My question is what did I do wrong that caused my Discovery BNC to go up in smoke?
I was trying to measure a millivolt signal generated by an abs sensor on a car. I was not receiving any signal after testing several sensors. After double checking settings, I wanted to verify that the oscilloscope function was working at all so I connected the test leads to a 12v car battery. I did see the 12v signal on the scope, however the leads became untouchably hot almost instantly.
I then looked up the internal resistance of the analog discovery 2 (1M Ohm) and confirmed this resistance using my multimeter. Touched the oscilloscope leads to the battery again and they heated up instantly.
I then ran the scope in series with the amp meter in the multimeter. It read 0.001V and there was no excess heat generated on the scope leads. I found this very strange and decided to try the scope directly to the battery one more time and this time a circuit on the Discovery BNC overheated and burned the board.
I don't understand why this happened. I have always tested the scope with a direct connection to a 12v DC source for long periods of time and have never had an issue before. A 1M ohm resistance on a 12v circuit should be a very safe current. I'm open to any thoughts! Thank you. Doug
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weaverdouglas22
My question is what did I do wrong that caused my Discovery BNC to go up in smoke?
I was trying to measure a millivolt signal generated by an abs sensor on a car. I was not receiving any signal after testing several sensors. After double checking settings, I wanted to verify that the oscilloscope function was working at all so I connected the test leads to a 12v car battery. I did see the 12v signal on the scope, however the leads became untouchably hot almost instantly.
I then looked up the internal resistance of the analog discovery 2 (1M Ohm) and confirmed this resistance using my multimeter. Touched the oscilloscope leads to the battery again and they heated up instantly.
I then ran the scope in series with the amp meter in the multimeter. It read 0.001V and there was no excess heat generated on the scope leads. I found this very strange and decided to try the scope directly to the battery one more time and this time a circuit on the Discovery BNC overheated and burned the board.
I don't understand why this happened. I have always tested the scope with a direct connection to a 12v DC source for long periods of time and have never had an issue before. A 1M ohm resistance on a 12v circuit should be a very safe current. I'm open to any thoughts! Thank you. Doug
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