Questions tagged [protection]
Ancillary circuitry that protects the main circuitry in case of a fault. Examples of faults protected against are: overvoltage, ESD, overheating, and overloading (too high of a current draw). In some cases the protection circuitry is sacrificial, being destroyed or degraded in the act of protecting.
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Why too many MOVs used in surge protectors?
I got this photo only for reference, and have no idea about the circuit:
but why in this surge protector too many MOVs are used, I mean normally the lowest impedance MOV would take the most surge ...
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Protection still adequate?
I'm trying to protect an analog input (that goes through a MUX and a buffering op amp). Expected input frequency is less than 10 Hz.
I would like to go from the top schema to the bottom one.
LDR/...
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How to protect a motherboard from an old power supply? [closed]
I have an old Taiwanese Senstron ST-41 (TAO YIN-TCY6 94V) power supply from 1987 used in an Apple 2 clone with DC outputs:
5V 5A
12V 2.5A
-5V 0.5A
-12V 0.5A
Is it possible to add extra protection (...
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Does it matter if a fuse is on a positive or negative voltage?
I have a power supply with -5V DC output.
Can I use a fuse 5V 0.5A for this -5V rail as if it was 5V 0.5A?
The rail I want to put a fuse on goes into the motherboard.
The motherboard does not have any ...
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Type of diodes for 9V [closed]
I am looking to protect a 9v battery against a 12v battery.
I know the question has been asked already and someone did put a circuit up as well but I don’t know what type or what model number I need ...
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Jump on varistor I/V curve when "passing" through max. leakage current region to max. clamping voltage region?
I'm taking a course on semiconductor physics and another on something like "usage of electronic devices". On both I've come across the I/V curve on a varistor, this is:
I cannot find the ...
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Modelling a Desaturation detection circuit on LtSPICE
I am trying to model a gate driver desaturation detection mechanism with discrete elements on LTSpice. The waveforms I have obtained now provide a constant Vdesat of about 5.6V when MOSFET is turned ...
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Ensuring Proper Damping and Protection at Power Connector Inlet
I am designing a power input stage for a system (which consumes up to 90W) and want to ensure it is properly damped and protected. Here are the components and considerations I have incorporated so far:...
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How can I protect a DC/DC converter when VIN is floating?
I'm using a L6902 (https://www.st.com/resource/en/datasheet/l6902.pdf) to charge a 4 cell lifepo4 pack (with a solid BMS).
Do I need a diode on the converter output (PACK+) to prevent the converter ...
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Well protected digital input with long wires
I've created simple circuit to protect MCU's digital input against eg. induced spikes. I want to connect quite long wires to this HW and highly probable that this board will be placed close to the ...
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High-Side NMOS Short Circuit Protection: How to Calculate Maximal Allowed Turn-off Time?
I'm about to build a high-side MOSFET switch that can switch voltages up to 150V to an external load (0.5A nominal).
For this application I would like to use the N-Channel MOSFET Vishay SiHH240N6E.
...
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Troubleshooting a Low Voltage Cutoff (LVC) Circuit for Overdraining Prevention
I am attempting to design a Low Voltage Cutoff (LVC) circuit to safeguard against overdraining my 12V rechargeable battery. The objective is to halt circuit power once the battery voltage drops below ...
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Ideas for protecting an sEMG system from external problems
I am designing a pcb to work as a human-machine interface. Here is the simplified schematic:
The idea is to connect a custom sEMG acquisition system to esp32 and also a pcb to control vibrotactile ...
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Will voltage at the inputs/outputs destroy an unpowered opamp?
I have a circuit powered by 12V that accepts an input signal of 0V to 10V. The circuit shall act as a buffer to the signal, with an added LED indicator. In certain circumstances, the circuit itself ...
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Protection circuit for a 12 V Li-ion battery pack
Is there an integrated circuit or a conventional circuit topology to monitor edge conditions of a 12 V battery pack without measuring individual cells within that unit?
A conventional BMS or battery ...
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3 pin Gas Discharge Tube (GDT) - pinout order
I would like to know the reason behind the pinout order of a 3 pin GDT.
GDTs are designed to prevent damage from transient disturbances by acting as a “crowbar” in creating a short-to-ground circuit ...
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One-Way charging connector for 4S Battery
I want to use a connector to charge the 4S Battery of my underwater robot. The connector is the 6 Pin hybrid Cobalt Series connectors from BlueTrail Engineering (https://www.bluetrailengineering.com/...
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How to prevent this op-amp from railing
I have the following circuit:
An input that can go negative (+/-5 V sine wave), and two inverting op-amps. The second op-amp is "current buffered" and is driving the base of a BJT.
Here is ...
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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?.
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Protecting negative power rail
I don't trust my power supply and want to protect my circuitry from over(under)-voltage, but cannot find a clear path of going forward with negative power rail. LDO which I use (LT3094) is rated for ...
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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 ...
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How to select ESD TVS diode? [closed]
This is the following specification of my circuit
Vin 8V to 32V
The breakdown voltage should be 33V of TVS
I don't know what clamping voltage means please simplify it for me
What should be Vc?
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Protection from live casing without true ground
I guess my question is probably trivial with an expected answer like 'It couldn't exist and would be dangerous', but still I keep it around.
Could you build a protection circuit that would protect a ...
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How does a voltage surge/spike affect the wall wart power supply's secondary side?
In the photo, you can observe an old-style adjustable wall wart AC to DC power supply, typically composed of a primary winding, secondary winding, rectifier, and capacitor. If a voltage surge or spike ...
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BJT B-E Zenering: whither the collector?
So, I'm trying to analyze how the circuit in this question behaves when subject to reverse battery (vs. being driven from OUT to IN), and I'm running into a severe snag in the process, though. It ...
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How is SM712 TVS array suitable for use with MAX485 in an RS485 driver circuit?
I have an RS485 driver circuit consisting of a MAX485 driven by an STM microcontroller. I was looking at TVS diodes for basic protection from electrostatic surges from wiring and handling, and found ...
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Operation amplifier input HV protection
I have a setup consisting of 8x AD8428 ultra-low noise opamps on a PCB to measure very small voltages with a noise floor of around some 100uV and a low-pass filter up to 10kHz. The input is connected ...
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Mains transformer input overvoltage protection
You have a mains transformer with switchable inputs, 120V and 230V.
In case somebody switches the input to 120V and applies 230V (which cannot be mechanically prevented, reasonably), the whole ...
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What does the graph 'Short circuit monitoring interval Vs time' mean in this SSR data sheet?
In one of the Panasonic Solid State Relay (SSR) datasheet,the short circuit behaviour is as shown below :
If short detected- > Trip the relay -> Periodically retry untill the fault is cleared.
...
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Not able to correlate the graph and table for the I2t rating in a fuse datasheet
In the datasheet, the I2t rating of a 5A fuse is 0.055 at 10 times In.
Using the same value to estimate the trip time for the 10 A condition, I get 0.0022 seconds. In the graph below, it comes ...
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