This circuit simulates the effect of an inductance. Equivalent operational amplifiers can be used, and the power supply must be symmetrical. The circuit is from a 90's Poptronics.
With this circuit it is possible to add a conductance scale to a common multimeter. The circuit was...
With a touch of S1 this circuit keeps a small strand of nichrome warm enough to light a cigarette....
Mouser Electronics has in stock the MUSBR robust connectors for USB 30 applications from Amphenol. These...