Battery powered Mantis microscope

[nickii]

Hello,

I thought I would share my latest project here. I wanted to get myself a Mantis microscope for a few years now. This time I finally gave in and bought one.
As you probably all know, these microscopes can get very expensive very quickly. My solution was to only buy only the head and two lenses (4x and 8x). Everything else I can make on my own.
I spent around 1100€ for the head and 600€ for the lenses with caps (always get the caps!). The arm would cost me another 800€ and what hurts the most - the power supply is 100€!!! For a 9V adapter!
Naturally, I bought a computer monitor arm. It is way more configurable and only costs 100€ on Amazon. The only thing you have to do is make your own mount for the Mantis head instead of the monitor.
But that can be done in 1 hour from some aluminum U profile. I really recommend this solution for microscope mounts to everyone.



Regarding the power supply, I carefully disassembled the head and looked at the circuit. It is much simpler than I imagined. There is only a DC power plug, 20 LEDs and 20 current limiting resistors. Their value is surprisingly low. Only 68 ohms. At 9V the current is around 40mA per LED. This did not sit right with me. There is absolutely no need for the current to be so high. The LEDs reach full brightness at 10mA. I am very glad I did not buy their 100€ power supply. I recommend anyone with a Mantis microscope to use a 5V power supply.

Another thing I found interesting is that the manual says not to connect the power supply directly to the head. I have no idea why.

In the end, I decided to make a battery pack. 4V from Li-ion batteries is just too perfect and clean to pass up. The current trough each LED is around 15mA. And I avoid the cable running down the arm and into the wall. I am using 2 18650 Li-ion batteries, a simple Chinese TP4056 charging module and a switch.

Everything is packed inside a small 3D printed enclosure. I had difficulties making it fit nicely around the body but I am pretty happy with the end result. Stl files are attached in a zip archive.

It is difficult to capture everything on only a couple images but here it is.

















Best regards,
Nik