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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How to find Voltage based on reference nodes?
I came across this problem and I'm trying to really understand it.
VB is the voltage drop across a particular element, it is the change in voltage from node a to node b. Find the value of VB in ...
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1
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Troubleshooting why Powerbank Doesn't Charge Cell Phone [closed]
I have powerbank that provides 5v (presumably regulated) power, as typical of most usb interface powerbanks. I have been trying out my powerbank with different phones. It works on all except one. I ...
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Reverse polarity protection
I read somewhere that this can be used for the reverse polarity protection in the circuit. But I am quite confused with its operation. Can somebody help me with this.
simulate this circuit – ...
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2
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Reverse polarity protection - PMOS vs Schottkey diode
I have a circuit running from 2 AA cells in series, meaning I get 3.0V when fresh (or 2.4V if NIMH cells) and it goes down to 2.0V, that's when my circuit cannot function anymore (no DC/DC onboard).
...
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Reverse polarity protection idea
I'm thinking about making a reverse polarity protection for a project. This is for a small line follower robot and I'm still deciding if I need a reverse polarity protection at all.
It will be powered ...
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5
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Aren't non-polarized plugs a little dangerous? Why still use them?
Sorry if there is an answer for this kind of question somewhere. I can't find it anywhere.
Take a look at obvious toaster example:
If you live in Europe and have non-polarized plug and a toaster (a ...
user50786
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6
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In an NMOS, does current flow from source to drain or vice-versa?
In an NMOS, does current flow from source to drain or vice-versa?
This Wikipedia page is confusing me: http://en.wikipedia.org/wiki/MOSFET
The above image confuses me. For the N-channel, it shows ...
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2
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Does MOSFET let current flow through source to drain as it allows it from drain to source?
Does a MOSFET allow current flow in reverse direction (i.e.; from source to drain)?
I made a Google search, but couldn't find a clear statement about this matter. I have found this similar question, ...
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1
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Designing an inverse polarity and overload (crowbar) protection circuit
There are some great resources on the internet and on this site about designing various protection (crowbar) circuits. For example, Leon's answer to a general circuit protection question.
I'm looking ...
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1
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Mesh Current Polarity, Equation Setup
Practicing Mesh Analysis I came across this problem and te answer is really alluding me and I believe is just one polarity that I'm not understanding, the problem is the following...
Vs=10V, R1=...
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How do I decide what capacitor to use in a circuit?
I am using a voltage regulator, and to get cleaner power, the datasheet recommends using a 0.33uF capacitor. However, it doesn't say what type it wants. Stupidly, I ...
- 3,790
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4
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Does an over voltage, over current and reverse polarity protection IC exist?
I'm designing a circuit that has the following protection requirements:
Reverse polarity
Over voltage (60v max)
Over current (approx 1A)
There's quite a large input voltage range, 10v to 60v.
48v ...
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3
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What does the radiation from an antenna look like?
Just out of curiosity, I searched for antenna on Google Images, and what usually shows is something like this. So I really thought that an antenna radiates in a circular and equal pattern. But as I ...
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Is a Schottky diode appropriate for reverse polarity protection?
To narrow the focus a bit from an earlier question:
Is a Schottky diode appropriate for reverse polarity protection?
I'd like to prevent mishaps from a user connecting DC power in reverse, but I'd ...
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9
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AC polarity detection
How can I detect AC 'reverse polarity' (single phase) (without the use of ground/earth) and drive a led when the polarity is reversed?
It should at least detect 230 VAC but it would be cool/...
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Can current flow both ways through a transistor?
Last night I was experimenting with and motors and transistors. I was testing out NPN and PNP transistors to learn more about how they work and how I can use microcontrollers to control the speed with ...
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Does my device need reverse polarity protection?
I'm developing a device with changeable AAA batteries running at 3V. Since the end user can change the batteries there is a chance they may be put in the wrong way around. The circuit basically ...
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Why do we use polarized capacitors?
I want to know if the polarized capacitor has some advantage that they are used in some circuits?
For example, in a schematic of the BISS001 PIR controller IC, in some places, a polarized capacitor ...
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5
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Why don't more devices incorporate full-wave rectifiers as reverse polarity protection?
Recently, I was introduced to the idea of using a full-wave rectifier, in order to protect against reverse polarity damage in DC devices.
I hadn't even considered using a rectifier in an already DC ...
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Is this an AC or DC signal?
My teacher says that this signal is DC, but if the polarity varies from 0V to -8V , shouldn't it be AC?
He says that
DC + AC = DC
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Why does this two terminal inductor have a polarity?
The Murata LQP03TN2N0C02D 2nH 0201 size inductor apparently has a polarity marking on the package:
I don't see anything on the data sheet that suggests there's a difference installing it in a circuit ...
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Are Peltier elements polarized?
I'm looking to add a Peltier element to one of my projects. However, I want to sometimes heat and sometimes cool, depending on the ambient temperatures on both sides of the element.
Image from ...
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SMD LED polarity marking: is the cathode marking standardized?
SMD LEDs normally have some kind of marking like the following image from here indicates:
The site states
The CATHODE lead is always the lead to be identified with ALL LEDs, including surface-...
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3
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LED anvil and post are reversed!
Typically, through-hole LEDs seem to have the cathode (-) side connected to the "anvil" and the annode (+) connected to the "post" (see diagram below).
...But I now have in front of me an LED that ...
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astable multivibrator: capacitor polarization
Looking at this circuit, I'm wondering if the capacitor polarization "+" is correctly draw. Assuming T2 is in cut, T1 is on, left capacitor will have a 0.7v in its right side (connected to T1 emitter) ...
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Change Direction of 12v DC Motor Rotation using Relay
I want to make a circuit to change 12 Volt DC Motor direction and move some thing between two points. Using Relay or some basic limit switches.Like this Image.
I got a Circuit As i want...
AUTOMATIC ...
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Do electret microphones have polarity?
So do electret mics have polarity?
The following circuits seem to contradict each other...
1)
2)
Now the problem is one image shows polarity while the other one does not!!
What's the holdup here?
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Is there a convention for the polarity of voltage specified as \$V_{XY}\$? [duplicate]
Inspired by this answer, which includes the image:
Which solicited the comment:
No, you have the polarity of Vce shown backwards in the diagram [...]
The diagram seems consistent to me: the ...
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rx_polarity inversion in USB3.x
As per USB3.x specification there is provision of
rx_polarity_inversion
can any one exactly says, what is the reason behind it?
Edit:
Normally connection of ...
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Does the input polarity matter for a 12V DC adapter?
I bought a car cigarette DC adapter yesterday with the following specs:
Input: DC 12V
Output: DC 17V
I'm planning to connect it to a 12V battery I have at home,...
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1
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Will an electrolytic capacitor work reliably with 0 VDC and 100 mVAC?
I ran across an instrumentation amplifier datasheet from "THAT Corporation", and noticed the polarized capacitor in series with the gain resistor:
It is a typical 3 op-amp in-amp, so the differential ...
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2
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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=...
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Peltier damage and efficiency when continuously reversing 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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3
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Motor polarity reversing circuit using just SPDT switches
I have a 6v DC motor that controls a physical system similar to a window blind, using one SPDT toggle switch and two SPDT microswitches for control. I have seen similar setups with hoists, however I ...
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Changing the polarity of electromagnet using H-Bridge
I have made an electromagnet using copper coil of 1.0 mm diameter, iron core of 2 cm dia & 8 cm length for my project. Supplied voltage is 12 VDC and current it consumes is 9.0 Amp. It has 1.5 Ohm ...
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Determine Polaritry of Aluminum Electrolytic Capacitor
I have an NIC aluminum electrylytic capacitor and am trying to figure out which wire is positive and which is negative. Forgive me if this is a stupid question since I'm a total noob at this.
This is ...
user25603
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How does the lead polarity work on a D'Arsonval galvanometer?
Following an illustration of D'Arsonval movement such as the following...
I notice that the N polarized part of the coil is connected to the positive lead and the S polarized part of the coil is ...
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4
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Using limit switches to reverse circuit polarity
I am designing a linear translation stage that will be driven with a DC motor. When the circuit is powered the DC motor will start turning in either direction, which will move the linear stage towards ...
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Confused about polarity of Transformer
I am confused about the Transformer dot polarity. I got design from ST's edesign Suite. Here is schematic for that :-
Now I need to order the design for transformer and the transformer design centre ...
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