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.
273
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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 ...
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2
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371
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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 ...
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2
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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 ...
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2
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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 ...
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1
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79
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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 ...
- 299
2
votes
1
answer
119
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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?
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2
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63
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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 ...
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1
answer
113
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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 ...
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1
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63
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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 ...
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1
answer
69
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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 ...
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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 ...
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3
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473
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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? ...
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2
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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 ...
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6
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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 ...
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1
answer
213
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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 ...
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3
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349
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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?
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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.
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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 ...
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2
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103
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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. ...
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3
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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?
...
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2
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293
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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 ...
user220456
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2
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148
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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 ...
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2
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761
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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 ...
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2
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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 ...
0
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0
answers
66
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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 ...
0
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1
answer
128
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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 ...
0
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2
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91
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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 :
...
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2
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4
answers
943
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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 ...
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3
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249
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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?...
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2
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521
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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 ...
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3
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146
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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 ...
0
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1
answer
616
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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 ...
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1
answer
119
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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 ...
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2
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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 ...
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579
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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 ...
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397
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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 ...
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1
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407
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What does it mean to say that it has "opposite polarity"? Furthermore, what is meant by "isolation of the input and output ground references"?
I am currently reading the textbook Fundamentals of Power Electronics, third edition, by Robert W. Maksimovic and Dragan Erickson. In the introduction, the authors say the following:
In a dc–dc ...
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1
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Li ion battery polarity [closed]
For a Li ion battery showing 0 volts, should the negative connector from the charger go to the pin with 444,000 ohms or 362,000 ohms relative to common lead from a multimeter that was in contact with ...
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1
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141
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How can I determine the polarity of an unmarked dc input?
I have a portable television with only a 12 volt input. The power lead is missing, which is not really a problem as long as I can identify either positive or negative. The socket is approximately 10mm ...
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1
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188
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Putting AC across polarised capacitors in headphone amp?
This circuit is from Fig. 20.3 in Douglas Self, Small Signal Audio Design, Third Edition, Routlege, 2020.
This is a headphone amplifier, and as such, both input and output signals are alternating ...
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3
answers
118
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AC circuit working principle
When a power source is AC (alternating current) one is a phase and the other is neutral.
Does phase and neutral lines change their polarity over time or only phase line voltage and current up and down ...
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3
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271
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Does a signal that doesn't change polarity charge a capacitor?
I'm wondering if a digital signal that does not change polarity charges a capacitor.
If the signal has a frequency of 1 MHz, does that charge the capacitor faster? And if so, is it possible to ...
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Polarity of inductor in GNSS antenna design
I was assembling a PCB today which had a circuit to connect the main module to an active GNSS antenna. I noticed that the inductor, a 47nH datasheet, had polarity markings on it, but I was unsure the ...
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Why is this 3-way speaker wired this way?
I found a service manual of a pair of 3-way speakers that were part of a mini integrated stereo system. These are Sony SS-H77 speakers, which have served me very well back in the day.
Looking at the ...
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2
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Peltier reverse polarity
I am thinking about using peltier for both heating and cooling to maintain desired temperature profile in small area (2ft square at max)
Can continuously changing polarity damage peltier module and ...
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1
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181
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Tantalum capacitor reverse polarity
I have a datasheet for a part (TPS6735IDR) that shows application circuit examples where polarised capacitors are connected the wrong way around (positive terminal to ground). I thought this would ...
1
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1
answer
195
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Left and right circularly polarized antennas - which one to choose for reception-emission?
I've read that the spiral antenna is circularly polarized, either right or left circularly polarized, depending upon the construction.
I want one antenna be the emitter, and the second one be the ...
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163
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DPDT Polarity Switch
I am trying to connect a USB relay to actuator, so when I press button 1 , motor goes up, when i press button 2, polarity is switched and motor goes down.
I am trying to achieve this with a DPDT relay....
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Can C3 in the schematic be polarized?
Here's the data sheet if it helps.
https://www.cui.com/product/resource/pdqe15-d.pdf
The DC\DC converter is an isolator unit so the left part of the circuit doesn't us a traditional GND, which leads ...
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1
answer
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10000 km Radio Polarization
If someone were to transmit short wave "Skywave" from the equator in the UTC+0 timezone (Greenwich Time) with vertical polarization, and the receiver is at the equator ~10000km away in the ...
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