A number of the radio shack science fair electronics learning kits (at
least 150-1, 160-1, 200-1) and some other equivalents (at least of the
200-1) have a (second) transformer, (some) with the labels 4K on one leg
of a center-tapped side and 2K on the other (not center-tapped) side. It
also has the label "input transformer".
Suggestions for a (hopefully inexpensive) reasonable match/replacement
for this part, that is readily purchased somewhere greatly appreciated?
Thanks.
Last I checked, Mouser had a page of "subminature audio transformers" or
something like that.
The specs on these things are variable enough that something nearby will
probably work (a factor of 2 or thereabouts). For a couple of different
manufacturer's parts, the impedance (and turns ratio) matches, but, for
the cheap guys, you'll find the actual inductance of the windings shows
that they put the minimum amount of wire in there. Great leeway can be
had with the minimum and maximum frequency response. (Lower inductance
windings will end up with a higher value for the low frequency limit).
They'll spec the frequency response, but usually don't spec the winding
inductances (which can vary with the core material, and with a bunch of
other nonlinear crap when in operation).
So a good manufacturer's 1k ohm transfomer might be the same as a
cheap guy's 2k transformer. these days, most of this stuff is some
job shop in China, so "it's suck it and see" if you're buying a one off,
retail
Mark Zenier
[email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)
