Protection Definition and 135 Threads

I had a circuit of buck convertor that converting 24V dc to 4V dc. 24V dc input is from a PSU (Meanwell's PLN series), once it go in, it connects to a Polyfuse, then polarity diode (in series), then Common mode choke, then it's my converter's input capacitor (35V 47uF AVX's TAJ series)...

Hi,I study protection of superconducting coils.I adopt heaters to protect coils.The circuit is in attachment. There are 6 coils,so I use 6 quench heaters.I want to know how I choose the heaters? It must do the Quench Heater Simulation for protection of superconducting coils before...

hi there I am have 4 simple question please help me 1.In the event of single phase – to – Earth fault how does each of these methods influence the fault current system voltages 2.What would happen in the event of loss of communications during a fault condition? 3.How would this compares...

OK, so people say that wearing white is better than wearing black in the sun because white reflects light whereas black absorbs light. But at the same time it is said that black is better for sun protection (for example, darker skinned people are much less likely to get skin cancer than...

Use with good judgement. :smile: http://www.obamacondoms.com/

what are the advantages and disadvantages of different types of transformer grounding -with regard to system protection and fault current reduction? we have the following grounding types YN - YN YN - Delta Delta - YN Delta - Delta where can i find a good resource that explains this?

Hi, I have a switch connected to a motherboard. During ESD test with 8000kV (directly on the switch) the ESD spike caused my system to reboot, and I need some kind of surge protection betwee nthe switch and motherboard. I am not sure what I need to look for? Can anyone suggest a...

i am working at a thermal power station as a summer tranii in india...today my instructer told d protection of geneartor he tells us over current protection ... i am not satisfied ...is dere any over current preotection exists or not?

hi guys >>>> i have 4 giga transcend flash memory , and it was working in normal way , but now it doesn't accept to write or delete any files , giving message " the disk is write protected" ther is no hard lock on the flash ... also i tried to format it ...but it didn't accept for the...

Hello everyone , I am still new to the protection field so i would appreciate if you can help me with analysis of the following, A 13.8 Kv OHTL was cut and fell on ground , the cable was still live although being protected by Earth fault relays and Over current relays(Instantaneous and...

I have some problems regarding spyware, malware and stuff like that on my computer. The browser runs much slower then normal and pictures cannot be adequately displayed. The XP Protection program recommends that I install their software but that will cost $50. Any equivalent software on the net...

As you know, for Earth fault protection of electrical system, the residual current measurement is often performed using the three line CTs. But in this case the protective relay must be slightly time-delayed to avoid spurious trips caused by circulation of a false zero sequence current following...

Our atmosphere? Our atmosphere protect us from the cosmic rays what it consist of(the cosmic rays and the atmosphere)? How much is its power? How it (the atmosphere) stop these rays? What happened in high level of the atmosphere to stop it? What are the best gases (in the atmosphere) that...

I did think about high guard armour, but that is not invented yet, any other full body protection is rather cumbersome, so what are the options.

In a low voltage substation, including two incomings and a coupling circuit breakers, incoming C.Bs are connected to two individual power transformers which are fed from upstream medium voltage system. The two low voltage bus bars are equipped by a fast auto transfer system which is considered...

Is there any Short circuit protection diagram designed for power supplies which the current doesn't drop below 1A? Can you show me any?

In an extra high voltage substation, the output overhead lines protected by standard protection system. That protection system contains high quality main and backup distance protection, sync/auto reclosing relays and separated static relay that specified to line circuit breaker which is named...

I didn't know where to put this since it pertains to both chemistry and biology so i put it here. One time i accedently spilt 31.45% concentrated HCl on my skin and didn't notice it right away but then i saw this fuming drop on my skin and i immediately washed it off, it never tingled, burned...

"Retroactive War Crimes Protection" http://www.nytimes.com/aponline/us/AP-War-Crimes.html?_r=1&oref=login So hypothetically, if they had (which they didn't) done something horribly inhuman and grossly illegal, they would be retroactively immunized. Of course there's no reason to be suspicious...

Why Zinc is so commonly use coat metals such as steel? I know that its a good corrosion resistant metal to use but what properties of zinc make it good to use under normal atmospheric conditions? Does it have to do with the oxide layer that it forms around it?

What did iron do to protect copper? 1. I know it has a stronger reductive power than copper, which means it has more tendency to oxidize. Question: So, iron reduces O2 and H2O instead of copper? Or does it also reduce the copper that oxidized? Could someone explain me what really happens?

Hi All, I'm replacing a switch in a piece of equipment. I'm looking at the circuit diagram and the actual circuit, and I notice that the diodes in the circuit aren't wired as they are in the diagram.:smile: The HI signal is dc from 0-1 Volt and LO is ground. Is there going to be any...

On standard road bike tires sometimes they put a soft/flexible kevlar layer to protect against puncture. I was thinking about putting in in hard/rigid kevlar layer to also protect against puncture, I know that this will make the actual tire stiffer and harder to deform, which could be a bonus...

Just thinking about those people like Eminem who people keep trying to sue, and end up having to pay huge amounts of money in legal bills to defend themselves. I was wondering if there are any laws to protect someone from having to pay this if they are found.. (whatever the civil-law equivalent...

I am designing a 500mA source circuit using a npn and pnp transistors. How can I protect the pnp if the output is shorted to gnd. Both transistors are in common collector configuration.

Hi there, Can anyone tell me if this is right. If I were to have an aluminium boat and I want to give the hull cathodic protection what metal would I use. I said that I would use a more active less noble metal such as zinc. by placing the zinc it becomes the sacrifial anode and the hull is...

In 2002, President Bush signed into law that requires abortion doctors to attempt to save babies born alive during an abortion. Reading my local news today, this act will be enforced much greater since our government is choosing to take on more morality issues. The beauty of this law (IMO) is...

A gyroscope of a certain size is mounted midship of an SUV of about 2100 lbs, and the gyroscope was setup to accelerate if this SUV accelerated. Now normally if a SUV makes a 90 degree turn past 35 miles per hour the driver looses control and or the vehicle rolls over. How fast would...

I read in alocal daily that some bacteria have around 1000rads. Can we take that dna and put it in humans and make them resistant to radiation. Then can we use nuclear power everywhere(like planes, cars, etc)

Hi, Has anyone heard of a layer of boric acid being used as a heat shield? I know it is often used in solution and other composites to act as a fire retardant, but what I'm looking for is any reference to boric acid, by itself, being used as an insulator. Maybe like a layer of boric acid...

Hi, Has anyone heard of a layer of boric acid being used as a heat shield? I know it is often used in solution and other composites to act as a fire retardant, but what I'm looking for is any reference to boric acid, by itself, being used as an insulator. Maybe like a layer of boric acid...

okay, I'm having an argument at home, we're all 2nd year engineers and have different views on the galvanizing process. the way i see it is metals are dipped in zinc (anode) and are connected to the metal (cathode). a reaction takes place which provides cathodic protection to the metal if the...

I'm trying to use this protection cct. What I do know is that (dv/dt)max = 50 V/us and (di/dt) = 10A/us (us = microseconds) R = 1 ohm, R = 5 ohm, Vcc = 120 V Can anyone give me an idea how to find the right L and C ? Thanks

Help. I need help in designing a "safe" that gives me heat and fire protection. I will be using an skins of steel and need help in selecting the core materials. I am trying to protect electronic media so the heat gain inside has to be close to minimal. I am also trying to keep overall wall...

i have a problem can somone help please, i have this message with a blue screen, STIMON caused a protection fault in module user.exe at 0003:00009e46 i have a printer and scanner connected anthon 1.8