Im messing with testing continuity on various pairs of headphones, in attempt to verify my understanding of basic concepts and connections.
I have a working set of stereo headphones. No mic, just left and right (TRS).
Obviously, I get continuity when i touch probes to tip and sleeve, and then between ring and sleeve. For fun, I probed tip and ring and i get a connection. The resistance is about double that of the previous.
What is going on here?.. how is there a path of conduction?
Measure Tip to Sleeve (you’ll get ~32Ω for typical earbuds)
Measure Ring to Sleeve (should be roughly the same)
Measure Tip to Ring (should be about double, e.g., ~64Ω)
If you gently plug one earbud into your ear, you might even hear a soft pop or feel the movement, indicating current flow through the drivers.
Measure Tip to Sleeve (you’ll get ~32Ω for typical earbuds)
Measure Ring to Sleeve (should be roughly the same)
Measure Tip to Ring (should be about double, e.g., ~64Ω)
If you gently plug one earbud into your ear, you might even hear a soft pop or feel the movement, indicating current flow through the drivers.
i think i do recall seeing tip and ring had double resistance, which told me something gave me hunch that this was supposed “to be,” and wasnt a malfunction.
You talk earbud “popping,” is that cuz dmm is actually supplying a little current to get resistance read? I guess maybe that should have been an obvious phenomena occurring. Honestly, sometime electricity still feels like magic.
Im disappointed I am having hard time visualizing why I get an electric path with tip to ring measurment.
RIDDLE ME THIS guys:
I will put probes up to a plug on, say an office shredder. How come I am not getting continuity? I mean the wall plug that powers shredder. Voltage or current has to flow from wall into shredder… doesnt that by definition imply continuity?!
I tested positive and neutral prongs of my solder station… a Yihua 958d or something… I got no reading but flipped switch on, and got continuity. Why no continuity in shredder?
I also have 12v computer fan dad had layin around. Just red and black wires coming from it. How come no continuity when I probe wires?
Some devices feed power to rectifiers or active components, which either do not conduct until more than a certain voltage is present (like around 1.2V for a simple bridge rectifier) or need enough voltage for the control circuits or PSU to "start up" and actively control the main power.
A typical device with a switched-mode power supply may have a bridge rectifier plus a high value resistor feeding the start-up circuit, that in itself will not take current until some significant voltage is present - rather more than a multimeter can provide.