I bought four 0.28$/pc electromagnet dual filter switchers, today they arrived:
From product description:
- When the red line is connected to the positive pole and the white line is connected to the negative pole, the lens switches to the white crystal glass;
- When the red wire is connected to the negative electrode and the white wire is connected to the positive electrode, the lens switches the coated crystal glass.
I just tested it with an Arduino Uno. According product description product heats up for 5V and electro magnet should be on for short time only. It stated also that electro magnet draws 0.24A for 5V, which I confirmed with my constant power supply.
I flashed bitlashdemo for interactively being able to modify digital lines:
I connected the switcher to Uno pins 8 and 9.
This bitlash command line flips polarity, powers electromagnet for 100ms, and then turns power off:
An Uno digital pin can deliver only 20mA, but all I can say is that it works, perhaps because current flows for only 100ms?
This is video where you can hear the switching. I did put a blue dot on one glass as well so that the switches can be seen as well: