Skip to main content

Questions tagged [surge-protection]

Questions about protecting electrical devices from voltage spikes.

Filter by
Sorted by
Tagged with
0 votes
0 answers
50 views

Explination for arcing noise coming from protected power tap devices?

For years now there has been a random occurrence that happens with seemingly any power tap device I have with protection circuitry in it where it will make a audible buzzing/arcing sound for a few ...
Jacob Jewett's user avatar
-1 votes
1 answer
71 views

Voltage and current on two identical TVS diodes in parallel during a voltage spike

Suppose I have two identical unidirectional TVS diodes (A and B) connected in parallel to a voltage source and suddenly a voltage spike occurs (spike voltage > voltage clamp of the TVS diode specs ...
marcosbc's user avatar
  • 450
5 votes
1 answer
216 views

Metal chassis grounding with wall wart supply, ESD test failed

We're building a device which takes its input power from a 12VDC wall wart PSU, and has a metal chassis. We just passed preliminary EMC/EMI test, but in the ESD test an 8kV jolt to the chassis killed ...
Timo's user avatar
  • 1,259
0 votes
1 answer
26 views

Does the unidirection TVS diode like SMAJ15A be used on DC lines to protect the IC or Converters from negative Peak, clamp down to -0.6V?

Most of the DC- DC converters have absolute maximum down to -0.6. If bidirectional TVS diode is used then negative peak cannot be clamped near to -0.6v, in this is the case can we use the ...
Raviteja Cherukuri's user avatar
1 vote
1 answer
40 views

Problem: Transient Voltages in Grounding Circuit Cause comms loss

I am working with a Hipot unit to break down a DUT. The Hipot is powered by an independent 220V Ckt. In my test setup I have a PC and another unit, both of these are powered from separate 120V ...
Juan Antonio's user avatar
0 votes
2 answers
76 views

Zener MOSFET Voltage Limiter

I need an input protection for a DC-DC converter in a 24V automotive system environment. The DC-DC is capable to accept 50V input but I need some sort of protection against load dump pulses which can ...
Emanuel's user avatar
1 vote
1 answer
61 views

Input protection close to maximum voltage

I'm planning a CAN network based on the CANbed RP2040 where the boards will be connected via fairly long cables (1 to 5 metres) to a LiFePo4 battery as shown below: simulate this circuit – ...
DamienWontContributeToAITheft's user avatar
0 votes
1 answer
38 views

Using MOV to protect device for heater element

I have a heater element that is controlled by a solid state relay from main power. I know it is customary to place a MOV in parallel when switching inductive loads to clamp the voltage to prevent ...
realm god's user avatar
1 vote
1 answer
53 views

Identify part "S8851": apparently input protection

Could someone identify help identify these please? I think they're some kind of input protection: they are open-circuit, each from a pin of an RS-422 connector to chassis. Labelled "S8851 / 1....
jonathanjo's user avatar
0 votes
0 answers
47 views

What are the meaning of the simple directional arrow above the double arrows in this schematic?

Helo,, I would like to know what are the simple directional arrows above the double arrows in this schematic?.
Daniel Prieto López's user avatar
1 vote
0 answers
36 views

Handling higher clamping voltage of IsoMOV - MOV/GDT Hybrid

I'm working on an ac mains control circuit and came across IsoMOV a new hybrid MOV/GDT for surge suppression. This appears to be a straightforward replacement for a standard TPMOV with additional ...
fivejeez's user avatar
  • 123
0 votes
1 answer
44 views

Protecting Triac + Relay from surges

I am having 3 triacs and 3 relays that are used to control heater elements in triangle configuration. Atleast the triacs need some kind of surge protection since they can only handle 800V and surges/...
vawp's user avatar
  • 45
2 votes
1 answer
56 views

Managing Ground Return for High Surge Currents in LED Capacitor Discharge Circuit

I have a use-case in which I require four bulk capacitors (470uF) charged to 6.4V. Each separate bulk capacitor will be used to provide the necessary energy to pulse a string of three LEDs at 5μs ...
NickRand's user avatar
1 vote
4 answers
129 views

Risks of placing Varistor before Fuse for Mains Voltage

I have seen many questions on this and other forums asking about the best option to place the fuse relative to the varistor to protect it from mains voltage spikes and the answer was unanimous: The ...
Dinis's user avatar
  • 73
0 votes
1 answer
159 views

MCU Input ESD Protection + debounce

I'm working on a device which requires reading from a reed switch (slow, water meter) which should work in a bit noisy environment (a few relays switching back/forth on the same board, triacs and ...
Taras Shcherban's user avatar
0 votes
2 answers
104 views

Surge Voltage Protection

I am currently working on designing a protection circuit for mains power. However, as a hobbyist rather than an expert, I am seeking assistance with this circuit. During my research, I came across an ...
M-125's user avatar
  • 53
0 votes
0 answers
26 views

Choosing SPD for Solar Panel & Inverter

I have 18 Solar Panels Installed in series (Maximum open circuit voltage)VOC is 51.8 V & Operating Current Imp 13.36 A AND MPPT Inverter Max PV Voltage 1100 d.c. V MPPT Voltage Range 140 ...
RKhan's user avatar
  • 1
5 votes
2 answers
299 views

Should I and if yes, how should I be protecting this linear power supply for IEC 61000-4-5 surge testing?

I have a product currently in the EMC testlab going through EN 55032 and EN 55035 (audio hardware) waiting to do the final tests on 61000-4-5 surge immunity. Up to this point, all tests have been ...
zloopy's user avatar
  • 51
1 vote
1 answer
174 views

Does a 48 VDC system need to be grounded for lightning protection?

TL;DR If you wish to use DC surge protection products such as these (datasheet), do you need to bond the DC supply to ground? When they trigger, where does the excess current in a surge actually go? ...
Malvineous's user avatar
  • 1,795
13 votes
4 answers
4k views

Is a 100 Ω/1 nF RC low-pass filter enough to protect a microcontroller I/O pin from ESD?

While researching ESD protection on this site, I came across this question. The answer by Peter Smith contains a comment by @Ale..chenski: Just a nit pick: if you can afford 100R and 1nF to ground on ...
Unimportant's user avatar
  • 4,683
2 votes
1 answer
143 views

ESD protection when reverse stand-off voltage and required clamping voltage are close together

The circuit under consideration is to be powered by four 18650 li-ion cells in series. These cells are in a holder and user replaceable so there is risk of the contacts being touched and adding esd ...
Unimportant's user avatar
  • 4,683
0 votes
0 answers
109 views

Snubber circuit with MOV for relays connected in series

I have 5 identical relays (same specifications) whose working input voltage is 24V DC and output voltage is 220V AC. I have a problem that voltage spike due to large capacitance when switch turns on, ...
Choi Moonkee's user avatar
1 vote
1 answer
52 views

Using two varistors in series when there is no possibilty of using single component

I need to use Varistor to protect the circuitry from 6kV 1,2/50us impulse. Varistor has to be between input + and - wires. The operational voltage between this two input pins can be up to 1050 V. I ...
Kurt Müller's user avatar
1 vote
0 answers
327 views

Optimal Protection Circuit Configuration for TMC2209 Stepper Motor Outputs

I am currently working on a project involving a stepper motor driven by a TMC2209 driver. I aim to implement effective protection for the motor driver outputs. According to section 3.7 of the TMC2209 ...
Murtuza Quaizar's user avatar
2 votes
1 answer
109 views

TVS Diode Transient Response to Surge and Current

I want to simulate the transient voltage response of a TVS Diode against a surge using an exponential voltage source with this characteristics: Initial value 0V Pulsed value 100V Rise delay time 0s ...
marcosbc's user avatar
  • 450
3 votes
1 answer
127 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://...
user avatar
1 vote
1 answer
126 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 (...
user avatar
2 votes
1 answer
394 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 ...
user14665305's user avatar
0 votes
2 answers
106 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? ...
JoeyB's user avatar
  • 2,391
4 votes
3 answers
917 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 ...
David's user avatar
  • 4,570
0 votes
0 answers
158 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 ...
codebrane's user avatar
  • 219
1 vote
0 answers
56 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 ...
Hazardous Voltage's user avatar
0 votes
1 answer
149 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 ...
Emre Demirtaş's user avatar
1 vote
1 answer
72 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 ...
Confused's user avatar
  • 2,593
2 votes
4 answers
297 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....
Dat_Derpy_Dude81's user avatar
0 votes
2 answers
203 views

Trace width calculation for surge current

How can I size my current carrying trace width for surge current? any standard or formula?
Arun Kumar Thawait's user avatar
0 votes
2 answers
116 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 ...
RoyOneMillion's user avatar
1 vote
1 answer
179 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 ...
Dynamic_equilibrium's user avatar
0 votes
0 answers
138 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 ...
asan123K's user avatar
0 votes
1 answer
39 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 ...
DAB's user avatar
  • 207
0 votes
1 answer
161 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 ...
Gopal's user avatar
  • 1
1 vote
1 answer
88 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 ...
Matthew's user avatar
  • 572
0 votes
1 answer
211 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 ...
Ahmed_4EGA's user avatar
1 vote
1 answer
119 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 ...
onuryildiz's user avatar
0 votes
0 answers
75 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 ...
Brandon Kellett's user avatar
3 votes
2 answers
1k 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 ...
user avatar
0 votes
1 answer
586 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. ...
15 Volts's user avatar
  • 707
1 vote
1 answer
281 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-...
user avatar
2 votes
1 answer
882 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) ...
asan123K's user avatar
0 votes
1 answer
278 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 ...
Matthew's user avatar
  • 572

1
2 3 4 5
8