My diodes arrived...

I’ve been making a circuit that lets a Raspberry PI PICO ring an old style telephone bell. Yesterday I discovered that voltage pulses generated in the coils that power the bell were destroying the MOSFETS that I was using to control the power. Today I got some diodes that I was able to fit across the coil connections. Now the bells ring out loud and clear. It’s so loud you can hear it next door. Which might not be a good thing.