Recent content by Undacuva

I understand the 1st law of thermodynamics developed as a generalization based on experimental observations, in that an exception has yet to be found in thousands of situations, so it is considered to hold true in all possible situations. If that is how it developed, is there any other theory or...

Hi, I understand you can induce an electrical current by passing a magnet through a copper pipe. If so, why do generators (and motors for that matter) use coils in stead? Do coils allow a stronger current or greater efficiency? Where can I go to find out the most energy-efficient design for a...

Hi folks, I need to get a super capacitor which will be charged by a car battery and then connected to let out a massive pulse. (Yes a bigger pulse than my 450CCA battery can give). But first I need to work out how much capacitance will be needed. I'm not sure of the formula. Thanks

Hi, I'm looking for a high power resistor. I just got confused over some nomenclature I haven't seen before. (Yes I'm a beginner). I'm seeing resistors named like this: "3R9ohm"and "4R7ohm" I know what R is in V=IR. But in the rating of a resistor? Can someone help?

Hi everyone, Thanks for the responses. It seems that no-one has any issues with my winding method. What about increasing the voltage? Is there any use in that? Or could I sacrifice voltage for higher current?

Hi everyone, I have a 12mm long hard ferrite core that I want to use as an electromagnet. I have wound it with 0.8mm copper as tightly as I can by hand, in a single layer, but the field is not strong enough. I have placed another coil over that first coil, and then a third coil, each in...

Hi Folks, Just to avoid confusion, I need to send pulses something like 1ms duration (or shorter), maybe 2 or 3 times a second down a wire coil around an alnico magnet to reverse its polarity. This process doesn't require heating the magnet at all. Just a strong burst of electricity. The...

Hi, I need to know how to calculate the power level and pulse width required to revers the polarity of a rod or bar shaped alnico magnet, depending on the width. I also don't know whether to use AC or DC power. I'm prototyping an invention and it needs to be as power efficient as possible.