Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [gdt]

17 questions
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Polarity of gas discharge tubes

Do gas discharge tubes used e.g. for surge protection have a polarity, i.e., do they protect in both directions (i.e., depending which wire is hit, or if it is a positive/negative lightnings? The symbol (see below, from Wikipedia) has a dot that…
Martin
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Protecting circuit input against lightning - how to put all the pieces together?

I am designing a single wire (ground return) telephone for use in our hobby caving expeditions, starting out from a well known and successful design called Michiephone (http://speleonics.com.au/business/michiephones/images/mph_schem2.jpg). Here is…
Mateusz
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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 MOV specification is missing. In my current…
prasimix
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How does this surge protection circuit work?

I was searching for a simple surge protection circuit and came upon this schematic (image below) at rs-online blog. It seems there is no description for that specific circuit and it's rather a general advice on surge protectors. Here it is: While…
Tirdad Sadri Nejad
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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 in series? What's the purpose of the 0.01uF…
diverger
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Right wiring for 3 phase 4 wire surge protection devices

I am looking for commercially available SPDs and came across two different options: Option - 1: Return path is earth and there is an MOV on all the lines. Schematic would look like this: Option - 2: Return path is neutral. There are MOVs between…
Whiskeyjack
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How to "drive" a gate drive transformer from complementary PWM outputs of a microcontroller?

I am currently using PWM and MOSFET driving like this. T1 is a gate driver transformer (GDT.) T2 generates high voltage. Now I am planning to replace the SG3525 with a microcontroller which works on 5V. The PWM output will have only 5V and moreover…
UB_Roy
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Two Gas Discharge Tube in parallel; a fast acting gas acting tube and a gas discharge tube

I want to know what happens if we put two gas discharge tube (fast acting GDT and a GDT in parallel), and a tvs diode in parallel. Would there be an issue in putting GDT in parallel? Datasheet of Fast Acting GDT Datasheet of Second GDT
Sam Shurp
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MOV failures in DC

We are facing an issue in our protection circuitry. For the below DC design MOV between Earth is getting damaged in the site. MOV 2 & MOV 3 in the circuit is failing in the site. System is powered from UPS with Centre point earthed. MOV is having…
Akhil Joy
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gdt and mov surge protection

greetings fellow engineers, i came by to ask you for help, i'm building a circuit that needs to be as resistant to surges as possible. I did my research, and make to this circuit: as it is supply by 110v ac single phase, it can be influenced by…
luis felipe Cardoso
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Gas discharge tube and IEC class II device

I'm looking at a design for a IEC class II device, and can see that there is a Gas Discharge Tube being used for suppressing high voltage transients/surges. Since the device doesn't have an earth return, my gut reaction is that this is not a good…
milambergt
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I am failing to understand the difference in Impulse Sparkover voltage vs DC Sparkover voltage of GDT

Lets say I want to use a Gas Discharge tube for indirect lightning protection, and I have a tvs diode in parallel with GDT. Since this is indirect lightning and has a fast waveform, should the tvs diode be slightly above the Impulse Sparkover…
Kasap23
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GDT in parallel with TVS diode. Should the clamping voltage of the TVS diode be equal to the DC breakover of GDT?

I am putting a GDT in parallel with TVS diode, and I want to know if I need to have clamping voltage of TVS diode slightly higher than DC breakover voltage of the gas discharge tube OR have clamping voltage and DC breakover voltage the same.
Kasap23
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Gas discharge tube datasheet impulse sparkover specification

What does the Impulse Sparkover at 100 V/us and 1000 V/us mean? Does it have anything to do with arcing? How does the impulse help us decide with which GDT to choose?
Sam Shurp
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Use GDTs or MOVs under low frequency over voltage protection

For power current transformer, the secondary is not allowed to open when the primary is conducting current of several KAs. So I want to design a over voltage protection circuit for this situation, when there is over voltage (several KVs), then short…
diverger
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