Questions tagged [polarity]

For questions about polarity considerations in electronics due to circuit components with polarity (e.g., diodes, transistors, polarized capacitors, batteries, etc.), polarity of quantities directional quantities (such as currents, voltages, electromagnetic fields, etc.), polarity symbols, etc.

Polarity is often an issue to consider in electronics since polarity is a property of certain electrical quantities (e.g., currents, voltages, electromagnetic fields, etc.) and circuit components (e.g., diodes, transistors, polarized capacitors, batteries, etc.). Correct polarity is often necessary for electronics to properly function, and circuit designers must often add protection for the possibly of incorrect polarity (e.g., batteries installed backwards).

281 questions
3
votes
2 answers

What is the polarity of this barrel plug with a double circle?

Related but doesn't answer my specific icon: How to tell polarity expected of a DC barrel jack? I have a dell laptop barral plug adapter, and I can't tell from the graphic whether the tip is positive or negative. It looks like the tip has nothing,…
Stephen S
  • 185
  • 1
  • 7
1
vote
2 answers

What happens if I change the polarity of the battery?

Suppose if i charge a capacitor. Now if I reverse the polarity of the battery, how much is the heat produce during that process? My book says as change in energy = 0 (in capacitor) therefore heat produce 2cv^2. Can somebody actually explain me what…
Who
  • 111
  • 6
1
vote
1 answer

Why I don't get horizontally-polarized TVs in the satellite from time to time?

Something like once every 2 days I cannot watch horizontal SAT channels for about a half day. It says "no signal". During this "no signal" time I get very rarely watchable time. Like 1 minute in an hour. The after this "no signal" time ends there is…
ilhan
  • 111
  • 3
1
vote
1 answer

How to check DC polarity using a multimeter

How can we check DC polarity using multimeter? If the DC cable (the positive and negative end) is connected in the cable rack (terminal block) how can one identify which cable is positive and which cable is negative?
user39300
  • 57
  • 1
  • 1
  • 3
0
votes
0 answers

24 V AC circuit for a hydronic space heating system

I just purchased a home with a gas fired boiler space heating system that is split into 3 main zones (3 circ pumps). I am having difficulty getting heat to parts of the house and I want to first make sure there are no wiring errors. The thermostats…
RenoV8
  • 1
  • 1
0
votes
1 answer

Polarity tester for 1V to 60V circuit

I am making a circuit board to test the polarity of the batteries. The batteries will have different voltages from 1V to 60V. I want to detect the polarity with two LEDs. See below circuit diagram I drew. It works, but when nothing is connected…
0
votes
1 answer

AC/DC Power adapter plug: difference between center positive/negative

Why are some power adapters center positive and others center negative (less common, at least around me)? Is there any compelling reason, something that asks for one or the other for different devices? Couldn't they all be center positive as a…
Quora Feans
  • 434
  • 2
  • 5
  • 19