12 Jul
2007
12 Jul
'07
12:48 a.m.
Tony Duell schrieb:
>> Or with a bit more effort you can utilize the
same effect with a NIC
>>
> Negative Impedance Converter?
>
Exactly.
> Network Interface Card? I'd like to see
that...
>
The electronic circuitry talked abaout here is decades older than
network cards.
I would have thought most Network Interface Cards
contained enough
circuitry to flash an LED :-). The problem might be getting access to
it,.as it's likely to be hidden inside large chips...
Or with two NICs, or with about 5 or 6 transistors. The version you get
with a single OpAmp is assymmetric, it has different
g-factors on each port. With the Real One(tm) the two ports can be
swapped. This is sometimes necessary in filter circuits.
The g factor you mentioned above is actually 1/<impedance>^2 which means
you get pretty large inductors from small capacitors.
The transformation from a coil to a capacitor is rather uncommon because
it will produce pretty small capacitors from huge inductors, and more
important, the quality is lousy as it is very difficult to produce
high-Q coils with high inductivity.
--
Holger
> or a gyrator.
>
A reciprocal impedance converter circuit. Basically, you connect an
impedance to one side of a gyratorm, and the other side appears (to the
rest of the circuit) to be 1/<that impedance>. It can make capacitors
look like inductors and vice versa.
You can make one using an op-amp.