need help in circuit design for current fault

[ehab_salama91]

i want to make circuit for using it to indicate if there is fault in the current moving in overhead cables by sensing the di/dt in the current .plz help me guys

 

[unclejed613]

can you be a bit more specific? overhead cables.... RF, AC power, DC power, audio, video??????

 

[Grossel]

If you doesn't just go and saturate the iron core, here's a simple solution:

 

[unclejed613]

for that matter, a resistor inline with the terminals going to the op amp would be simpler.....
looks like i need to come up with an award for strange/vague questions.... the Wile E Coyote Award and the Marvin the Martian Award just doesn't seem to apply here..... somebody help me out with a comedian or cartoon character whose trademark is "Vague"

 

[ben7]

Most high current ammeters -10A and up- use a clip-on current sensing transformer instead of a wasteful dropping resistor.

-Ben

 

[ehab_salama91]

thanks for replying me
but i need to design a circuit to indicate that there is a fault in the overhead transmission line current

 

[blueroomelectronics]

From power transmission lines?

 

[ehab_salama91]

yes blue from power transmission line

 

[blueroomelectronics]

How do you plan to couple it to the wire in question? A kite?

 

[ehab_salama91]

i will use hot stick to put the device on the transmisson line and i think i will use current tansformer

 

[blueroomelectronics]

What is a hot stick? Transmission towers are very high, you can't reach the wires from the ground.

 

[cobra1]

A hot stick is an insulated pole, there about 25ft long.

Not sure where the OP is from, but here i think it would be deemed illiegal to attach a wire to a power line and have it connected to some peice of equipment, 44,000v is not something you want to plug into.

 

[blueroomelectronics]

Ain't going to reach a 100+ foot hydro line, it's also dangerous and stupid. This has got to be an ill conceived school project.
**broken link removed**

 

[ehab_salama91]

yes cobra u r right that is the hot stick

 

[ehab_salama91]

its used for 24 kv transmission line

 

[blueroomelectronics]

Is this a school project?

 

[cobra1]

Surely it cant be a school project, it could never be tested, it would be unsafe, and ultimatly unuseable. i would assume these were parameters needed to be considered when choosing the project.

 

[ehab_salama91]

no its not school project but i really need to do that

 

[blueroomelectronics]

no its not school project but i really need to do that

Ok, I'll bite. Why do you need this?

 

[cobra1]

I must admit im also curious as to why anyone would want/need to do this. by the way you already have a current detector on your mains supply, switch the lights on, if they come on your good, if not youve no current