Signal generator
A bench signal generator on the canvas: sine, square or triangle, at whatever frequency and amplitude you set.
Two pins and four knobs, like the box on a real bench: wave picks the shape,
frequency and amplitude set the swing, and offset sets where the middle of that
swing sits. It behaves as an ideal voltage source between OUT and GND, holding its
waveform whatever is hung on it.
Pins
| Pin | What it does |
|---|---|
OUT |
The waveform, as an ideal source. |
GND |
The reference the waveform is measured against. |
Properties
wave: sine, square or triangle. frequency: in hertz, 1000 by default. amplitude:
the peak swing either side of offset, 2.5 by default. offset: 2.5 by default,
so the stock settings give a 0 V to 5 V swing, exactly what a logic input wants.
duty: the square wave's duty cycle, 50 by default.
What the model gets right
The waveform is evaluated by the analog solver rather than stepped by the part itself, which is what lets the solver put a breakpoint exactly on every square-wave edge and land on it instead of integrating through it and smearing the edge. An amplitude of 2.5 on an offset of 0 gives a signal that genuinely swings to -2.5 V, which is how the negative half of an AC circuit is simulated here.
What it does not model
No output impedance beyond an ideal source, no distortion, no amplitude or frequency drift, and no sawtooth. The function generator beside it is the same idea with two of those put back: a real 50 ohm output and a ramp, with knobs on its face for both.
Being ideal is a bigger claim than it sounds: this source holds its waveform into a short circuit, delivering whatever current that takes, and there is no rise time, no noise, no jitter and no upper frequency limit beyond what the solver's step can follow. It is the right part for driving a node and the wrong part for a lesson about loading, which is what the function generator is for.
Common mistakes
Assuming the default 0–5 V swing is the only option. For an AC circuit that should
swing negative, set offset to 0 rather than leaving the beginner-friendly default
in place.
See it in action
RC filter on the scope and RL filter on the scope both drive their networks from a signal generator and read the result on the oscilloscope. Open them at /templates.