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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23 views

Active short circuit of motor phases to prevent higher voltages, what actually happens here?

So we have been using this technique called 'Active Short Circuit(ASC)' whenever the battery is disconnected or the inverter is being run from external bodies. So what actually happens in the coil ...
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74 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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Protect my C source code [on hold]

I'm working on a company that produces instruments and transmitters such as temperature transmitter, pressure transmitter, etc... . I have local libraries that I wrote years ago and they are belonged ...
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38 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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102 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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37 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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49 views

Under-voltage lockout or linear regular or just a Zener diode?

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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30 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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19 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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41 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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42 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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72 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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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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Over Curent protection for multiple consumers

While designing a light fixture I came across an issue. The fixture is powered by a single ACDC unit that generates 24V. The fixture has around 50 LED elements that are connected to the power source. ...
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104 views

A device used to logically turn on a circuit with voltage being the input parameter

I’m working on a project which utilizes a power-source which is liable to vary. I have a micro-controller sitting at the output of an LDO (Low Dropout Regulator). I’m concerned about the LDO ...
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106 views

Polyfuse with Crowbar for Over Voltage

I am looking to add overvoltage protection to a circuit of mine. A standard way of doing this is with a crowbar circuit with a fuse to blow when tripped, thus disconnecting the circuit. However, I ...
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14 views

ITS4060S-SJ-N overvoltage protection

I (think I) want to use an ITS4060S-SJ-N (+datasheet) in a circuit that can't handle over 40V (an LM2576T-5), but will normally receive 8-30V with a ≤12W load. Its purpose would be to provide ...
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Protecting back to back mosfets

I'm designing a high side back to back common source bidirectinal power switch made from n-mosfets. schema: Schematic attached. The questions: How can i protect driver from voltage spike from ...
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31 views

Dual N-channel mosfet Rdson value

I'm going though datasheets of some dual N-channel MOSFETs for li-ion battery protection, like 8205A or ECH8695R, for some thermal and power dissipation calculations. There are Rds(on) values, like ...
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175 views

What is the purpose of this 5 V protection circuit?

I'm working in the OEM company and I want to know what the purpose of the below circuit is. Whether +VCC5V0 or -VCC5V0, Q8 is off so I don't know the purpose of this circuit. It should be a ...
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95 views

Protected 18650 batteries shut down after I introduce a capacitor to the circuit, why?

I have a 24V audio amplifier that is powered by 8 packs of 6x protected 18650 batteries connected in series to produce 24V, and then all the packs are connected in parallel. The amplifier powers a ...
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52 views

Inrush Current effect on a Relay

I am confused about inrush current for a relay. For example, if I had 12A as the inrush current due to a motor, if the contact rating of a relay is only 6A, does a new relay need to be chosen? As in ...
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87 views

Need help understanding DALI circuit and 220 VAC protection

I am making a circuit to interface my MCU with a DALI bus. My basic circuit works and I am able to communicate on DALI bus. It looks like this: I fully understand the above circuit. After my base ...
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39 views

ADC Measurement on Automotive Circuit with Arm MCU

I'm trying to develop a circuit capable of measuring voltage on 6 different automotive pins at 12V nominal. I'm hoping to use the integrated SAADC in the nRF52832. I've done some research into ...
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58 views

Identification of a protection IC

I need to find a replacement part for a burnt IC. It is placed between a MCU and some exposed IO. It was burned by applying 12V as input when 3V3 was the absolute maximum rating in the datasheet of ...
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209 views

How to prevent someone clone PIC [closed]

ACT 1 Okay I know there is code protection system on PIC. But it is preventing someone read the code, not copy. It looks still easy to clone and run on another circuit. Can you suggest another ...
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57 views

replacing a lithium ion battery protection circuit

I read several other postings regarding BMS's but as this is my first attempt to use them and I guess it can be a fire hazard choosing the wrong part, I'm going to ask: I have a battery-powered LED ...
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24 views

Reverse polarity protection LiFePo4

I'm doing a project with esp32 devkit v4 and I'll be supplying it with external power (LiFePo4 3.2V cell). I want to do a protection in case the battery gets connected inversely. I searched about it ...
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67 views

Circuit diagram question - microcontroller input protection

I'm new to electronics, and I would like someone with more experience to look at my diagram. The circuit consists of: a 5 V regulator (from a 12 V input) that powers the microcontroller a pull-up ...
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71 views

P-Channel MOSFET reverse polarity protection on NMOS array chip

I'm trying to achieve reverse polarity protection for the TPL7404LADR chip which is basically an updated version of the ULN2003 darling transistor array. To do this I want to use a P Channel MOSFET ...
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171 views

Disadvantage of using a Schottky diode across the LDO input/output for reverse voltage protection

I'm studying a linear power supply circuit design for my future project and I started off disassemblying a good(expensive) LPS out in the market. While I was studying it, there was a part that I wasn'...
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93 views

how to make an ESD sensitive circuit?

I have an experiment where I plug a sensor to an ESD (Electrostatic Discharge) protection circuit. Sensors are very expensive and very sensitive to ESD. I have tested my protection circuit it is ...
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1answer
58 views

Protecting RS-232 from overvoltages

I am using Some arduinos (5V Pro-Mini, but planing to move to actual ATMEGA chip) over a distance of few metres. These are connected using standard Alarm cable (I had problems with Ethernet cable and ...
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61 views

Smart undervoltage protection

what is the simplest way to regulate the min DC voltage in a circuit? ...
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230 views

Pre-amplifier input protection

I am building the Velleman K1803 pre-amplifier kit. This amplifier has a maximum input signal of 40mv. The audio input to the pre-amplifier will be a piezo-electric sensor, and this can certainly ...
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23 views

Motor-side of BLAC supply goes into overvoltage when regenrative braking using an LM5060

I am currently using an LM5060 for protection of the motor supply on my BLAC motor driver. Everything works well until I decelerate the motor quickly, this makes the supply voltage peak above the OVP ...
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40 views

Protective-Earthing the chassis with the earthing point being the star-point - How does it keep the Chassis at Earth potential?

I always understood that one of the two purposes of protective earthing is keeping the electric potential difference between the chassis of a devide and the ground (the ground I am standing uppon ...
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56 views

150 A 12 - 16 V DC Short Circuit Protection

I am powering a ROV from a 4S LiPo battery (12.0 V minimum, 16.8 V maximum). The resistance of the battery is 36 mΩ, so that a maximum current of 470 A can flow through a short-circuit. In order to ...
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63 views

voltage transient protection for MV Motors

What types of transient voltage protection is applied on medium voltage motors and are these types of protection that are applied depended on the type of motor it is e.g Synchronous vs Induction motor?...
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76 views

How does this isolation transformer protect user from transients/mains?

I'm looking at a pretty simple overvoltage/transient protection circuit designed to protect users but I don't understand what the transformer is doing. The circuit is designed to protect the output ...
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70 views

Device for preventing 12V battery from dying

I am looking for a device which cuts off the connection between batteries and the system just like a circuit breaker when my 12V battery goes below 9V(for example) for preventing it from dying ...
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2answers
39 views

How to check protection circuit in lithium battery

I've recently bought a single cell, 600 mAh lithium battery (like this one) and a TP4056 battery charger module, which I intended to use with the battery. The charger has an integrated protection ...
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1answer
45 views

Protection for transistor driving a coil

I recently purchased a few electromagnets. I want to drive these with transistors, but I want to build in protection, as these don't have any available specs re: max operating temp, duty cycle, etc. (...
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52 views

RTD circuit in industerial application

I'm trying to design RTD measuring for industrial use which has EMI/EMC/ESD. I have 3 wires input to the board. obviously 3 wires out of the board are going to 3-wire configuration PT1000 1- 3V3 (...
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68 views

±12V protection for MIDI input

TLDR; how to make a MIDI input withstand shorting to \$\pm12V\$? This is a counterpart to this question, I'm asking this as I was inspired by the great answer I got there. I'm designing a MIDI input ...
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140 views

±12V protection for MIDI output

TLDR; how to make a MIDI output withstand shorting it to \$\pm12\$V? I'm designing a MIDI output in a eurorack modular synth module on a TRS jack (this is a semi-standard non-standard way to save ...
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108 views

MCP73871 Battery Under Voltage Protection

I want to use MCP73871. Is there a battery under voltage protection in this charger IC? or may I use a battery protection IC? Answer for @Bimpelrekkie I decide to use my power architecture as ...
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138 views

Cause of high failure rate in SC189 buck regulator

I have a small board that uses the SC189C buck regulator to take 5 V down to 3.3 V. For whatever reason somewhere between 25% and 50% of these boards have had the voltage regulator fail at some point, ...
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69 views

What is the difference between these two protection circuits?

I have seen both protection circuits used in various designs. The first just back to back diodes clamping a line, the other clamping the line to the system voltage rails. Whats the difference between ...
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184 views

Mosfet Gate-Source Zener [closed]

I want to confirm this circuit is going to work and ask how to calculate the zener voltage. The load is going to be driven by 30 volts, and the gate voltage is the same 30v, through an optocoupler.