Can I use an external DC power supply instead of USB-C?
Yes. There are two ways to use an external DC power supply with the MagWLED-1, depending on your setup.
Option 1 — Power both the board and the LEDs from DC
Connect the external power supply’s positive and negative outputs to the + and − connectors on the MagWLED-1 terminal block. The voltage must match the LED strip’s target voltage. MagWLED-1 will automatically step that voltage down to power the microcontroller.
If your LED strip has convenient power injection wires at the input, you can keep the included pigtail connector inserted and inject power as per this photo:
If not, you will likely want to remove the included pigtail connector. Split the power supply’s input and outputs with a “Y split” and then replace the pigtail’s red wire (see photo below) with one of the positive outputs from the power supply and the pigtail’s black wire with the power supply ground cable.
Important:
- Do not power the board by DC and USB-C at the same time. This can cause current to flow between the two power sources.
- Voltage above 12 V will likely destroy the MagWLED controller. If you need to drive higher voltages, use Option 2 below.
Option 2 — Power the LEDs externally, keep USB-C for the board
The MagWLED-1’s USB-C input supports up to 3 A of LED current via USB PD. For larger installations (350+ LEDs, high-density strips), you’ll need an external DC power supply to handle the LED current while the MagWLED-1 provides only the data signal.
In this configuration the USB-C adapter does not need to supply power to the LEDs — it only powers the microcontroller, WiFi, and WLED firmware.
Critical: you must connect a common ground. Connect the GND of the MagWLED-1 (available on the terminal block or solder pads) to the GND of your external power supply and LED strip. Without a shared ground the data signal has no reference and the LEDs will not respond correctly or will behave erratically.
Leave MagWLED-1’s positive output disconnected — only GND and the data line connect to the strip.
Inline fuse
Always protect high-current wiring with an inline fuse between the power supply and the LED strip. MagWLED-1 has a built-in fuse, but this fuse is circumvented when powering externally.
Sizing rule of thumb: fuse at roughly 125 % of your expected maximum current draw, but never higher than the current rating of your wire.
| Strip size | Estimated max draw | Suggested fuse |
|---|---|---|
| ~100 LEDs at 5 V | ~6 A | 8 A |
| ~300 LEDs at 5 V | ~18 A | 20–25 A |
| ~100 LEDs at 12 V | ~3 A | 5 A |
| ~300 LEDs at 12 V | ~8 A | 10 A |
These are estimates — actual draw depends on LED type and brightness settings. When in doubt, size conservatively (smaller fuse) and increase if it trips unexpectedly under normal use.