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Questions tagged [surge-protection]

Questions about protecting electrical devices from voltage spikes.

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2answers
30 views

Surge arrester placement in substation

Is it enough to place surge arrester on the terminals of the transformer in a substation, or every power line entering the substation should have its own?
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1answer
43 views

transient protection for 0.5W laser diode switching driver

I'm some way into a project which involves switching 0.5W laser diodes at 100kHz, with a pulse of around 1us in width. I'm having issues with the diodes (which I don't have a datasheet for) failing ...
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1answer
52 views

How to protect against line transients?

I am designing a circuit that can detect if a cable is connected to mains voltage (e.g. via an external relay or switch). The device will be installed in electric cabinets. The circuit is tested and ...
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0answers
20 views

Surge Protection Device (SPD) type for home [closed]

I live in a place with heavy rains and thunderstorms. During the last rains I had high voltages hit my AC and fry its IC. Neither my circuit breaker or stabilizer helped in protecting the device. That'...
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1answer
143 views

How do I correctly protect my MCU from resetting during a current surge on RF transmission?

I designed a PCB with a SIM868 module for data transmission. On the PCB, the MCU resets randomly on transmission start of the SIM module. On a breadboard setup, it worked just fine, even without caps. ...
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0answers
44 views

Ok so the whole daisy chaining surge protectors…how does that apply to Whole House Surge Protector and your plug-in into the wall surge protector? [duplicate]

So it's against the fire code whatever code to daisy chain surge protectors but what happens if you have a whole house surge protector wired into your panel and then you have a surge protector ...
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0answers
43 views

Why can't I piggy back / Daisy chain surge protectors or a surge protector and an ups? [duplicate]

Assuming I don't exceed the wattage rating of the whole system then why can't a piggy back let say ups to a surge suppressor in order to let say increase the protection of my system. Let's assume: I ...
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2answers
74 views

Why the replacement of 7812 with R-78E12-0.5, DC/DC makes the circuit not working?

I have this simple surge protector and soft start inside the PSU. My transformer is out of its specifications yields 21.3V after bridge rectification. And 0.1A load (12V fan for cooling pass ...
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0answers
23 views

Medium Voltage Synchronous Motor Protection [duplicate]

How is the wound field of a medium voltage synchronous motor protected from voltage surges? We do know that the stator is protected from surges by either one of the following: 1. RC Snubber Circuit 2. ...
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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 ...
3
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1answer
98 views

How do select capacitor for 400A surge currents?

I have a 220nF capacitor in a series with my surge protection circuit. As can be seen from my spice simulation, the capacitor gets a surge of current passing through it under fault conditions, and ...
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1answer
112 views

Purpose of backup fuse in SPD

I am trying to understand the main purpose of backup fuse used in SPD (Surge Protection device). Is this used to protect the SPD from high AC current but still allowing surge current to pass or does ...
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1answer
176 views

On a wire designated as '3x14AWG' what does the '3x' part mean?

On a wire designated as '3x14AWG' what does the '3x' part mean? It is on a wire that is part of a surge protector power strip.
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4answers
3k views

Is it Safe to Plug an Extension Cord Into a Power Strip? [closed]

Just a bit of context, I am a technology enthusiast. I love everything from software to hardware, Windows to Linux, Computer to Phone, and everything in between. So, I wouldn't be surprised is my ...
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0answers
61 views

Protection against ESD/EFT/Surges

One of my project architectures looks like this: GPIO / 595 output / 12 VDC wire lengths will not exceed 25 cm. I have faced MCU lockup issues due to EFT in the past and want to make sure this ...
2
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3answers
114 views

Surge Current on PCB

When designing a PCB, do you need to worry about the inrush/surge current or just the continuous/RMS current on the board? Everything I have seen including IPC documentation is for continuous current....
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1answer
55 views

Home voltage stabilizer circuit

I am designing a 12000W voltage stabilizer transformer. I saw in another design that they use on the AC neutral a 10W resistor linking on the branch on relay contacts so that the neutral is taken from ...
0
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1answer
64 views

How can I simplify my design for a Surge Protection Device (SPD)?

I have found a basic design for a SPD and I would like to simplify it. However, I have little experience designing SPD circuits. This is my parallel type SPD circuit with embeded LED indicator: In ...
5
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1answer
165 views

230VAC dimmer MOSFET failure at surge test

Our dimmer prototypes work fine, but fails surge test, as per 61000-4-5, 1/50us. Circuit is isolated dimmer for 230VAC different types of bulbs. It uses 2x N MOSFET as switch. V503 detects zero ...
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1answer
35 views

Power strips show fault in some outlets but not others

I'm not sure if this is on topic or not, but I thought I would ask. I have a few power strips (surge protectors) in my house that I use for computers, TV, etc. Some of these have a "fault" or "surge"...
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2answers
127 views

How does diode clamp protection work?

I am not able to understand how diode clamp protection works. Considering the diode clamp protection as shown in Figure 1: When the input voltage (Vin) becomes more than power supply voltage (Vss = ...
2
votes
1answer
49 views

Circuit protection component arrangement

I was reading this thread and decided that in general it's better to place the reverse polarity protection diode D2 after the TVS rather than before it, and to instead use a bidirectional TVS for D1 (...
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2answers
44 views

i dont want to change voltage but only regulate input voltage

It is my first power supply project. I will supply 300 watt vehicle audio amplifier with this supply. I will use nominal 24V and 14A at my system Vehicle input 24V and my amlifier 12V-30V but when i ...
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2answers
134 views

TVS diodes for Ethernet/PoE?

I am getting confused in selecting TVS diode for Ethernet Interface. Should I connect one bidirectional TVS diode across a ...
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1answer
96 views

Separate ground for gate opener control box?

Is it worth electrically isolating the control box of a gate opener from a well grounded steel fence? Or does the grounding of the fence have the same effect? My house is in a very lightning prone ...
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0answers
41 views

Lower VPR in SPD (Surge Protection Device) is more protective?

If you have a universal power supply that can accept 88v to 264v connected to expensive security system. Isn't it if you use a 120v SPD (Surge Protection Device) with VPR (Voltage Protection Rating) ...
2
votes
1answer
93 views

Interpretation of EN 61000-4-5 Surge requirement on a DC Power Port

I am trying to understand how to treat the DC power port on my industrial device (read: will be used in CNC machine shops and industrial processing plants and the like) should be tested according to ...
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2answers
35 views

Using Belkin 6-Outlet Surge Protector in Morocco without a Converter [closed]

Morocco uses the 220V/50Hz standard, and I was trying to use the following power strip I bought in the US with only a adapter (no converter): https://www.belkin.com/us/p/P-BE106000-06/ When I ...
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1answer
104 views

Can car alternator back-emf damage electronics?

I know on startup a motor or generator produces back-emf and current ( correct me if I'm wrong, been a while since I've worked with electric machinery ). Thus, it'd be reasonable to expect that when ...
0
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1answer
112 views

LTC4366 killing MOSFETs

I designed a circuit around LTC4366 as per the picture below. However numerous MOSFETs have been damaged and become useless. Mosfets used : STH12N120K5-2; IXFT50N85XVH; STW13NK100Z - All are rated to ...
2
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0answers
154 views

MOVs, thermal fuse and thermal runaway behavior

Above picture is that of a Belden surge protector with some kind of cloth covered over the MOV and thermal fuse for isolation to promote more conduction. I don't want to cover the whole thing with ...
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1answer
48 views

What could be the function of three components of this surge protector?

An SPD module has the following circuit diagram: I'm trying to understand how it functions. I only know the varistor symbol on the left corner I guess it is a MOV and suppresses transient voltages. ...
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3answers
82 views

Surge or other suppressor I can use, to prevent tool blowing fuse if blade sticks [closed]

I want to say up front, that this question involves minor modification (transient surge/current suppression) to the power supply side of a power tool. Usually I'd be the last to do anything like this (...
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2answers
132 views

ESD diode selection based on VCC of the IC

I have a question about TVS diode selection. This kind of question is already discussed in previous questions. ESD Diode - GPIO Microcontroller Selecting a TVS for ESD protection For protecting vcc ...
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1answer
72 views

Is this a Disconnector beside MOVs?

This is inside a power strip surge protector. What is that tubelike thing between the MOVs? Is it the disconnector (written "22IR UMI, 4A, 102 Celcius, 250V")? Can anyone show me images of a ...
6
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1answer
342 views

UL Clamping Voltage Ratings on Surge Protectors

I have been looking for some new surge protectors for my devices, and I am having trouble understanding the meaning of the voltage clamping ratings on many surge protectors. It seems that all of the ...
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1answer
203 views

Calculating energy of transient/surge handled by metal oxide varistors (MOV) or surge suppressors?

As I get to know more about the MOV operation, there are more things needed to understand. My MOV (V420La20AP) has Varistor voltage of 680 Vrms (10%) at 1 mA, and maximum clamping voltage of 1120 V ...
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1answer
260 views

What is Metal Oxide Varistor (MOV), meaning of its specification and how it protects circuit from over-voltages?

Hello, I have a circuit in which a voltage source is connected to some sort of RC Load. To protect this circuit , there is an Metal Oxide Varistor (MYN15-681K). The Pics of circuit and datasheet ...
2
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0answers
76 views

High power / high current clamping circuit

I am looking for ideas on how to clamp high energy surges in the input of a high current / high power system. The input to the system is 24V. During steady state, the system sources 85A of current ...
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0answers
93 views

Surge Protection for Optocoupler

Resistor Specification Edited: 24July18 Does the TVS + Zener diode provide adequate surge protection to the opto from voltage spikes and indirect lightning hits? The resistors are smd type with ...
2
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2answers
728 views

Auto turn off switch during power outage

In my area power outages are a daily routine. And power surges, which occur when the electricity comes back, makes it even worse. To avoid damage of the electronic devices we try to unplug them ...
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0answers
27 views

Power Outages and Surges

I live in South Africa where we experience frequent power outages due to so-called "loadshedding". With this, there have been numerous cases of damage to appliances due to surges, usually when power ...
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2answers
152 views

What kind of protection do these Ethernet “surge protection” diodes provide?

I was considering a network run outside of my home, and purchased a super-cheap "Ethernet Lightning Protector" because there was little to lose, and I wanted to understand its workings. Below you can ...
2
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1answer
74 views

Can someone explain the working of this Surge Suppression Circuit

This is an old circuit which is still being used. I am curious to understand that if 600 VAC is applied to AC side of the three phase rectifier which has diodes, and on the DC output side of the ...
0
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2answers
88 views

Automatic cut mains power on a thunderstorm

I am a software engineer with only a basic experience with electric/electronic engineering. I live in a rural area subject to thunderstorms, my house is the end of the line from street poles. It's ...
3
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3answers
239 views

History of ESD protection

These days you can't read anything about electronics without hearing about the dire consequences of omitting ESD protection from your designs. It seems this wasn't always the case. If you look at ...
2
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2answers
336 views

overshoot and undershoot on 3 volt pulse

i am interfacing a system, this system output signal of 200ns digital pulse with repetition time of every 3ms. Ideal voltage of signal would be 0v to 3.3V but signal coming from system have high ...
2
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2answers
272 views

Lightning protection for underground loudspeaker wires

I am tasked with running a loudspeaker to a remote building. The total run length is around 275 feet, with the outdoor portion being around 165 feet. The cable is Cat5e 24awg unshielded, silicone ...
4
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2answers
2k 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 ...
3
votes
3answers
117 views

How to protect againt surges if working and maximum voltage are too close

I have a circuit that I want to protect against surges and eventual peaks (e.g. indirect lightning surges) and I was thinking about TVS diodes or MOV. The situation is: -My circuit input is 48V that ...