I have built the below circuit with a breadboard.
The bottom power supplies 5v is supplied by arduinos digital out port for 100ms and then off for 1 second.
The top battery is just a 9 volt battery.
I have an analog read coming from just above the 50 ohm resistor on the very right, and its signal pattern is displayed in the bottom right chart.
Basically, i want to be able to read a stream of voltages as the inductors flyback decays to zero.
The trouble is, when simulating the circuit with my software, using a 400uH coil (which is what i use in the real circuit) decays too quick, in microsecond territory, so i have to use a coil with larger inductance in the sim just so i can see the flyback decay pattern when i turn the circuit off.
Anyway, what would i need to do to make the flyback signal readable by arduino?
I currently recieve 0 when i run it as is so obviously the analogread is too slow to capture some of the flyback voltage.
Any help getting this working would be greatley appreciated.
If i could just take 3 or 4 samples before flyback voltage reaches 0 volts that would be good enough for now.