Development Trend of Residual Current Circuit Breakers
The paper deals with the directions of the state-of-the-art changes in the field of residual current circuit breakers, with particular emphasis on standards changes due to new requirements of environment, reliability of operation, operation at high frequencies, and use of voltage-dependent switches.
Protection switches, or residual current devices are in practice a widely used way of protection against indirect contact with live system parts, fire, and direct contact with live components, in various types and installation executions. The following types of installations can be distinguished: housing and similar installations, and industrial installations. And the executions refer first of all to the earthing systems, i.e. TT, TN and IT systems. The field of use of residual current devices is therefore wide and important enough to have to permanently follow the development. The state-of-the-art is defined by the state of standardization, therefore the paper gives in the first place an analysis of standards, with an emphasis on the IEC, EN and SIST standards, and the terminology usually used for individual product is added, too. In the continuation the actually usual use of residual current devices has been represented. The central part of the paper is dedicated to the development trend of these products, where the changes in market requirements should be emphasized, and as a result also the requirements for changes in the standardization area.
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solution for a current circuit lab?
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can we use to drive a low current circuit by using a relay ?
it is always that relay is just used to drive a high current circuit by a low current circuit.
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How to control low power circuit with high power circuit?
I have a simple circuit that runs 12V @ 5A. There is a power source and a load. I would like to somehow incorporate a device into this circuit that would allow me to control a low current circuit. This would be done in such a manner that that only when the main load (5A) is on the low power circuit is on. Keep in mind that the low power circuit serves as a check if the high power circuit is on an operational. Flipping a switch will not do it. I need to know that my 5A load is working when I flip that switch.
What can I use? Relay will not work as I will melt the coil with 5A.
shroudingsteel:
That would work, but if the 5A load burns out the LED will still be on. I need something in series, so led comes on only when load is on.
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How can I make this circuit work?
The circuit is supposed to function as so:
1) Press the button to close the - path to the Timer.
2) The Timer starts.
3) The NPN is saturated by the + coming from the Timer creating a bypass for the - flow so that when the button is released, the connection is still closed.
4) After a set time, the Timer expires removing the positive charge from the NPN base and subsequently removing the button bypass.
This is the timer:
http://www.electronickits.com/kit/complete/timers/canck002.htm
The timer draws less than 7mA and positive path is switched while the negative goes straight through.
This is my current circuit:
http://ericpersonal.shutterfly.com/pictures/11
I can't figure out why the transistor won't stay saturated when the button is released. Some direction beyond, "Your circuit was badly designed," would be greatly appreciated.
Thank you!
Eric
VLP, thank you very much for your response. It would be wonderful if someone could check out my updated schematic to see if I've got it.
http://ericpersonal.shutterfly.com/pictures/12
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physics 2 chapter 23 alternating current circuits problem... help!?
two ac generators supply the same voltage. However, the first generator has a frequency of 1.5 kHz, and the second has a frequency of 6.0 kHz. When an inductor is connected across the terminals of the first generator, the current delivered is 0.30A. How much current is delivered when this inductor is connected across the terminals of the second generator?
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Can I change the size of a current electrical circuit by adding a second set of wires to it?
I need to change the circuit size to a much larger size! If I have a current circuit at 30amps and I have another set of wires running to the same location not used, can I just change the breaker and add these wires together to increase the circuit size if needed?
Example would be two (2) seperate sets of 10 gauge wire would now equal 60 amps
What if the wires were of different sizes such as 6-2 wire & 10-2 wire. Could I put this on a 80 amp breaker?
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physics 2 alternating current circuits?
A 755-loop square armature coil with a side of 11.5 cm rotates at 55.0 rev/s in a uniform magnetic field of strength 0.45 T. What is the rms voltage output of the generator?
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