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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.

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Quasi-polarity behavior of silicon capacitor that then reverses when put in use?

What could cause a silicon capacitor to start behaving like a quasi-polar capacitor? A filter involves two 100pF SMD silicon capacitors(600S101FT250T). Two such filters (for two channels) are ...
James Bowery's user avatar
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2 answers
61 views

Testing to find polarity of PCB power connector

I've got a PCB I ordered from China. It required a 5V input voltage through a barrel jack. The issue is there is no sign showing the polarity (positive or negative center) so I don't want to connect ...
Eokun's user avatar
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0 votes
1 answer
53 views

Test that plug is wired correctly

I am looking to build a tester that is verifying that 12 VDC connectors are wired for the correct polarity. It will have a series of plugs for a wiring harness and a switch for each one with a red ...
Caddrawer's user avatar
0 votes
1 answer
47 views

Is there a shielding difference from switching terminals of an MLCC capacitor?

For electrolytic capacitors, the capacitor has only one working polarity (or it usually will get damaged if reversed). For film capacitors, the outermost metal layers ("left" and "right&...
bobuhito's user avatar
  • 544
-1 votes
1 answer
71 views

Invert polarity of an input

I am hoping someone can help me create a simple circuit to reverse the polarity of an input. Working with two wires, a +12V constant and a -12V which is pulsed (think turn signal light). I need to ...
Briggz's user avatar
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1 vote
2 answers
133 views

Breadboard connection problem

The schematic shown is for an electroscope. {Source of the schematic: https://www.electronicsforu.com/electronics-projects/electronic-electroscope?unapproved=346023&moderation-hash=...
MxDiodePN's user avatar
1 vote
4 answers
148 views

Polarity change circuit - reverse polarity with only one relay

I was looking for a polarity change circuit - (reverse polarity) with a single relay but I didn't find it or maybe I don't identify it, the only thing I've found are with two relays, do you have any ...
Lopez Jonathan Daniel's user avatar
0 votes
3 answers
104 views

Can I control a motor in both directions using two sets of dry contacts

Using a device like a Shelly Uni, which has controllable sets of dry contacts, can two sets of dry contacts be used to run an electric motor in either direction, using only one power source? Ie, ...
Globe B's user avatar
2 votes
4 answers
227 views

Is there a rule for assigning polarities to resistors or is it truly arbitrary?

Sorry if this is a silly question, I'm new to circuit analysis. I'm still rather confused about how you're supposed to assign polarities to resistors in a voltage. I've been told time and time again ...
LostAndConfused's user avatar
-2 votes
1 answer
52 views

Polarity free dc circuit module [closed]

I am looking for a chip or a circuit module in which the output will be dc voltage in certain pins positive + and negative - , no matter how the dc input is connected, normal +- or or reverse -+. The ...
Stefanos Konstantopoulos's user avatar
0 votes
1 answer
169 views

Polarity negative or positive on DC barrel jack?

I have a DC port, can I make it positive or negative inside?
abu abdallah's user avatar
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0 answers
25 views

Polarity Detection on Array Charging System for Autonomous Robot

Array Charging Concept I recently became interested in designing a charging system for an autonomous robot. The key requirement is that precise orientation of the robot is not necessary during ...
RemiFM's user avatar
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2 answers
92 views

Do non-polarized capacitors need to be in any type of orientation?

I have submitted my PCB design to JLCPCB for population. They are asking me if the orientation of my capacitors are correct: My PCB and schematic of it: In the datasheet it states that these are non-...
StealthRT's user avatar
  • 783
4 votes
3 answers
677 views

Flyback Transformer Winding Direction

Looking at the basic Flyback Converter Topology, the coupled inductor polarity should be opposite in order for the circuit to operate properly. However, I am confused on how to implement the correct ...
Gman's user avatar
  • 101
3 votes
4 answers
897 views

Reversing the polarity on a relay

I have a single coil latching relay (HFD2/012-S-L2): + & - to set and - & + to reset. I have a 12 V supply to trigger the relay (via a push-button switch). My question is this - how to get the ...
Dave Lees's user avatar
3 votes
2 answers
720 views

Which side is the capacitor negative on this board? (IO/10 marking)

I removed a capacitor (C1 (400v/15uf) - highlighted in the picture) from this board to test on another board and now I want to put it back but I can't figure out the polarity. The traditional symbol ...
ExpectZomibesBy2020's user avatar
0 votes
2 answers
597 views

Why aren't I getting a voltage reading from my AC/DC power adapter

I am new to electrical engineering. I cut the barrel jack off the end of a 24V DC power adapter, exposing a red and white wire. I'm trying to determine the polarity of the red and white wires with a ...
A__'s user avatar
  • 111
4 votes
2 answers
1k views

Footprint for Electrolytic Capacitor

I plan on using this capacitor on my project: https://datasheet.lcsc.com/lcsc/2209011730_KNSCHA-RVT330UF50V167RV085_C5155333.pdf This is an electrolytic capacitor (this means it has polarity.). The ...
user1584421's user avatar
  • 1,369
1 vote
1 answer
148 views

High voltage polarity inverter circuit

I'm building a cloud chamber which needs to use an high voltage source. I'm using an electric fly swatter circuit which can generate about 4kV. The fact is that I want to use a button to switch the ...
Luke__'s user avatar
  • 309
2 votes
1 answer
418 views

Does USB3.0 support reverse polarity in SSTX and SSRX?

Is it possible to Sawp the +/- pins of SSRX and SSTX to make the routing easier and avoid using vias? Does USB3.0 support this reverse polarity?
Mojtaba Najafi's user avatar
0 votes
2 answers
205 views

Lighting Christmas Village Streetlights with LEDs

I purchased a Christmas village from Walmart on sale after the holiday season (Holiday time 30 piece Mini House Set). The 5 houses take 2x AAA batteries each, but I converted them to DC plugins ...
Sloanstarr's user avatar
1 vote
1 answer
256 views

Testing transformer polarity with a signal generator and an oscilloscope

When using the above test setup to measure transformer polarity, the output on my oscilloscope shows a flat line at 0V, it does not register the waveform from the signal generator. The output on ...
willieb3's user avatar
  • 127
0 votes
1 answer
75 views

AC polarity detection circuitry

The three wires in a marinr 120 VAC shore-power circuit are normally black for power, white for neutral, and green for ground. I’m searching for a circuit that will power an idiot-light in order to ...
brent chalmers's user avatar
0 votes
1 answer
73 views

What is the polarity of a custom power supply? [closed]

I have a custom power adapter (this one), but I do not understand what the correct polarity is, as its tip can be reversed. In the picture I have highlighted the marks in the current situation (so the ...
RDGuida's user avatar
  • 101
1 vote
3 answers
185 views

DC christmas string lights without polarity

My sister was doing an electronics project assigned from school and she was given sets of christmas light-looking bulbs in sockets with two wires sticking out of each. When she asked me for help ( it ...
chill389cc's user avatar
0 votes
3 answers
2k views

Which of these wires is positive and which is negative?

I know that in DC circuits the colour code is often (but not always) that red is positive and black is negative. On this AC mains wiring the wires are blue and brown. Does anyone know which is which? ...
Mito's user avatar
  • 411
1 vote
2 answers
269 views

Can you change the polarity of a flyback transformer by swapping the output pins?

I am using the following flyback transformer from Pulse electronics: I am typically used to seeing the dots reversed on the diagram. For this transformer, would current be flowing out of pins 5, 9 ...
willieb3's user avatar
  • 127
7 votes
6 answers
2k views

Inductor polarity

Let's say an inductor has DC current going through long enough for it to completely build it's electro magnetic field. If the source voltage then goes lower, the inductor will 'use' the energy stored ...
Charles-Ugo Brouillard's user avatar
0 votes
1 answer
329 views

Should a start-stop interrupt positive or negative? (Why?)

This answer shows a "standard" start-stop circuit. I was trying to design my own, and came up with a design that is essentially the same, except that it interrupts negative, with positive ...
Matthew's user avatar
  • 572
0 votes
3 answers
775 views

How to figure out the direction of current and polarity of a circuit element?

How do I determine the direction of current in the boxed region? Also, how do I figure out the polarity of the resistor?
Sathvik R.'s user avatar
-2 votes
2 answers
5k views

Which wire is positive on this audio jack (blue and white)?

Which wire is positive and which is negative on an audio jack wire that I have cut off to do some experimental work? I have searched the internet and a lot of answers contradict each other.
jessica smith's user avatar
0 votes
1 answer
213 views

Understanding which P FET to use for reverse polarity protection

I use a Schottky diode as reverse polarity protection on earlier versions but have decided to change to something more appropriate and energy efficient. The voltage input on the left is a 12-14.8 V ...
robbrown92's user avatar
0 votes
2 answers
224 views

How can I determine polarity requirements for a device that is missing its power supply?

I have a MASSFIDELITY relay, wireless Bluetooth receiver for which the power supply is missing. I found a manual for the device that states it requires DC 5V 1A power, but says nothing about polarity. ...
Dustpan's user avatar
  • 11
2 votes
3 answers
83 views

Can polarity protection circuit be useful for also data transmission?

For example, CANBUS has two transmission lines CAN_HIGH and CAN_LOW. Polarity matters. Would the performance be affected if a polarity protection circuit with couple of diodes would be implemented? ...
alfonso's user avatar
  • 457
2 votes
2 answers
799 views

Ethernet devices polarity reversal support

Does all Ethernet PHY devices support polarity reversal even if its not mentioned in the datasheet? [I mean polarity reversal by swapping TX+ with TX- (Like connecting TX+ to RX- or TX- to RX+). Is ...
user avatar
-1 votes
2 answers
173 views

Does time constant or rise time concept apply in transformers as well? [closed]

I am new to electrical engineering. I have made a transformer where I kept one primary and two secondaries, there's an air gap between the primary leg and secondaries on toroidal core, you can watch ...
Yogie's user avatar
  • 129
3 votes
2 answers
1k views

I do not understand this polarity symbol with 3 circles: positive, round, negative, and no lines

I am trying to figure out what is the right polarity of a power adapter for a small practice amplifier. I know it is 9 VDC and I figured out the size of the plug and I know the wattage needed. I do ...
Freddy Montilla's user avatar
1 vote
2 answers
267 views

Is this the correct way to drive a double coil latching relay?

I have found a double coil latching relay which has the following diagram in the datasheet (http://www.fanhar.com/en/uploads/files/FH44L.pdf) : I am quite confused by the instruction "The common ...
photon-delight's user avatar
0 votes
0 answers
82 views

Determining Polarity Of Unmarked AC Adapter With Voltmeter

I need to replace an adapter that no longer works (for a fibre optic Christmas tree). I do not see any indications for polarity on the adapter (or anywhere else) and I do not have the manual. I read ...
Ken Boone's user avatar
0 votes
1 answer
166 views

Inductor polarity

By looking on the picture of the inductor PE-0402CL470JTT and the datasheet, we can notice a black pole and a white pole for the inductor. Is there any difference between poles? The datasheet doesn't ...
Softcity Seven's user avatar
0 votes
2 answers
102 views

Inductor voltage polarity

I am trying to understand the current direction during non-steady states of inductor. The circuit I am testing is very simple : ...
nikhilelite 's user avatar
2 votes
4 answers
2k views

Difference between phase and polarity?

Long story short, I did a bit of a career change, I'm now doing electrical engineering with an architecture firm instead of embedded systems. So I've jumped from the simple world of DC to the land of ...
audiFanatic's user avatar
0 votes
3 answers
344 views

Unusual Polarity Symbols on Universal Adaptor [closed]

The polarity symbols on my universal adapter look a bit different to ones I have seen. Which setting should I use to power the device shown please, top or bottom position for the switch on the adapter?...
Robin Andrews's user avatar
0 votes
2 answers
839 views

How to determine the voltage output polarity of a power supply

I have a high voltage power supply that can go up to 35000 volt. How do I test to see if the unit is outputting positive polarity voltage or negative polarity voltage ? What is the difference ...
Lynn1000's user avatar
1 vote
3 answers
175 views

Show polarity of magnetic pulse using two LEDs

I have made this simple circuit: In response to a rapidly changing magnetic field (pulse), the LED blinks. An example of the pulse is shown below: Now I would like to have a circuit with 2 LEDs so ...
Rasmus Friis Kjeldsen's user avatar
0 votes
1 answer
1k views

Is there a way to determine polarity of a DC device that has missing power adapter?

Let's say someone has bench power supply and a multimeter, then is it possible in safe manner without damaging device to use these tools to determine devices polarity? Update#1: In this specific case ...
user2138912's user avatar
3 votes
1 answer
157 views

Determining polarity of high voltage spark generator

I have a piezo ignition spark generator (Gasmate GMPIK-1) and I want to know the direction the current flows. I can't exactly hook it up to my multimeter because the spark only lasts for a fraction ...
Electron-Capture's user avatar
0 votes
2 answers
118 views

Changing the polarity of the transformer on DUT cause voltage offset on DC measurement with insulating amplifier

DUT (device under test) is powered by 230 VAC and for safety we use additional external 230 VAC - 230 VAC transformer (DUT also has its own transformer for buck converting). We are measuring DC ...
mrkefca's user avatar
  • 71
1 vote
3 answers
1k views

Ceramic capacitors soldering "placement/vertical" polarity

I was wondering, since multilayer ceramic caps have layers like this: Image source Aren't they supposed to (for better performance) be soldered on the PCB as the above picture shows aka parallel to ...
Christianidis Vasilis's user avatar
4 votes
3 answers
524 views

Polarity of TVS diode is unclear

I have a question regarding the DESD1LIN2WSQ TVS diode by Diodes Inc. which I want to use to protect some 24V IOs of a microcontroller board. Until now, the TVS diodes I worked with always had the ...
Sim Son's user avatar
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