Filter Wiz PRO - Active filter design software for lowpass, highpass, bandpass and bandstop electronic filters using resistors, capacitors and op amps. Provides Butterworth, Chebyshev, Elliptic and Bessel Approximations to order 20, with a variety of circuit choices.
eSketch - Electronic circuit simulator with rapid schematic capture and many simulation features including Monte Carlo analysis, Parameter Sweep analysis, Pole-Zero calculation, multiple voltage probes, input impedance, real and ideal op amp models.
Resistor Color Coder - Determine resistor color bands from value, or value from color bands.
