Comment on help needed to understand this diagram of a water flow sensor (from a boiler)
diyrebel@lemmy.dbzer0.com 2 months agoIt shows 5V on the diagram but I don’t think that’s precise. I measured the red wire at 4.68v which is around what the guy in the video got in his test. Since the board is part of the circuit I suppose I cannot rule out the board as a problem. Testing the sensor in isolation will be rough going because it’s a proprietary joint. So I would have to get a tight rubber hose and fit that onto a garden hose. For powering it I have a switchable ac adapter with a 4.5 V setting. Or I can maybe get 5V off a USB charger or ATX PSU from a PC. My multimeter does not have a frequency function but I can see from the video that it would be useful for this so I might look for 2nd hand multimeter at the next street market, though that will set me back a week (OTOH might be worth it if it helps diagnose this in a way that helps avoid buying the wrong part).
My money is on faulty controller at this point, but I think you’ll need to find someone with electronics chops if you want to avoid just buying parts until it works again.
For what it’s worth, I didn’t mean take the sensor out of the wall, but just electrically unplug it from the controller to see what it does on its own when you turn on the water.
For what it’s worth, I didn’t mean take the sensor out of the wall, but just electrically unplug it from the controller to see what it does on its own when you turn on the water.
Yeah I figured that but the terminals on the sensor are hard to reach so I was figuring I would need to remove it. But then it occurred to me that I could leave the thing in place and do the isolated test by unplugging the X2 connector from the motherboard and easily access the pins through that connector. So that’s what I did. Results:
So in isolation the sensor worked correctly. Then I plugged it back into the motherboard and retested to confirm again the bad voltages. But in fact the readings were correct. It’s unclear why it works now. I wonder if the unplugging and replugging of the x2 connector improved a connection that deteriorated somehow.
Thanks for saving me €36! However incidental. If I had not done the test in isolation, I probably would not have messed with the X2 connector. I would have normally just replaced the sensor as an experiment.
Good job troubleshooting.
tofubl@discuss.tchncs.de 2 months ago
5V or 4.68V input isn’t meaningful. The sensor has some input range and 4.68V most definitely falls into that. Could be a design choice that has no real implications.
On the other hand, if the device normally supplies 5V, just yours doesn’t, then that’s further evidence you have a faulty controller.