Stack Exchange Network

Stack Exchange network consists of 174 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 [circuit-protection]

A device, components, or safety measure designed to protect circuits from overvoltage, overcurrent, a combination of these; or the theory of same.

0
votes
1answer
38 views

In a DC circuit, are there any reasons for wiring overcurrent protection such as fuse or pptc PHYSICALLY near the load?

In a DC circuit, are there any reasons for wiring overcurrent protection such as fuse, pptc, etc.... PHYSICALLY near the load(or inside it)? By wiring "physically near", I mean in the power wire going ...
0
votes
1answer
45 views

Protect signal from noise in Arduino

I am trying to send a signal from the Arduino to a relay to open a switch. My problem is that my Arduino will be near the AC power lines. I searched for how to prevent the noise to ruin the signal ...
2
votes
7answers
2k views

Opinions on what I've come up with for a 12 V-to-5 V automotive circuit?

Is this a solid solution for an automotive 12 V-to-5 V circuit to power an ATtiny? I've been trying to come up with a solution for my needs that can handle the automotive environment that is so scary ...
0
votes
3answers
113 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 ...
0
votes
3answers
80 views

How do I get 5V 10A output from a 3.7V li-ion battery for 64x16 led matrix display module?

Please I am new to electronics and new here. I'm doing a project which involves the use of a 18650 li-ion battery (or two as may be the case) to power a 64x16 led matrix display module which (...
1
vote
1answer
44 views

Triggering of TRIAC for Crowbar Protection

I am reading the datasheet of TRIAC (T1235T-8G). I am not sure how to trigger the TRIAC and what do they mean by ...
0
votes
0answers
38 views

Is it a bad idea to connect two Li-ion batteries in parallel? [duplicate]

Suppose I have two Li-ion batteries for smartphones. One could say that if they are connected in parallel, then the voltage given to the device would be the same, but the capacity would be doubled, ...
1
vote
1answer
75 views

PoE and Adapter Power Supply Design

I am designing a power supply cicruit. The circuit will get it power from PoE (preferably) and external adapter (7 - 12V). For ...
-3
votes
2answers
96 views

This is very confusing [closed]

Why does it hold the voltage constant? Isnt it supposed to act as a ideal diode during forward bias ie behave as a closed switch?
1
vote
2answers
115 views

Inductive load shorts power supply

I had a hair-brained idea the other day and put together the attached circuit. The problem: the instant I push the switch to place a voltage across the inductor, the power supply shuts down. Clearly ...
1
vote
1answer
68 views

Fire danger when using IoT components

I am automating my house using components like ESP8266, 220 to 5V converters, relays etc. How big is the risk of a fire starting from a component malfunction and how can I mitigate this? What should ...
0
votes
1answer
38 views

Calculating energy of transient/surge handled by metal oxide varistors (MOV) or surge suppressors?

As I get to know more about the MOV operation, there are more things needed to understand. My MOV (V420La20AP) has Varistor voltage of 680 Vrms (10%) at 1 mA, and maximum clamping voltage of 1120 V ...
0
votes
0answers
46 views

When to use a 2 pole circuit breaker over 1 pole

We are currently designing a product that connects to 230VAC mains power (single phase) (South Africa). It has a simple 12v switch mode power supply that runs the electronics. We want to put a Circuit ...
0
votes
0answers
65 views

electric fence fuse

I have built a circuit like this. It is powered by a 12V car battery that gets charged through a solar panel, and it uses a car coil to create the high voltage. The designer of the circuit suggests to ...
1
vote
1answer
113 views

Full Load Amps vs General Purpose Amps

http://www.carlingtech.com/sites/default/files/documents/M-Series_Details_%26_COS_021114.pdf This circuit breaker have two different current ratings, depending on amperage range: Full Load Amps and ...
0
votes
1answer
36 views

Wiring Up a Li-Ion Battery (Band 2)

I have a Li-ion battery that I pulled from a MS Band 2. It comes with a protection chip, which I am having trouble with. The chip has 4 accessible pins, labeled "P+, K, T, P-". I've tried every ...
-1
votes
1answer
73 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 ...
1
vote
0answers
56 views

How to protect a buck DC-DC being backfed from the load (e.g. a battery as a load)?

Background I want to design a DC-DC adapter that is foolproof and has some protections in place so that it doesn't accidentally damage the somewhat expensive equipment downstream. Here's what I have ...
0
votes
1answer
54 views

Can high power USB destroy older devices? [duplicate]

My brand new pair of bluetooth headphones stopped working after charging them with a 2.1 Amps USB outlet. I can't turn it ON anymore. I do see the LED battery Green then I charge it though. I noticed ...
2
votes
0answers
54 views

High power / high current clamping circuit

I am looking for ideas on how to clamp high energy surges in the input of a high current / high power system. The input to the system is 24V. During steady state, the system sources 85A of current ...
0
votes
3answers
92 views

What can happen with the PCB foil while SMD resistor destructive overheat?

I need to protect the gate driving circuit by putting the resistor between the gate and the control circuit: During the testing of the mockup MOSFETs can go be destroyed which leaded to high voltage ...
0
votes
1answer
39 views

One-time fuse for disconnecting/breaking signal path

I am looking for an IC solution, ideally, but alternatively also could use a tiny circuit that would allow to accomplish the following feature: Trigger an event by MCU that will fuse-out/disconnect ...
0
votes
1answer
51 views

How to fuse batteries connected in parallel?

I have two GEL batteries 12V/130Ah and want to connect them together in parallel. Currently I have one battery in the system and it is fused on the positive wire before the isolation switch. I ...
0
votes
1answer
29 views

Integrated Circuit Epoxy Outer Molding [duplicate]

I'd like to know whether flame retardant epoxy resins, the FR-4 brominated type for instance, are used in the outer molding for integrated circuits or whether it's just a plain epoxy resin. ...
0
votes
0answers
95 views

ATX Power Supply trips with DC Motor

I am using an ATX switching power supply as a power source for my motors and air compressor. Specifications of the PSU is: Type: ATX 12V Model: 850UB Vac~ input: 230V, 5A, 50Hz Vdc MAX DC Output: ...
1
vote
0answers
51 views

Tp4056 overcharging

I have combined five 18650 cells in parallel and i am charging them using a single tp4056 circuit . The problem i am facing is that the module keeps on charging. I had to stop the charging manually at ...
1
vote
2answers
66 views

protection of industrial analog input modules for high-voltage signals

I'm looking at ways to design a multi-functional analog input that can take both voltage and current inputs for industrial applications. The voltage signals are in the 0-40V range and the current ...
0
votes
1answer
36 views

Do i need to protect a DC adapter from current spikes (produced by buck converter)?

I wonder if i need to protect my ac adapter, which has over-voltage, over-current and short-circuit protection. The ac adapter feeds a buck-converter which uses a low-side n-mosfet switch ...
1
vote
0answers
55 views

TVS protection burnt too easily

It's about an year that I'm using TVS diodes to suppress spikes from the AC motors (240V - max 240W) that drives my roller shutters and protect the solid state relay that actuate the motor. What is ...
1
vote
1answer
69 views

Bypassing DSLR battery to power camera from power supply cheaply with bidirectional optocouplers

I am trying to power my Nikon DSLR with a permanent power source instead of the battery for long captures (overnight) without buying the overpriced battery adapter. I can't simply connect a AC-DC ...
1
vote
3answers
78 views

Is it necessary to add fuse protection (at the inputs) when using multiple DC-DC converters?

I would like to know if it is necessary (or recommended) to add fuses at the inputs when using multiple DC-DC converters. I have attached a quick schematic to illustrate what the design would look ...
1
vote
1answer
67 views

Powering module directly from LiPo Charger with LiPo connected

I have a GSM module (Particle Electron) which has pins for powering it from a LiPo battery. The pins accept voltages from 3.6V to 4.4V. The module can also be powered from 5V supply through another ...
1
vote
2answers
52 views

Can an array of fuses protect a PC port from damage?

I'm paranoid right now because I made another circuit meant for the parallel port of the PC. While all my previous experiments involving the port were successful (except for one experiment I made a ...
1
vote
2answers
78 views

Protecting microcontroller output

I'm designing a very simple microcontroller breakout board. I wonder how can I protect microcontroller output pins against accidentally connecting another signal to one of them and burning the pin's ...
0
votes
1answer
104 views

Microwave oven with no heat, Bad design or wrong component choice? [closed]

Few days ago, my Magic Chef MCD990B microwave oven magically passed away randomly and so suddenly that I didn't even have time to say goodbye, not that I have used it heavily or considered it as my ...
0
votes
1answer
143 views

How do I protect an electronic circuit

I’m beginner in electronics and i have project for grow LED light and i want to connect LED with timer. My inquire how I protect my circuit. My circuit Adapter 12V 1.2A Timer (5-20v) up to 5A 2 * ...
0
votes
1answer
117 views

Multiple DC power source to the board protected by schottky diodes

Provided is the DC power supply block to the micro-controller development board from one of the leading MCU manufacturers. I need help to understand this arrangement. I will use two sources V5-...
3
votes
0answers
126 views

Dimensioning SCR crowbar circuit

I need to dimension an SCR crowbar circuit to reach a certain level of protection against overvoltage, without increasing much the complexity of the circuit of my control card. The need is to protect ...
0
votes
1answer
156 views

12V 12A resettable crowbar circuit

The idea is to protect the input stage of a control card from improper power supply connection. The power supply is a standard desktop AC-DC power adapter (Meanwell GST160A12) with inbuilt shortcut, ...
6
votes
1answer
483 views

TP4056 module parallel output

this is my first time asked on stack exchange, please bear bare with me. Anyway, I created portable monitor using multiple TP4056 as battery charger & protection circuit. But I'm not sure it's ...
0
votes
1answer
58 views

Earth& neutral voltage detection

Can someone suggest me circuit to detect the earth to neutral voltage. I would like to trip relay coil using microcontroller if earth to neutral voltage exceeds 3v. There are device RCB and RCBO ...
1
vote
3answers
109 views

Not understanding why in overcurrent protection only a certain section will isolate (why not the whole system)

I'm having an issue understanding a simple concept for faults. I understand the principles of how the relays cause the circuit breaker to open etc when a larger current goes through them to provide ...
1
vote
2answers
123 views

How do protection circuits deal with instantaneous voltage?

For protection components such as Varistors and Diodes, when an instantaneous fault voltage is applied - how to do these devices protection before the device has time to conduct. For example, a ...
0
votes
1answer
179 views

DW01 2s protection

I want to protect 2 18650 batteries with single DW01. The problem is how to increase the protection voltage on DW01 . I have read that I should use voltage divider on VCC pin. I just want to make sure ...
1
vote
2answers
213 views

How to calculate the exact delay of a delayed ON/OFF imlemented by low pass filter

I am trying to implement a delayed ON/OFF by using low pass filter implemented by a capacitor and a resistor. I can find the R,C, and cut off frequency by using calculators I found in the internet. ...
1
vote
1answer
99 views

Protecting against reverse polarity

I'm building a JTAG programmer for the old Motorola 56k devices and I want to add some circuit protection before having some boards built. I'm more of a firmware/digital guy, but here's what I came up ...
0
votes
2answers
160 views

Protecting microcontroller digital output pin from ESD, reverse connection, and other possible user error

I want to protect an output pin from ESD, reverse connection, and other possible user error that might cause damages to my circuit. This pin output pulses depend on the amount of water passing through ...
1
vote
1answer
87 views

Opto-coupled EIA-422 receiver (understanding suggested circuits)

I am looking at a standard for communication of marine electronics (NMEA). The standard is electrically essentially EIA-422 but it prescribes opto-coupled differential receiver pins without connection ...
1
vote
5answers
119 views

Using battery to operate a DC load

FOLKS, am a learner. This is the problem am trying to get around. what would happen if I use a 200amp 12V battery to run a dc standing fan of say 2amp power draw or a piano of same rating or any ...
-1
votes
2answers
205 views

What are good alternatives to the dw01a used with TP4056?

Currently I have a 18650 battery charge and discharge circuit in my Board design as a "Emergency fall-over power. And I have some problems with it. First problem I see is that while the battery is ...