I have a Futaba radio with switch that can send 3 different PWM signals (1000, 1500, 200 multi state selection). I have been trying to use these signal for an on/off Video transmitter power source and gripper relay in the following manner:
- ->1000, state 0, both parts are off
- ->1500, state 1, Video transmitter power activate, gripper relay off
->2000, state 2, Video transmitter power activate, gripper relay on
I used an Arduino RC filter (4.7K, 100nf) to make different level of voltage (.2,2.5,5), also used a pair of IRF540 N-Mosfet. I have noticed the mosfet will be on when the analog line voltage is greater than 1 volt which is equal to 1100 band wide, hence I used a voltage divider in the way that output voltage always equal to mosfet Vgs, so for 1500 band wide (2.5 volt) need a 1k and a 2.7k resistor.