I would like to build an LR circuit. For RC circuits, it is
relatively easy to get timescales on the order of seconds, which
makes demos and measurements easy with simple meters. However, it
doesn't seem to me to be quite so easy to do this for an LR circuit.
A reasonably well-wound coil has an inductance of a few tenths of
henries and a resistance of a few hundred ohms. Hence L/R is at least
3 orders of magnitude away from the seconds timescale and it seems it
would take a pretty unusual coil to bridge this gap.
So I'm willing to settle for having to using an oscilloscope to catch
the action. But now my question is what kind of switch to use?
Conservatively estimating an inductance of 0.1 H and a resistance of
one kilo-ohm (to allow use of an external variable resistor that
isn't dominated by the inductor's resistance), it seems to me that I
need to be able to switch cleanly on the timescale of about 10
microseconds. My experience suggests this is better than what
ordinary mechanical switches can do, which are subject to electrical
"bounces" upon contact. (I'm sure there's a technical name for this,
but you probably know what I mean.)
So what kind of switch should I use? Simple, readily available
solutions preferred. Thanks, Carl
--
Carl E. Mungan, Asst. Prof. of Physics 410-293-6680 (O) -3729 (F)
U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5040 mailto:mungan@usna.eduhttp://usna.edu/Users/physics/mungan/