Questions tagged [varistor]
The varistor tag has no usage guidance.
52
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Relay for rollershutter motor
A few years ago, I build a controller for our garden door rollershutters (2x 2m wide), 230VAC 2xL-N controlled. In some initial tests, the inductive load killed the cheap mechanical relays found on ...
-1
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1answer
51 views
Why does the high capacitance of a metal oxide varistor affect sensors and signal sensitivity?
I want to know why the high capacitance of metal oxide varistors affects sensors, signal sensitivity.
How does capacitance affect sensitivity ?
If we add a low capacitor in series will the total ...
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0answers
39 views
Can we use tvs and mov together for thruster?
I want to know if we can use both tvs and mov varistor together ?
What will be good for thrusters ?
And placement between esc and thruster or before esc?
Update:
system voltage is power supply ...
0
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1answer
32 views
Why often is used a varistor 7D471K for 220-240vac surge protection rather than a lower nominal voltage one?
In my "supposedly" surge protected power stripe there is a varistor for surge protection configured to simply short-circuit the entrance wires in case of surge.
Checking the model it's a MOV-7D471K ...
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1answer
35 views
Varistor in a DC circuit
I'm employing a Varistor in a simple circuit that will be used in a car. The Varistor is there to ensure that any load dumps / vehicle transients will not result in catastrophe for the circuit.
My ...
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1answer
30 views
Calculation of varistor parameters for AC line protection
There is a task to choose a varistor to protect the AC circuit, controlling several coils of magnetic starters.
Characteristics:
Mains voltage 230-240V AC
Frequency: 50Hz
Starting current of coils ...
1
vote
1answer
51 views
Identify unknown disc-shaped component - markings include VF10 0471K
I am trying to identify this piece, which I believe is a varistor, though I'm not sure. It comes from a Samsung rice cooker. I have attempted numerous google searches on the markings, but I have so ...
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1answer
81 views
Are external components required for HLK-PM01?
Apologies in advanced as this is kind of a vague question and due to my lack knowledge in this specific sector. I'm designing a circuit using a HLK-PM01 as the power supply which is a 3W AC-DC ...
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1answer
135 views
Placement of varistor with respect to fuse
My design includes a pretty standard AC/DC converter powered by mains for intended use at home. For overvoltage and overcurrent protection, I am planning to use a combination of varistor and fuse ...
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1answer
91 views
Trying to ID this component & where to get a couple of them? Is it a varistor?
Here's a photo I made to show back and front of this thing.
I think it's a varistor.
The main body is roughly 8.5mm in diameter.
I straightened the two legs but I think they are SUPPOSED to have ...
0
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1answer
36 views
Need some help Identify a Varistor
I had a either a surge or a part failure cook a few components on board. The board is rather old from a discontinued product. On the board the only components I've not been able to identify that need ...
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3answers
2k views
Varistor? Purpose and principle
In the AL9910 LED driver datasheet it shows a part, which I assume is a varistor, is it so? Varistors are shown to be connected across L and N lines, but here it is connected in series. Please explain ...
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1answer
198 views
Creating a temperature-dependent solar cell in LTSpice (using varistors)
I'm currently working on my master thesis and therefore need to simulate a solar cell in LTSpice.
I've already modeled and simulated some examples with constant values. But for a more accurate model, ...
2
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2answers
123 views
How much buffer room is required for a varistor?
I am working on a circuit board design that uses a fuse resistor for protecting from short circuits and a varistor to protect from over voltage. The board is a simple power supply of only a few watts.
...
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1answer
96 views
What is this solar power RC circuit doing?
I am a CSE student working on a project.
We are using a solar powered microcontroller. The solar panel's power goes through a fuse and an RC circuit with a varistor to the charging system.
What ...
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1answer
400 views
Why does my varistor cause my fuse to blew up?
I have made the following circuit (copied from a very similar picture on internet):
At one side of AC/DC I put a normal fuse.
The MOV is a 14D391K 14K391 390V varistor diameter 14mm AC 250V DC 320V ...
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2answers
2k views
How can I compare a TVS diode with a varistor?
For a 120Vac line protection element, comparing this TVS diode:
With this varistor:
The immediate differences I see are:
The varistor is marginally cheaper
The varistor specifies a maximum working ...
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1answer
168 views
Can Orcade (PSPICE) actually simulate MOV(Varistors)?
I am using Cadence-Orcade Lite. In it I have a circuit in which I want to note the behaviour of varistors (MOV, PSPICE models exist in Orcade for various varistors).
I am using LS40K680QP/EPC Model ...
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0answers
386 views
Power Supply Fuses and Varistor
I wish to build a little decent power supply for my IoT devices, would like also to implement more protection from the live 230V AC side and I decided to put a fast blow glass fuse in a nice holder, ...
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1answer
138 views
Help with identify varistor
Need help identify this varistor. Been trying to figure it out since 5 pm of yesterday. Cannot find anything on it. Any help is greatly appreciated.
5
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2answers
888 views
Help identifying a varistor?
Need help identifying a component that I think is a varistor. It is burnt so it appears black. The circuit is part of a control module for the headlights and keyless entry on a Lincoln. I want to ...
0
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1answer
68 views
Discharge of a coil powered by parallel transformers
I have the following circuit:
I basically have 2 transformer, one is 230V-8V the other one has a ratio of 1:1, so 230V on the secondary.
I'm rectifying the two signals with two full bridge ...
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3answers
447 views
Maximum fuse rating before a MOV (varistor)
I just watched some scary videos of MOV's catching fire and I've flee'd here to ask you guys for help.
I understand that it's a good idea to put a fuse in front of a MOV, considering it fails short-...
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1answer
558 views
AC/DC power supply: help to choose fuse, varistor and/or TVS diode
I'm going to use this 12VDC AC/DC power supply . It is the first time that I am going to use one and I have some questions about over voltage protection and peak current protection. These are the ...
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1answer
1k views
Identify Varistor TVR 20471
I got this broken Varistor from an Eaton3S 550VA 300W UPS.
Marked TVR 20471*
I have tried my best to find a replacement but I can't find a similar one. Any tip or recommendation for a similar one ...
5
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2answers
4k views
How to choose the right Metal Oxide Varistor (MOV)
I would like to protect the input of a transformer against high voltage surges but I don't understand how I have to proceed to choose the right MOV despite what I read so far about them.
Below is how ...
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2answers
859 views
Is a varistor basically two diodes in series, with opposite polarities?
The typical curve for current vs voltage for a varistor:
looks a lot like the 2 reverse voltage regions of a normal diode:
Is this equivalent the following, and if not, why not?
simulate this ...
2
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1answer
265 views
Energy dissipation and current decay in this circuit
I have a circuit that looks like this :
A 200 A current controlled power supplies delivers the current to a coil (with inductance ~ 5 mH) when the MOSFET is open.
The varistor is there to clamp the ...
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0answers
143 views
Trying to identify varistor values off an ancient power supply
Was tricky to get a photo with the markings visible, but as best I can tell the markings read...
H L1
1502
...The scoring down the middle is from where I ...
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1answer
457 views
varistor curve and voltage meaning
Could I get an explanation for these datasheet definitions for a varistor?
1) Max. applied voltage.
2) Min varistor peak volts.
3) Max varistor peak volts.
4) The clamping voltage is known to be ...
0
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0answers
36 views
VI curve varistor and compere between varistor and arrestor
why we need to connect arrestor in parallel with varistor in some circuit ? and we know both is work to protect against high voltage?
like this pic.
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141 views
Blown varistor after connecting UPS?
I have a pellet burning stove and the manufacturer provides for two options for battery backups. One is an inverter and deep cycle battery that can run the device for a few hours, the other is a UPS ...
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1answer
3k views
Does a varistor have anode or cathode or polarity?
Below is a MOV varistor:
Does a varistor have anode or cathode or polarity?
Can I connect the legs in any way or does it have an orientation like diode?
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1answer
161 views
Help identifying Components
I need help tracking down 2 replacement parts.
From what I know they are 1 Varistor and 1 Pico Fuse.
Could anyone confirm that and tell me what I should be looking for to replace them. Googling the ...
2
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1answer
1k views
Is this a varistor?
Can someone id this green part? Z5V 104Z 500V I think maybe it's a varistor (like the blue one in the lower-right of the image) but haven't been able to find a replacement.
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2answers
153 views
varistor with reverse operaton
Varistors are known to use for over-voltage protection, as they have high electrical resistance at low voltage which decreases as the voltage is raised.(wikipedia).
But is there any electrical ...
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1answer
569 views
Should I use both a MOV & a flyback diode for a very high power DC motor (7560W)?
I couldn't find a circuit online that uses both so I figured I better ask those who know more than I do if this would be a mistake or not. Thanks for your help
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1answer
621 views
Does SSR with DC Motor still nead back EMF protection
I plan to use a solid state relay to control a couple of small 12 VDC motors. One is 12V, 12Watt (1A) and the other is 12V 11amp peak. The SSR can handle 15A DC. Some of my inputs (different part of ...
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3answers
4k views
Help identifying a varistor
Hi I am trying to identify what I think is a varistor. The problem I am having is the markings, other than the voltage don't seem to corrolate with anything. So I'm not sure if it is a varistor or if ...
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2answers
1k views
The capacitance parameter in varistor data sheet
What is the meaning of the capacitance parameter in the datasheet of a varistor?
For example: I have noticed that 7mm 430 varistor voltage(07D431K) and 14mm 430 varistor voltage (14D431K) have the ...
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2answers
334 views
How to reduce a pulse voltage maintaining a high impedance?
I have one pulse with 200ns and 60 V. I have to reduce this voltage until 10 V min because of the monostable multivibrator. After this, I will extend the pulse with a monostable multivibrator and then ...
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3answers
5k views
What are some common applications of the MOV? (Metal Oxide Varistor)
The owner of a broken washing machine recently asked me to examine a damaged circuit board he had found inside. Using the schematic I was able to determine that the charred area formerly contained a ...
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2answers
426 views
What kind of elements are these?
I disassembled a LED lamp and it's circuit. My intention is to rebuild that circuit within EveryCircuit app, to understand how it is working.
On this circuit I found two elements that are rising ...
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1answer
213 views
Varistors set to ground or case by isolated ground/case
I have a isolated ground from the case in my device. The Supply Voltage is +24VDC with Ground and separated CASE, so no safety issues.
On any signals coming from the case (Plugs) I put varistors, but ...
2
votes
2answers
3k views
Connecting varistor and surge arrester in series
I have a doubt about proper values of MOV and SAR when they are connected in series as suggested in Epcos app notes (see below Fig. 12). For the 230 VAC mains they recommends SAR of 470 or 600 V, but ...
0
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1answer
120 views
Fuse Question and Surge Protectors
I am doing a DIY PDU project for my college using an Arudino and I have 8 16Amp relays that are controlled via the board. I want to make some sort of surge protector for it as well.
Basically I want ...
5
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1answer
331 views
MOV Characteristics
I need to select MOV for my application.
Vin max=520Vrms
Surge Voltage= 4000KV
as per IEC61000-4-5, 8x20us waveforms.
So my calculation is
$$ \text{Surge Current}={(V_{transient\_max}-V_{clamp}) \...
11
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1answer
2k views
Potentiometer vs Varistor
What is the main difference between and potentiometer, rheostat and a varistor? And how do the application of the three in a circuit differ? Or to be more concise, in a variable power supply why ...
5
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1answer
385 views
What component has the reference designator RY?
I found a component designated RY8015 which I don't recognize, shown on the photo below on an LCD TV PCB (the bulb-like part next to a green radial varistor).
What is it called? What is its design ...
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1answer
2k views
GDT in series with varistor
I often see GDTs are used in series with varistors, like this
E100 is a 1500V/10A GDT, and RV100 is a 1.1KV diode varistor.
For this circuit, I have two question
What's the benefit to combine them ...
