I've got a nice programmable power supply for my projects, however I wanted to be able to easily use it as a power source for working with my light boxes and other things. Since some of my projects are simply dimmable LEDs or fans or other constant-current PWM-controlled devices - but others are little SoC controllers (like ESP32/D1 Mini) - I wanted to also be able to send non-PWM power.

My requirements:

• Able to isolate from the power supply with an indicator light to it's status.
• Works with a wide range of voltages (namely 5-12v).
• Select from straight or PWM power with a switch.
• Would have a USB-A and 5.5x2.1 DC jack on the front.
• Would have two fixed cables out the back with USB-C and a 5.5x2.1 male jack.
• Wouldn't be a nightmare to work in.
• Would print strong with minimal use of supports.

This is what I came up with.

When the unit has power and is off, the power switch glows red indicating it is receiving power.

Flip it on and it glows green.

If the DPDT switch is pointing to the master switch it is straight voltage, if it's pointing to the PWM dial it is providing PWM power. This is across all outputs and there are no voltage regulators so you can put any voltage to any output. Be careful not to send the wrong voltage out! You could easily sent 12V to a 5V device if you do not double-check your power supply!

The master RGB Switch is wired up to have the red LED connected to NC and the green LED to NO. Ground is connected to common, and LED+ back to input V+. In fact, all positive wires are simply tied together. When the switch is “off,” the red LED is the only thing receiving power. When it is “on” the green LED and all other components receive power. The blue LED lead is not used.

The DPDT switch was tricky. On rail 1 common is Supply ground, with side A supplying to “DC IN-” on the PWM controller and side B shorting to rail 2's side B. Rail 2's side A is the returned “Motor V-” from the PWM controller and the rail 2's common is output V- to all jacks/cables. PWM V+ out is not used, only V+/- In and V- out.

The side panels just snap in place with a little effort. A 3x6mm oval accepts the input line and two 3mm holes provide an exit for 22AWG two-conductor cables (I put a 5.5x2.1 jack on one, the other was a USB-C pigtail). The side panels have retention notches that might need to be trimmed down depending on how cleanly your filament prints (this prusament required a little effort).

The vent holes are unnecessary, but were fun to draw 😁