I have had a Mighty Mule FM141 sensor installed for about a year and for the most part it has been working well. But in the last couple weeks I have had a couple short power outages (less than a couple minutes) that have caused the sensor to stop working. I am able to recover by powering down for a several minutes and powering it back up.
I should note that this isn't their current version. I got it new in the box from ebay and it was a few years old at the time. I tested it before installing it in the final location and found that short power interruptions made the device never report a vehicle. I was able to test out a current model about a year ago and it did not seem to have the problem.
The power supply I am using has a hold up time of about a minute due to the low current of the sensor.
On one interruption the output stuck closed, giving a continuous indication of a vehicle instead of a pulse. That was immediately obvious because I have a beeper connected. The second failure just caused the unit to stop detecting cars and wasn't noticed for a while.
My plan is to make a supervisory circuit that detects undervoltage and keeps power off a minimum time (say 30 seconds) before restoring power. I am thinking of using an Arduino as a node for reporting the status of the sensor and could use the Arduino also as a power supervisor.
Just wanted to let others know of this issue, see if anyone else has observed it, and what others may have done to fix it.
I should note that this isn't their current version. I got it new in the box from ebay and it was a few years old at the time. I tested it before installing it in the final location and found that short power interruptions made the device never report a vehicle. I was able to test out a current model about a year ago and it did not seem to have the problem.
The power supply I am using has a hold up time of about a minute due to the low current of the sensor.
On one interruption the output stuck closed, giving a continuous indication of a vehicle instead of a pulse. That was immediately obvious because I have a beeper connected. The second failure just caused the unit to stop detecting cars and wasn't noticed for a while.
My plan is to make a supervisory circuit that detects undervoltage and keeps power off a minimum time (say 30 seconds) before restoring power. I am thinking of using an Arduino as a node for reporting the status of the sensor and could use the Arduino also as a power supervisor.
Just wanted to let others know of this issue, see if anyone else has observed it, and what others may have done to fix it.
