bedini, the daftman SS charger & MHOP

[TinselKoala]

So don't buy one. Nobody is twisting your arm.

You might ask Tinman about his scope, maybe it would be more to your liking. It's only about seven times more expensive than the basic Hantek...

Here's a recent screenshot from my old Link parallel port scope, made in 1997, running on Windows 98:

(And I think the Hantek probably has better software! This scope can't do trace multiplication.)

[TinselKoala]

i've got two 2n3055s with your name on it when i get the chance 

thx!!

I'm thinking that it would work even better if you used ultrafast diodes instead of 1n4007. The UF4007 is a bit faster (75 ns), but my "current" favorite is BYV26E, 1kV 1amp 75 ns recovery time, avalanche rated, inexpensive.

[qtrhack]

my "current" favorite is BYV26E, 1kV 1amp 75 ns recovery time, avalanche rated, inexpensive.

just ordered me a bunch   thx again!!

[qtrhack]

What is an L/R time constant?

http://www.learnabout-electronics.org/ac_theory/dc_ccts45.php

The LR Time Constant.

When a current is applied to an inductor it takes some time for the current to reach its maximum value, after which it will remain in a "steady state" until some other event causes the input to change. The time taken for the current to rise to its steady state value in an LR circuit depends on:

•The resistance (R)
This is the total circuit resistance, which includes the DC resistance of the inductor (RL) itself, plus any external circuit resistance.

• The inductance of L
Which is proportional to the square of the number of turns, the cross sectional area of coil and the permeability of the core.

[MileHigh]

Yes and if you played the animation you see it in action.  The screen cap is attached.

There is one mistake on that page that you repeated.  It's really the "L/R" time constant and not the "LR" time constant.  You don't want to confuse it with the RC time constant.  The first is division, the second multiplication.  Since the L/R time constant and the RC time constant have the same exponential waveform, you see it everywhere on scope traces.  If you randomly watched 10 clips that have a lot of scope shots done by typical experimenters around here, chances are you will observe the exponential waveform in at leas a few, if not most, of the clips.

The time constant can be a microsecond, a millisecond, a second, or a day in length, but they still have the same waveform.