Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [over-voltage-protection]

Additional internal or add-on parts to a fixed voltage regulator to prevent the output voltage from exceeding a preset limit if internal voltage regulation fails. Some OVP designs include an SCR to short the output and blow a fuse, rather than risk damage to downstream hardware.

0
votes
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 ...
4
votes
0answers
62 views

Radio module resetting when fluorescent tube switched on/off

I have a PCB powered by an IRM-30-12 power supply (230VAC to 12VDC). On this PCB, I have a MRF24J40MD from Microchip and a Udooneo to drive it + a 5VDC regulator and the 3.3VDC of the Udooneo. After ...
-2
votes
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 ...
0
votes
4answers
67 views

Should I include over-voltage protection for a 3.63V max device using a Lithium-SOCl2 3.65V battery?

When designing an ultra-low-power device that is powered by a primary lithium battery, is it necessary to include over-voltage protection? Specifically, I am using a Microchip (Atmel) SAML21J which ...
3
votes
2answers
461 views

Voltage monitor circuit (reverse polarity protection with high voltage cut-off)

I want to make a circuit which performs these tasks: 1) Protect the load against reverse polarity. 2) Protect the load against over voltage. Load = Raspberry pi Reason for this circuit - Pi is not ...
3
votes
1answer
82 views

How do I size a zener diode for use as a freewheel diode for a ZVS induction heater?

My electronics experience is "hobbyist" and I'm in some new territory with this question, so forgive me if this question turns out to have an easy answer or prove to be dumb. I have a basic ZVS ...
0
votes
1answer
53 views

Why do protective relays have a delay?

6I am a software engineer with a small amount of experience in electrical engineering that has been tasked with designing an embedded OS for a IDMT relay (uni project). However, I don't understand ...
2
votes
2answers
87 views

Protect ADC input from over-voltage with Schottky diodes

Alan Walsh on this article has suggested using Schottky diodes to protect ADC input from over-voltage, the circuit looks like below: simulate this circuit – Schematic created using CircuitLab ...
0
votes
0answers
35 views

Overvoltage Protection for Battery Charger

I'm trying to come up with some form of precise overvoltage protection between battery chargers and batteries between 12V and 48V batteries. I have 12 and 24 sorted using different methods: crowbar ...
0
votes
0answers
52 views

Overvoltage protection circuit - Serial zener diodes and op-amp

I need to prevent people from plugging in batteries with incorrect voltage. The 2 cell LiPo with voltage range from 6.4 to 9.8 V is alright, EN=1. But 3 cell LiPo is too much and I need the below ...
0
votes
2answers
85 views

Why would this (simple) over voltage protection circuit raise the output voltage?

as a beginner I have recreated this circuit: I found it in this guide, and I was hoping it would work as intended but instead it gave me some weird results. I connected power to the circuit and ...
1
vote
3answers
134 views

Overvoltage protection with zener - How do you get a sharp knee clamp for analog input?

I'm working with an MCU that sees a 0-5V input range. I have a possibility where they may accidentally see 12V (user error). My problem is this analog input using a 5V Zener has a knee that isn't as ...
1
vote
0answers
57 views

Smart undervoltage protection

what is the simplest way to regulate the min DC voltage in a circuit? ...
1
vote
2answers
68 views

Understanding STEVAL-ILM001V1 DALI transceiver schematic + adding protections

I'm working on implementing a DALI bus interface circuit. DALI has a few specifics that make this tricky: The device should draw at most 2mA when receiving, it transmits by shorting the bus (250mA is ...
0
votes
1answer
58 views

Over voltage protection for a buck controller 24V in. 4-5V out

Please see Image below, if the output votlage here is 4-5V with current out 3A-15A(depending on LOAD). Could I stick a Zener diode to clamp any over voltages to protect the load from over voltages? ...
0
votes
1answer
57 views

USB Overvoltage and ESD protection

lets say, i am using a LTC4361 ic to protect an usb device from overvoltage and -current. Top Left is GND, below is VBUS, +5V is protected output. How would i deal with ESD protection for the 5V line?...
1
vote
1answer
50 views

Will my zener diode work again with a polyfuse after a overvoltage?

I am trying to make a simple overvoltage & current limiting circuit for my PCB. I made the following circuit. The zener will break down and conduct current to ground. Since its resistance has ...
2
votes
1answer
67 views

overvoltage protection of opamps

simulate this circuit – Schematic created using CircuitLab I see diodes arranged like D1 and D2 sometimes used to prevent nuisance tripping of a power supply's internal overvoltage protection ...
1
vote
3answers
77 views

Over-voltage protection system for a 7 - 20 A Load with 4 - 5.5 V output from PSU

The power supply used on the product, is a DC-DC buck controller 24 V in (3 - 5.5 V out). I need some suggestions to help protect a load (LED Display) which draws roughly 5 - 15 A the power supply on ...
2
votes
2answers
69 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. ...
0
votes
2answers
97 views

Voltage regulator and loss of ground

I have a design that has a +24VDC supply, a 7805 voltage regulator converting it to 5 volts and then a microcontroller and some peripherals behind the regulator. The design and the 24V supply ...
0
votes
1answer
52 views

Digital voltage stabilizer relay diagram

I am using this voltage stabilizer relay diagram below, which provides a 16 step-up level. I need to edit it, so that I can made it to work as step-down in case of high voltages such as 245 and above. ...
0
votes
0answers
109 views

How to shutdown SG3525 inverter with op amp

I'm trying to make an overload protection and low battery indication circuit for my 50 watt inverter. I have made an overload protection circuit using op-amp, but when an overload event occurs the ...
0
votes
1answer
68 views

Input protection on a DC jack

I am designing an battery powered instrument with around 20-40Ah 3S li-ion batteries in it along with a 10A 3S(12.6v) external charger. Due to ease of availability and the current capacity I have ...
0
votes
0answers
35 views

Over voltage and under voltage with time delay device

I made a circuit as shown in the attached picture. It is an " over voltage and under voltage protection device with delay time" it worked properly at the first, but later it stopped giving any output. ...
0
votes
0answers
45 views

DMX protection circuit (diode clipper)

TL;DR I’m building a board that bridges the common types of DMX connector (various forms of XLR, RJ45, tails and product-specific terminals). There is a possibility that someone could accidentally ...
0
votes
0answers
18 views

Voltage applying to cpld I/O pin while VCCio isn't connected

I have a pcb based around a coolrunner II cpld . My problem is as follows. An other ic generated at it's output a logic '1' (around 3.5V ) and the signal was driven to an input pin of the cpld while ...
1
vote
1answer
47 views

LED current source circuit design concerns

TL;DR: Read the bulleted list below. I am designing a simple constant current source to power up some LEDs inside arcade buttons. My project consists of 20 of these buttons. Every button is ...
0
votes
1answer
111 views

Crowbar Circuit for 35V OVP - What parts should I use?

Please excuse my confusion, because I really don't understand what the "150mA max continuous cathode current" means on the datasheet for the LM431. I'm also not sure it'll work in the crowbar circuit ...
0
votes
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 ...
1
vote
0answers
43 views

Techniques for accurate 5.5 Vdc active voltage clamp

We are currently using TI ISOW7841 Digital Isolation modules /w built-in isolated 5 Vdc DC-DC converter Datasheet. We are having rare failures. Failure shows up as the module running much hotter ...
0
votes
1answer
64 views

SMPS Over Voltage Protection

I have some related questions here and I hope I get better understanding thru this forum. ATX SMPS has Over Voltage Protection. Does it mean that it will shut itself down in over voltage situation or ...
0
votes
1answer
60 views

high power - overvoltage protection

I am designing a circuit to protect a load from over-voltage. The voltage at the load must be around 380VDC and the current consumption will be around 2A. In normal operation the Power Supply must ...
1
vote
1answer
52 views

Reverse polarity protection for symmetrical input

I have a symmetrical voltage input I need to protect agains reverse polarity, and over-voltage. Here is the reverse polarity protection I designed. Is it correct ? I can't find much information about ...
2
votes
1answer
66 views

Short-circuit protection, reverse polarity automotive

I am designing a power circuit and would like to integrate the ic VN5160S to protect it, but I have doubts about the position of it. Would the ic VN5160S be before the DC / DC converter in my circuit? ...
1
vote
1answer
28 views

ESD/overvoltage protection with DM1231-02SO TVS array

I'm protecting a USB2.0 IC against ESD and overvoltage at the USB connector using a Diodes Incorporated DM1231-02SO TVS (dual) array. The datasheet labels the pins IN and OUT, but it's not 100% clear ...
0
votes
1answer
77 views

Transistor Reverse Biasing - AC

I am working on a project which require to activate a 24V Rated relay using a 3.3V rated IO. To provide adequate isolation I have added a Opto-isolater stage. In order to increase the current output ...
0
votes
1answer
131 views

Overvoltage protection for AC relay dilemma

I am currently designing a safety-related device that has to open a relay when a certain event occurs. During most of its life, this relay will be closed, and only open if the safety event occurs, ...
0
votes
1answer
201 views

What the function of zener diode on this picture

I am confuse, why we need clamping with zener diode because it doesnt matter when vgs goee below zero, cmiiw
4
votes
2answers
1k views

Long wires causing Raspberry Pi to die?

I've been working on a simple project involving a Raspberry pi and some switches. I would never thought I would have any problem for something as simple as a switch, but here I am. The 2 wires from ...
0
votes
1answer
56 views

Protecting 0..10 Vdc PLC input from voltage divider failures

I'm working on an off-grid PLC based battery bank monitor and dump load controller to replace commercial units that don't work really well with our lithium ion battery bank. In addition, I plan to ...
0
votes
3answers
117 views

How long do I have before my sensitive components get fried?

I'm using this IC (https://www2.mouser.com/datasheet/2/609/ADM1270-878589.pdf) to control the current and the voltage on some of the outputs of a PCB that controls the power to other PCBs, which have ...
1
vote
2answers
342 views

Simple reverse and overvoltage protection circuit for drive a fan

What is the simplest/minimal circuit or component i can use to drive and protect a fan from overvoltage and reverse polarity? A mosfet per fan seens a option for reverse polarity, still if there's a ...
0
votes
1answer
48 views

How can I tell whether a DC device will accept a greater voltage than stated? [closed]

Over the time, as an amateur, I've developed a sense that DC powered devices with internal circuitry should be fed with the voltage stated on the case. Having seen certain devices (e.g a portable USB ...
1
vote
1answer
76 views

Connector pins protection from overvoltage

I have a connector which has the following lines: 12V 3.3V GND SDA (I2C) SCL (I2C) The connector might get wet with water and I would like to protect the circuit from the resulting over-voltage in ...
-1
votes
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
votes
1answer
95 views

Schematic for input protection with NMOS? Does this really work?

I was reading an old schematic and found this and sketched it up; (see box in image "Some kind of protection") The closest thing to this schematic that I've been able to find, that could have briefly ...
1
vote
1answer
49 views

Historical: I am trying to get a handle on when output voltage was used to protect from faulty LEDs

I am interested in when a simple over voltage detector was first used to protect LED arrays from damage caused by one faulty unit. I have a reference from 1999 but am sure I saw something first ...
3
votes
1answer
249 views

Slow-blow fuse equivalent for overvoltage?

Working on an compact electronic ballast design (~5 W load), I see the need for an over-voltage protection circuit that has a 'slow-blow' characteristic. When a lamp is turned on, a striking voltage ...
2
votes
2answers
263 views

3.3V overvoltage limiter circuit topology

I need to design, using discrete components only, a shunt voltage limiter that drains little or no current (less than 2mA, the lower is better) at 3.3V, and ensure that, when driven at more than 4V, ...