In my project I am using a Teensy 3.6 in an automotive environment (I know perhaps not the ideal choice).
With the knowledge I have I have tried to implement all kinds of protections.
Nevertheless have I destroyed two Teensy's already.
In both occasions I accidentally shorted a 12V wire somewhere in the car and that has blown the fuse for that circuit.
At the moment I don't really understand why that is happening.
A bit of information about the context:
- There is one input from the 12V system going into the Teensy which is whether the ignition is on or not, but that is via an Opto so I'd say that cannot be the cause.
- I am using a Traco TSR-2-2450 to power the Teensy, there is no TVS in place to protect the Traco.
- In total there are two Teensy's, one "always on" and the other on when my battery management system is on. When I caused the short only the "always on" was powered but the "bms on" Teensy got fried
- There is an opamp that is connected to DAC0 to create a 0-5V output signal
- I am powering the Vbat of the "bms-on" Teensy with the 3.3V out from the always on Teensy
My hypothesis is that the "bms on" Teensy has tried powering the 12V after the fuse blew.
I have checked a Traco (TSR-1-2450E instead of TSR-2-2450) and when I put 5V on what normally is the output I am measuring 4,5V on what normally is the input.
But when checking whether the Teensy gives an output voltage on the Vin pin when Vb is powered with 3,2V that was a negative.
So now I'm still not sure what has happened.
Looking forward on hearing your thoughts on this.
ps. Don't want to overload the forum with too much details of my project but am happy to share more for a possible better understanding.
With the knowledge I have I have tried to implement all kinds of protections.
Nevertheless have I destroyed two Teensy's already.
In both occasions I accidentally shorted a 12V wire somewhere in the car and that has blown the fuse for that circuit.
At the moment I don't really understand why that is happening.
A bit of information about the context:
- There is one input from the 12V system going into the Teensy which is whether the ignition is on or not, but that is via an Opto so I'd say that cannot be the cause.
- I am using a Traco TSR-2-2450 to power the Teensy, there is no TVS in place to protect the Traco.
- In total there are two Teensy's, one "always on" and the other on when my battery management system is on. When I caused the short only the "always on" was powered but the "bms on" Teensy got fried
- There is an opamp that is connected to DAC0 to create a 0-5V output signal
- I am powering the Vbat of the "bms-on" Teensy with the 3.3V out from the always on Teensy
My hypothesis is that the "bms on" Teensy has tried powering the 12V after the fuse blew.
I have checked a Traco (TSR-1-2450E instead of TSR-2-2450) and when I put 5V on what normally is the output I am measuring 4,5V on what normally is the input.
But when checking whether the Teensy gives an output voltage on the Vin pin when Vb is powered with 3,2V that was a negative.
So now I'm still not sure what has happened.
Looking forward on hearing your thoughts on this.
ps. Don't want to overload the forum with too much details of my project but am happy to share more for a possible better understanding.