Recent content by EnEE

if you have more than 2-3 outputs, darlington trans array should be fine. ULN2003/4 for example

in an open circuit the value of resistance is infinity, so voltage drop is zero(there is voltage difference) and i=0

It's depends on your project, especially: 1. max current needed - simple BJT usually designed for low current, IGBT can handle peak current of ~800A, sometimes even more. simple MOSFET usually designed for few Amps(~25-30A), Power MOSFET even ~600-800A(but usually with low power relative to...

I read this article. This is a good example for my question. If the truck need steady current of 65A and 100A for the first 3-4 seconds, I know that for the first second it draw about 150A. Can I use battery with Max burst current of 100A?

because lipo battery sometimes explodes... motors require high current for the first seconds, so I want to know what's cause the battery to explode (and why drones usually use lipo)

Hi, as I know the burst C rating usually refers to the max current allowed for 10 seconds. if I need higher current for 1 second, I can do it? The heat is the problem here?

It's may be difficult... according to general equations it's linear relationship(like here: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html or here: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magcur.html) notice that usually all the computes are in specific area of...

switch in pspice called sw_tclose or sw_topen (N.o_Or N.C switch), both can be found in eval library edit: the emoji stands for normally open, I can fix it but I find that amusing

so, if I wraps the stator with this: http://3.imimg.com/data3/GS/LI/MY-1018839/ss-half-round-pipe-250x250.jpg (there is no contact between the two half-pipes) I can say that Eddy currents have no impact on the efficient of the motor?

Hi, Thanks for your reply. Your side question is my question. the ferro-fluid will remove the reluctance, but what about the side-effects? such as eddy current, iron-losses and faraday cage? the efficiency of common motors is 85-90% due to small air-gap(among other things...), but for some...

theoretical. I said that I ignore mechanical issues(I'll explain in a moment) It's interesting, why they are not meant to interact this way? they air gap is like a huge resistor in an electric circuit, isn't he? so if I want to gain more power I want to minimize the air-gap. I know there is...

Hi, I saw few threads here about air-gap in motors, and I wonder what if we ignore mechanical issues and make an "iron-gap" in the motor. for example: in linear motor(e.g. this cute one: https://www.physicsforums.com/threads/linear-motor-equations.794499/) if we make the tube between the stator...

OK, few thougths... 1.my first thougth about induced currents and lorentz law will not work here 2.If I will use the magnetic potential: μm=0.5⋅μ⋅H⋅H I can compute the force by F=-∇μm H is function of z, so F is also function of z. If I omit ellastic forces on the iron cylinder(can I? maybe...

when you try to find out the current and the voltage you probably use Kirchhoff's laws, those laws derives from maxwell's equations under the limitation that we use the lumped element model(and few more approximations to make it simple). so, you can try to apply the maxswell's equations on your...

you can say that it's at a distance `x` that we don't know. but for a lot of problems you want to omit parameters that make the solution complicated, for example if you want to find the electric field of a charged iron chair, it's may be very difficult... but if you say that you are in the...