Continuity on 1/8” male headphone plug

[qb748]

Super basic questions.

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?

 

[rjenkinsgb]

There are two earpieces, both connected from one side to the ground (sleeve) of the plug.

The other sides of the earpieces go to tip and ring on the plug.

So sleeve to tip or ring reads through one or the other earpiece, while tip to ring reads through both in series.

 

[Tony Stewart]

https://tinyurl.com/24thlpql

 

[ahsrabrifat]

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.

 

[qb748]

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?

Much love!

 

[rjenkinsgb]

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.