Questions tagged [protection]

Ancillary circuitry added to a design that provides protection of the main circuitry to enable the main circuits continuing functioning. In some cases the protection circuitry is sacrificial, being destroyed or degraded in the act of protecting. But not all protection circuits may do this. Examples of faults protected against are: Overvoltage, ESD, overheating, Overloading (too high of a current draw) amongst others.

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33 views

Connecting two RCD's serially

I want to make a electric leakage protection circuit for a water heater in case of heater gets corrupted in time. We use rezistance 220V - 1500 watt. We grounded the water (because rezistance have ...
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70 views

GaN FET short-circuit protection

From Texas Instruments snoaa15, which is an Application Report about overcurrent protection of GaN FETs, in the first page, you can read the following quote: Traditional approaches using current ...
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1answer
47 views

Back-up battery

for a project I would like to design a system which would allow me to feed my application's logic rail from a back-up battery if the main battery would somehow stop functionioning (most likely due to ...
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1answer
39 views

load balancing in supercaps

Our circuit has three supercaps in series across the Battery+ and GND rails. The average current draw is very small -- around 250uA -- with peaks of 20 mA. Short form Do we need load balancing ...
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67 views

24V Isolated digital input protection TVS

I am working on creating 24V industrial Grade(Like Siemens PLC I/O) Digital Input circuit,The micro will use the 3.3V supply. circuit works with TWO input signal one of them is 24V industrial "24V_sig"...
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68 views

How does this flame ionization detector circuit work?

I'm working on a flame ionization detector (FID) which can read the ionized flame signal by micro controller ADC. According to the following schematic, what is the cause of exciting 220 V phase and ...
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54 views

PTC or One time Fuse or fusible resistor for li-ion protection.any suggestion?

I designing a kind of portable device ,it contains 450mAh Li_ion or Li_Poly Battery (depends on space on PCB). I design this system for mass production (10k-20K). I want to add overcurrent protection ...
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77 views

overvoltage and transient protection for ADC pin

I'm building an industrial circuit, and want to use 0-10V and 4-20mA sensors in this circuit. I want to protect my ESP32 MCU(NodeMcu board) from transients and high voltages. I design this circuit and ...
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2answers
50 views

Resistor ratings for inductor fly-back suppression

I am building a circuit for user to interface with relays, and I am trying to build a protection to the circuit against fly-back from the inductor coil of the relay. Since there is no specific relay ...
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2answers
48 views

BLDC/BLAC controller motor voltage reverse protection

I am currently designing a BLDC controller and keep running into a power safety issue: I have added a smart diode reverse protection controller to my design with its transistor between the fuse and ...
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1answer
49 views

Poly fusing external peripheral device

The design I am working on is having peripheral connector with +5V power in it providing the voltage to the would-be connected device. There's relatively a long way inside the design from the ATX ...
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3answers
107 views

How to suppress a short circuit to prevent fuses from blowing [duplicate]

I have a circuit that is modular and one of the modules involves interfacing from an external relay. Now this sub-module has a fuse set to blow a bit below what the main module's max current. (why ...
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39 views

How to prevent reverse current/voltage on a sense line?

I'm designing a rocket launch controller, that incorporates an Arduino to provide a safer and more controlled launch. Original rocket launch controllers used to use an incandescent light bulb and a ...
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1answer
78 views

Is this a reasonable setup for terminating and protecting an RS-485 transciever?

I'm working on a design where an RS-485 transceiver IC is connected to a Cat5e cable, hopefully at 96k baud at a distance of up to 150m. I'd like to offer some protection in the design, but I've never ...
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2answers
30 views

DW01 LiPo Protection not auto detecting

I've designed a LiPo charge/protect/boost circuit but am having problems with the DW01 protection IC. The IC successfully cuts off the battery when the voltage goes below 2.4V, but it doesn't auto-...
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1answer
73 views

Is this circuit for driving a piezo buzzer correct?

I'm designing a board which will feature a small SMD piezo buzzer which will be used for generating tones of varying frequencies from a PWM signal. I'm looking for a simple circuit which will be safe ...
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18 views

Using a TP4056 with a 08570 Battery

Will a TP4056 (the ones with mini USB and no battery protection) charge a 08570 battery safely? From what I can tell the battery does have built in battery protection but I cannot find much ...
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127 views

Is there a simple short circuit protection available?

One of my little copy/paste projects died again (a 12V 1 A circuit - last time it died). Now it was a short that caused it. Is there a simple way of keeping my parts from burning? By simple I mean ...
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3answers
113 views

Any importance to TVS 'parallel' vs 'series' Topology?

I am working with an existing schematic which has bidirectional TVS surge protection, laid out like this: simulate this circuit – Schematic created using CircuitLab The TVS diodes are ...
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1answer
147 views

Opamp output short circuit protection

I am trying to build a voltage generator 0-10V to feed the input of a PLC ADC card (for simulation purposes). The PLC card has an input impedance of 133k. I am thinking to use the circuit from the ...
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1answer
73 views

Deep explanation on TVS diode voltage suppression?

I am looking for a deep explanation on why a TVS diode suppresses voltage. All of the research I have done on Google just says 'it suppresses voltage by shunting current', but this doesn't make sense ...
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1answer
105 views

ESD SPI/ISP bus protection

I am designing a board based on the Atmega328P microcontroller. For this controller there is an ISP connector for programming. This connector has the following pins: MOSI / MISO / RST / SCK. There is ...
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33 views

ESD Input protection on low Vmax digital inputs (3.6v)

I have a microcontroller monitoring a few digital inputs. The max voltage on these inputs is VCC + 0.3v. VCC is 3.6v so these inputs can't be higher than 3.9v. These digital input are just switch ...
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38 views

Will the BQ2970xx IC do everything I need for Li+ battery protection?

I'm modifying a circuit to use a rechargeable 1S LIR2032 coin cell battery. This is my first time using Li+ and understand I need to add circuitry to protect the battery/circuit. My specs are: Max ...
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34 views

pulled down io protection from overvoltage

I need to protect my IC's io form overvoltage(default is 5v). The pin has the capability to source 10 mA and sink 25mA I tought of using a tvs diode(between pin and gnd) and a resistor(330r from pin ...
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3answers
55 views

Input Protection Diodes Functioning with Circuit Breaker?

I was wondering if I was correct in assuming these diodes were being used for ESD protection on the input of a power circuit. I'm a little bit confused what the point of the diodes are when there's a ...
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48 views

Protecting IC from voltage spikes

I'm currently designing a PCB with a boosted audio amplifier. It is powered with a single li-ion cell with 3000mAh capacity. According to the datasheet of the audio amplifier, it is recommended to add ...
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0answers
65 views

Buck converter shutdown

I just put together a buck bonverter PCB that I designed and am using the SiC437 from Vishay. DataSheet I am using a power supply to control and measure the input supply voltage and current. I am ...
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1answer
35 views

Protection circuitry for AC/DC converter

I'm using the RAC02-GB (Datasheet) as an AC/DC converter and I'm confused about the protection circuit they included in the datasheet: I want to make sure the AC/DC converter has the proper external ...
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1answer
65 views

How to draw ~1A from Li batteries without damaging/over-stressing them?

I have designed a micropump driver powered by 2x AA (Li) batteries, the pump is piezoelectric and requires 27V. The pump requires a switching waveform, at the battery side this draws (including ...
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62 views

Reverse Voltage Protection with feedback circuit

I would like to understand on the feedback transistor circuit in the given reverse voltage protection circuit. Voltage Input: 7V to 32V.
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1answer
59 views

LiPo Shrinkwrapped components

Besides over voltage protection, what other purposes are served by the shrink-wrapped (in yellow) components seen here? Do they have any effect on discharge, and will they discharge the battery other ...
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1answer
76 views

High Speed Input Protection (High Impedance, 12 V Tolerant, ESD-Safe)

I am struggling with an input protection design for my FX2LP logic analyzer (3.3 V microcontroller with 5 V tolerant pins). I wanted to achieve the following constraints for the 8 input pins of the ...
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1answer
89 views

Capacitive load - Circuit protection

I have a circuit which drives capacitve loads (they vary from around 800pf to 1600pf) and because of circumanstances like air polution and dust it can come to electrical contact to the surroundings or ...
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64 views

Arcing contacts corrupt communication. What to do?

I have a robot with external charging contacts and a docking station with exposed pads this robot has to drive into to start charging. When trying to dock and charge I seem to get a lot GND bounce, ...
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2answers
76 views

Power Off and Capacitor Discharge

Could someone tell me where this diode (highlighted part) would be added and the orientation? https://www.maximintegrated.com/en/app-notes/index.mvp/id/287
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30 views

Switch gear & protection - Problem

I'm a B.tech student currently in my 4th year. I was learning Switch gear and protection and suddenly I came across a numerical problem while trying to solve it, I'm having a small doubt as: Is ...
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2answers
83 views

How to use gold finishing to reduce corrosion on a moisture sensor?

Background I have a raspberry pi with a moisture sensor that suffers from corrosion. My setup is similar to the one described in this raspberrypi.stackexchange question about corrosion of a moisture ...
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1answer
144 views

Protect my C source code [closed]

I want to give somebody a project, but i used my own libraries on that and i want to protect my code. I'm currently working with C in STM32 systems. What can i do?
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49 views

Power Distribution Blocks for DC voltage?

So, I'm pretending to use a somewhat uncommon component for my generator system. With an alternator, I will generate 24 V DC and a maximum of 100 A. My question is, can I use a power distribution ...
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1answer
114 views

What's best protection for a really high voltage 50kV generator PCB? [duplicate]

What is the best options for protecting a 50kV high voltage low amp PCB? Encapsulation the components, potting the whole thing or just using conformal coating will be enough for the corona discharge?
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1answer
124 views

AC line surge protection with GDT in series with MOV

We often use GDT in series with MOV to protect AC lines as below. But i have Question as for 230V AC line and 275V Rated MOV - What Should be the Breakdown voltage of GDT ? Three options available :...
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2answers
104 views

How to supply either 5V or 0V without the gradual PSU voltage bleed?

I have a 200W 5VDC power supply (Meanwell LRS 200-5). When I shut off the AC it takes about 60s for the supply to drain fully through the connected sensitive components (processors and storage drives)....
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2answers
32 views

Suitable protection for elements on power line

I am working on mini project with 555 timer. The LED diode is not a diode, but a 12V LED string. What happens if there is a sudden drop in voltage? Motor will induce voltage of opposite polarity. The ...
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24 views

How the directional element in the distance relay blocks the reverse power flow?

Following is the figure for directional element of distance relay. The trip region is also in the second quadrant. How it will restrain from operating if the fault impedance is as indicated by F (in ...
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1answer
47 views

Protection on the AC side vs DC side

The circuit below shows a three phase rectifier with 3 filter inductors at the input side, and a capacitor, a MOV, and fuse at the output side. I wonder what the differences are in protecting the AC ...
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1answer
53 views

Protecting MAX485 data or supply from shorting to 24v DC supply

I have 2000 infrared proximity sensors along 100 meters, divided to 2 meter sections with an arduino reading them sending results by MAX485. For the power, I am supplying same 24v dc from each end of ...
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222 views

How to connect 3 cell series Li ion charger and protection IC for each cell?

I am using max745 4 cell Li-ion battery charger to charge 3 cells in series. I want to put additional protection IC for each cell (NCR18650pf). Because I need to run the max745 always on as a backup ...
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19 views

Protecting a 5.1 amplifier

Some Yamaha models have no protection at all, except a fuse, maybe. I was thinking using a GDT, MOVs plus a line filter in an external box. And maybe adding a 12v latching relay (two pushbuttons: push ...
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4answers
852 views

How to avoid voltage drop when using full bridge rectifier as reverse polarity protection

I found a couple of old bridge rectifiers. After reading some docs and tutorials about reverse polarity protection decided to give them a try. The problem is nobody offered a solution against the ...