains) you're going to need a fully isolated switchmode power supply, otherwise it's going to be a death trap.

 

Besides such a project obviously being extremely dangerous for someone with "Minimal electronics expertise", it's also impossible without decent lab equipment. You'd at the very least need a oscilloscope (a real one, not one of those toy ebay kits) to view the device in operation, determine errors and determine performance (how are you going to even check your low ripple requirement without sensitive equipment that can determine the ripple?).

 

Parasitic elements also play a very important role in switching power supply design, it takes a lot of skill and experience simply to design a good PCB, even if someone gave you a schematic. Certain parasitic elements are determined in the lab because they're near impossible to model/calculate, snubber design comes to mind, which again requires proper equipment.

 

Heck, even designing the required magnetics (transformer) is a project in and off itself.

 

If you want to go trough with this I'd suggest you try walking first in stead of running. Try designing a linear power supply first, with a normal transformer, that does what you want. Perhaps with adjustable voltage and adjustable current limit. Don't use IC's but make it out of discrete components so you actually understand what is going on, if you can't do that you should not even be dreaming about designing a SMPS.