Questions tagged [surge-protection]
Questions about protecting electrical devices from voltage spikes.
333
questions
3
votes
1
answer
63
views
What to expect from adjusting the suggested EMI filter and surge protection on a DC/DC power supply's application note. 61000-4-5
I am trying to make the CQB50W12-72S12 120VAC input capable by adding a bridge rectifier into the design that is already called out in the application note (app note and data sheet found here: https://...
- 422
1
vote
1
answer
50
views
EN61000-4-5 Surge protection of PCB power supply
I am trying to better understand how EMC testing is simulated and passed. The datasheet of the CQB50W12-72S12 says it pass level 4 line to earth 4kV; and +- line to line 2kV with just a TVS diode (...
- 422
2
votes
1
answer
128
views
X2 Capacitor rating
For a power supply circuit, I need to add an X2 capacitor. I have space constrains - so, considering choosing a very small SMD component.
The product will be connected to 230V 50Hz mains voltage. The ...
- 141
0
votes
2
answers
30
views
How to spec a MOV resistor
I want to add a resistor before my MOV. The largest surge I will have will be 3kV.
I came across this datasheet.
If the most voltage my load can handle is 1kV surge, what will the resistor value be?
...
- 1,865
4
votes
3
answers
835
views
Protecting a circuit when working voltage is close to the absolute maximum
I designed a step down converter using WEBENCH. It takes 8-24V DC input and outputs 5V. The basic design works fine, but I learned from this question about why it died when I connected it to a 24V ...
- 4,560
0
votes
0
answers
46
views
TVS diode to protect 12V circuit
I have a simple 12V circuit with PIR, 555, couple of transistors and an outside 220mA LED light in a circuit powered from a 12V lead acid battery battery with long leads so am expecting LC spikes that ...
- 219
0
votes
0
answers
24
views
Protection of my loads (batteries + equipment) from alternator
I have an aftermarket additional alternator (24v, 100A) installed in vehicle without external regulator (don't know about internal regulator). I have found this alternator locally probably used ...
- 1
0
votes
0
answers
34
views
Variable Resistance in LTspice- Convergence problems + understanding the solver
I've created a variable resitance model in LTspice to simulate the behavior of a Metal Oxide Varistor. The variable resistance is performed with a behavioral source aas follows:
...
- 97
1
vote
0
answers
49
views
Can this circuit limit power surges?
This circuit I had created based on MOV and a relay, it principle is: if a surge comes the MOV would get activated and should turn the relay thus the surge should be redirected.
Notes:
Input is ...
0
votes
1
answer
30
views
Surge Protection for MIL STD 704A
I have to protect a switching DCDC converter for MIL STD 704A standard especially overvoltage 70V 20ms and 80V 50ms. TVS diodes does not protect because they protect for voltages <1ms. Do you have ...
1
vote
1
answer
65
views
Why clamping voltage is not given for some ESD diodes
I was comaparing two ESD diodes.Their P/N's are PESD5V0S1BL,315 and
PESD5V0U1BL,315.
If you check the datasheet of both parts you can see that clamping voltage is specified for PESD5V0S1BL,315 and ...
- 1,580
2
votes
4
answers
200
views
Multimeter blown trying to measure 125 V in the 600 V AC range
I used a multimeter in its 600 V AC range to measure the voltage across a socket of a surge protector that is rated 125 V - 5A.
As soon as I inserted the test leads, there was a pop and a bright flash....
0
votes
2
answers
84
views
Trace width calculation for surge current
How can I size my current carrying trace width for surge current? any standard or formula?
0
votes
0
answers
41
views
Common neutral vs common earth in surge protection devices
I came across two different connectivity options for SPDs:
Option - 1: Common earth
Option - 2: Common neutral
Both of these types come from the same company. My observation is that most of the SPDs ...
- 7,946
0
votes
2
answers
64
views
Lightning arrestor for a building with VHF antenna without disrupting wireless signals
Lightning protection is to be provided for a building where already VHF antenna is available. An omnidirectional ground plane antenna is used for VHF. The height of the Franklin rod provided as Class ...
- 101
1
vote
1
answer
133
views
Does car alternator speed increase during load dump?
I am trying to understand the mechanism of voltage surges during load dump in automobiles.
As per this article -
The load-dump event has two components. First is the pulse amplitude (VP), which ...
- 2,621
0
votes
0
answers
56
views
Selecting SPD for a Solar panel
If the solar panel (only 1 panel used) max open circuit voltage (Voc) is 38 V
AND
MPPT controller's max input voltage is 49.5 V, what should be the DC SPD (surge protector)'s maximum continuous ...
- 51
0
votes
1
answer
36
views
How can I regulate voltage with multiple AC motors?
I have a water treatment system that has several motors and pumps from blowers for aeration to submersible 3hp water pumps. A lot of these motors have to be repaired and replaced often, sometimes 2 ...
- 207
0
votes
1
answer
48
views
Voltage protection level Up of SPD (surge protection device)
I was going through the datasheet of the below SPD.
https://www.phoenixcontact.com/en-pc/products/type2-surge-arrester-val-sec-t2-3c-350-fm-2905339
It says, Voltage protection level Up ≤ 1.5 kV
It ...
- 1
1
vote
1
answer
47
views
Question about EMR coil surge suppression
I was thinking more about the circuit in Will a FDP3682 MOSFET work in this delay circuit?.
In my current design, I have a TVS (SA18CA, Vc ≈ 30V) across the relay coils. However, I also have a bunch ...
- 481
0
votes
1
answer
110
views
How to protect a relay from power surge?
simulate this circuit – Schematic created using CircuitLab
I am trying to control an LED bulb using a solid-state relay, the problem is, the bulb is flickering from time to time, if it is turned ...
1
vote
1
answer
99
views
Is it legally allowed to install lightning rods in rainy or cloudy weather?
I had a look at some standards (such as IEC 62305 & IEC 62561 Standards for Lightning Protection) on how lightning rods should be constructed, and also searched the internet. I found no real ...
- 11
0
votes
0
answers
50
views
Non-isolated DC/DC converter safety question
If I were to have a 350VDC or similar bus voltage, protected by solid state switches meaning near instantaenous shut-down, what would the safety implications be if I were to use to step down this ...
- 305
2
votes
2
answers
480
views
Difference between Surge, ESD and EFT
I was going through this ESD Presentation where I noticed the below image:
I'm trying to understand the different types of overvoltage and they have given the classification above.
In this, what I ...
user220456
0
votes
1
answer
182
views
Surge suppresor design - DM, CM chokes and resistor is series with varistor
While designing a surge suppressor, I came up with an online schematic where they use a differential mode choke and a common mode choke.
I put one toroid choke coil as the differential mode choke.
...
- 466
1
vote
1
answer
114
views
Protecting output line driver against accidental activation of phantom power
This diagram:
shows an output stage that can be used to drive balanced lines. Here, it is used on a piece of audio equipment and connected to an XLR jack.
However, I want to make this "idiot-...
- 225
2
votes
1
answer
331
views
RCCB trips when lightning even after installing a shunt-type surge protector. Does that mean the SPD was not installed correctly?
I have installed a shunt-type surge protector (SPD) after the main switch, but before the RCCB. A separate earth wire (with separate grounding) was used for the SPD.
Sometimes during heavy (indirect) ...
- 51
0
votes
1
answer
109
views
Difference between D, D+Z and TVS for inductor surge suppression
Let's say I have a switched inductive load (e.g. a lift/hold electromagnet, electromagnetic actuator, or relay coil). IIUC, when the switch/EMR/SSR opens, the collapsing magnetic field can cause the ...
- 481
2
votes
1
answer
93
views
Using common mode inductance or differential mode inductance in a power circuit?
The question derives from my last question.
When the power circuit is powered up, there is surge because of the input capacitor. The surge is a differential mode signal. So to reduce the surge, why ...
- 477
0
votes
1
answer
35
views
Need some help on this surge protection circuit
I found a surge protection circuit.
If we don't take any measure, there will be a huge surge caused by the charge of C4. So I think the working principle is like this: C6 is gradually charged until ...
- 477
0
votes
2
answers
97
views
Is lightning waveform a special case of RC discharge circuit? Why is it modelled as a double exponential function?
As per wiki: The electric current within a typical negative CG lightning discharge rises very quickly to its peak value in 1–10 microseconds, then decays more slowly over 50–200 microseconds.
Why ...
- 2,621
0
votes
0
answers
47
views
Surge protector + mains power adapter safe?
I was looking for a surge protected power strip/extension lead that could be mounted, have 6 or more outlets and came with a 5 meter mains cable with Type G (British plug) inlets and outlets. Having ...
1
vote
6
answers
387
views
Why does a diode placed in series before an inductor not protect from surge?
I checked some posts that explain quite well the concept of a freewheeling diode, but all of them seem to place the diode in parallel with the inductor.
Why doesn't placing the diode right before the ...
0
votes
0
answers
31
views
Can electricity distribution transformers increase lightning surge current from 30 kA to 1500 kA?
I read somewhere that an average lightning strike is about 30 kiloamperes and lasts for a duration of 30 microseconds (but it may consist of number of sub-flashes so the total duration may be 0.2 ...
- 1,563
0
votes
2
answers
51
views
Surge current capability of LFP batteries
LFP batteries, like all batteries, have a limited max current output. Unlike the grid, understood as a "giant battery," which can deal with an A/C compressor's demand of up to 2x of its ...
0
votes
1
answer
79
views
Protecting Circuit - ESD
I'd like to know on how to select the transient protection circuit components for my Ethernet Interface.
I saw a reference design that uses a pair of UCLAMP3301D and 2.2Ω series resistors to the jack ...
user220456
1
vote
1
answer
70
views
Spike and surge protection for electronic boards
I'd like to protect from spike, surge, and so on... an electronic interface that is powered from a 220V / 5V DC power module (AZ Delivery AC-05-3).
The board, designed by me, integrate and ESP 32 ...
- 359
0
votes
3
answers
680
views
How to avoid voltage spikes from solenoid valves?
I want to control a solenoid valve (24VDC, ~10W) using an ESP32 MCU. My initial approach to do this was to use a GPIO pin to control a transistor, which again should control a coil relay. This coil ...
- 35
0
votes
3
answers
106
views
Running multiple devices off a single SMPS [closed]
Disclaimer: I am a DIYer/Hobbyist
I have a few 12 V devices, each with their own 'wall-wart'. I would like to keep everything a bit more tidy, by having all of the following devices connected to a ...
- 111
1
vote
1
answer
168
views
Automotive ISO 7637-2 transients and LT4363 surge protector chip
Can this part be used for the +150V / -220V transients in the ISO?
Taking this diagram:
And modifying it to this:
Where the IXFP60N25X3M is a 250V capable N_MOSFET and R_sns = 5 mohm for 10A max.
...
- 1,050
2
votes
2
answers
193
views
How does lightning increase the voltage within a substation (how does current increase voltage)?
I'm new within the power industry and was introduced to a scenario I had a question about. So, while discussing the need for surge arresters came up, we began talking about lightning. I know that ...
- 315
1
vote
1
answer
83
views
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: ...
- 7,946
2
votes
0
answers
72
views
Will use of isolation transformer advise in lightning prone area?
I am working on a Radio Station located on a hill top. There are frequent lightning strikes during the monsoon season and they sometimes damage electrical equipment inspite of providing earthing. I am ...
- 381
6
votes
1
answer
170
views
Addressing poor Earth resistance on hill top
I work in a radio station situated on a hill top. The Earth resistance measured at this location is quite high, measuring around 9 Ω. There is no deep gorge nearby to make a fresh Earth Pit. How can I ...
- 381
0
votes
1
answer
59
views
LTC4380 Surge stopper MOSFET logic
The LTC4380 is a surge stopper that clamps the output voltage to a predetermined value. It also limits the surge current. The MOSFET M1 needs to be selected so that it operates in safe area (SOA).
...
- 171
2
votes
2
answers
406
views
What does this symbol mean in the internal circuitry of a surge protector device?
Can't find anything on what the symbol inside of the red circle. Any identification of the symbol would be appreciated, bonus love for its functionality in this circuit as well!
Link to the datasheet.
- 827
2
votes
0
answers
98
views
EMC surge protection
I have a product being EMC tested. It passed all but the surge test per IEC 61000-4-5. For mitigation, they have suggested the addition of some type of surge protection circuitry like MOVs.
The ...
- 21
3
votes
1
answer
321
views
Help identify schematic symbol
Is it a ferrite bead or coil of some sort?
Or is it a gas discharge tube? Usually though it has a different symbol.
If it is a ferrite bead then what is the point of those chassis connectors?
Could ...
- 171
1
vote
0
answers
110
views
High-voltage resistors versus anti-surge resistors
I am making a voltage divider with four 1M 1206 thick-film resistors and a single 2.7k resistor. The input to this voltage divider will be mains line and neutral.
I want to measure the voltage at line ...
- 241
1
vote
1
answer
78
views
Could ground faults in the same building affect my anti-static grounding plug?
I have some tools for anti-static purposes for repairing a computer: an anti-static wrist strap, an anti-static mat, a grounding plug on which only the earth pin is metal (the hot and neutral are ...
- 67