Recent content by Machinia

Alright so first case, let's say best case scenario. Tho object I'm lifting is the same material and diameter as the core, and is a fraction of the length of the core. In which case the force exerted on it at 0 distance would be: F = \frac{B^2 A}{2 \mu_0} This is the formula Wikipedia provides...

Thanks for the link but I did come across that while I was searching. The problem with that formula is it's for a closed magnetic circuit meaning the magnetic flux stays within a core material except for a small airgap. With my problem, the flux is only inside the electromagnet's core, and...

I've searched high and low and come up with a lot of "maybes" and "could be's" and "try this" to a problem which I feel should have at least a few example calculations floating around the internet. The questions is trivial but it seems like the solution is fairly complicated. I'm not looking for...

1 not really, 1 yes. Ok, getting close. @yungman: I understand the importance of transistor matching. It's easy to understand how the whole thing works: If Q2 and Q1 are the same, Q2 mirrors Q1 due to their equal Vbe (With a bit of error due to base currents). But me having no real experience...

Ok thanks to all who replied, this is making more sense and there are some great tips on circuit design. My initial problem was when I first looked at this circuit, I was under the impression transistors could only amplify base currents, as in Ic = beta Ib. So I wondered how did Q1 know how...

Attached is an image of a typical BJT current mirror. The reference current is established by the resistor. We can calculate R with: R = (V.CC - V.BE) / I.REF Now what I don't understand: I know I.C = I.S * e ^ (V.BE / V.T). The collector current is quite sensitive to changes in the...

I ran the circuit through SPICE also and adding/removing the capacitor did nothing to the phase angles... But I'll ignore that for the moment. Instead I'm concerned with the fact that I can't recalculate my real power anymore. Without the capacitor, the current through the circuit = 1.35A @...

I'm pretty certain it's the right value.

Say I have a circuit like this: (R+L+R||L) -----20ohm---150mH------------ |......|...| Vs.......80mH 120ohm |......|...| --------------------------------- Vs = 120V @ 60Hz So I decide I want to add a capacitor across the source of 28.35uF to correct the power factor to 1. Then...