Mini power supply – Upgraded !
The original USB powered mini power supply idea seems to have been quite popular, so i’ve upgraded it.
It’s simply a Voltage and Amperage display with a boost circuit.
Both items are very inexpensive and create a good reliable 4-30V adjustable power supply.
I don’t know what the current limits are in practice, but would expect that regular hobbyist loads up to 1A to be fine with voltages from 4 to 30V. The USB power input (or batteries etc) will dictate the available power throughput.
The boost modules state a max load current of between 2A and 3A.
Example modules, shipping to USA
Voltage & Amperage display:
https://www.ebay.com/itm/0-100V-10A-LED-DC-dual-display-digital-current-and-voltage-meter/352123821626
$2.84 free ship
Boost circuit:
https://www.ebay.com/itm/DC-DC-Boost-Buck-step-up-down-Converter-XL6009-Solar-Voltage-hot-ASS/263449146010
$1.41 free ship
Cost = $4.25