If you would like to run an RC4 device on a much lower voltage, like a small 3.6V LiIon battery, we have a simple modification you can install to shift the standard operating voltage range from 6V – 35VDC down to 3.6V to 6VDC.
IMPORTANT: IF YOU INSTALL THIS MODIFICATION AND THEN APPLY MORE THAN 6VDC TO THE POWER INPUT, YOU WILL DAMAGE THE DEVICE. THIS DAMAGE IS NOT COVERED UNDER WARRANTY.
The basic power supply circuit is the same in all RC4 Series 3 devices, so this mod can be applied to any devices, including micros and larger devices in cases.
The modification bypasses the on-board 5V regulator, routing the input voltage directly to the input of the on-board 3.3V regulator. Some circuitry on the 5V power bus will not withstand voltages above 6V, so you must NOT apply more than 6V when this modification is installed.
Cleanly and precisely installing this modification does not void your warranty — we understand that sometimes you need to do this kind of thing to use our products most effectively.
BUT doing the mod poorly, or subsequently applying more than 6V, may result in damage that is NOT covered under warranty. Proceed at your own risk.
Here is a schematic :
As well as a photo of an M4micro with the mod installed :
In the photo above, the yellow wire jumper on the device on the right is the modification. That’s all it is — it’s very simple and easy to add or remove. The device on the left does not have the mod installed, shown for reference.
WHEN DOING THIS FOR THE FIRST TIME, MODIFY ONLY ONE DEVICE TO CONFIRM YOU GET THE RESULTS YOU NEED.
Do not modify many devices until after you have done the job and tested it successfully on one device.