2 How to test continuity on these particular cables?
Hi all,
I have 4 or 5 of these black boxes in this sewing machine. I'd like to test the continuity of the cables with my multimeter, is that possible? The cables seem sealed inside the black box.
The boxes seem to contain sensors, is that correct? They are all positioned in the machine so that moving parts travel between the boxes' 2 "columns".
I tried looking for the name and info about these but couldn't find any, also tried Google Lens and searching the part numbers written on them but no luck.
Thanks! Any help much appreciated
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@rosalindwyatt sure looks like some sort of speed or timing sensor. Do you have a couple of make and model numbers of the sewing machines where these are out of? I wonder if we are going to have better luck trying to find schematics on those then just the part itself.
I wonder if the iFixit textile Guru @mariaparker can shed some light on this. After all, it's a sewing machine. Shouldn't be rocket science ;-)
Those two slots on the Sharps65 make it look like it is possibly an IR speed sensor. If it is a speed sensor then measuring the continuity may not work. You would have to be able to measure frequency in Hz or if the sensor is powered, you could check the voltage and see if that changes with increased speed etc. For that we would need to know how it is connected to the sewing machine I think on oscilloscope may be a better testing instrument for this....Okay, it may just be rocket science.
por oldturkey03
@oldturkey03 Thanks so much for your reply! What you said makes total sense! I re-checked the service manual and actually it does say the top one I'm holding (Sharps) is the buttonhole sensor. It wouldn't be testing speed in that case, I'm guessing position?
The other one that is actually labelled in the manual, is "upper shaft position sensor".
The 3 remaining sensors are on the gears of 2x stepper motors and 1x on the fan of the Universal motor.
All 5 sensors have those 2 slots in the pins.
I only have a multimeter and my electronic knowledge is almost nil :D
It doesn't matter really if I can't test the sensors, I just wanted to try if I could, to make sure I've tested everything I can with my limited equipment.
The machine powers up, but does not respond to the foot controller. I've checked the foot controller, internal jack, motor continuity, all the other cable continuity. I think it must be a capacitor but can't check unless I desolder I think :)
por Rosalind Wyatt
Here is the service manual, FWIW. It's an Elna 6004 sewing machine, manufactured by Janome. Link here is to wiring diagram
https://www.manualslib.com/manual/912164...
por Rosalind Wyatt
@rosalindwyatt I am intrigued by the level of sophistication of a sewing machine. I honestly would have never expected that type of sensor. Let me see if there is anything out there about the actual type of sensor, may it be Hall sensor or IR etc. The type of sensor will dictate the tools required to check them
por oldturkey03
@oldturkey03 Thank you, I really appreciate you taking the time to help me with this. This machine is only about a mid-range model in terms of computerised sewing machines, so I have no idea what are inside the real top-end ones. This one says it has AI, haha wow
https://www.sewessential.co.uk/husqvarna...
por Rosalind Wyatt