Resistor in a simulator, free to use

Reference

Every one of its 2 pins

What it does

1

Either end. There is no "in" side.

2

The other end.

This part

What it does

A resistor has no idea which way around it is wired. Each of its two pins is driven from whatever the other pin sees plus the drop its own current sets, which is Ohm’s law applied with no special cases: the same part is a pull-up to the supply, a pull-down to ground, the top half of a voltage divider, and the series limiter in front of an LED. It does not need a shared solve to behave, so on its own it never forces anything else on its net into one; wired next to a capacitor or into a 555’s timing network it joins that solve properly, as a plain conductance. There is no destructive limit modeled: pick a value far too small and the part reports a current a real resistor could not survive, rather than failing, which is a safe way to see the mistake on the probe without losing a part.

Reference

The one property you can set

Property

Default

What it means

value

1000

the resistance in ohms. 220 for an LED, 10 000 for a pull-up, whatever a divider or a timing network calls for.

How it is modeled

What is true about the Resistor, here

What is modeled

A resistor does not need a matrix to behave, so on its own it never creates an analog island. But when one reaches it (the series resistor of an RC network, the two timing resistors of a 555), it joins the island and is stamped as a conductance instead of passing a Thevenin equivalent along, and its current probe still reads the same current either way.

Not modeled

No tolerance, no temperature coefficient, no power rating. A resistor here will happily pass an amp through a quarter-watt value and simply report the current; it will not heat up, drift or fail open. No Johnson noise, no parasitic inductance or capacitance, and no preferred-value grid: any positive number is a resistor, where a real bin holds E12 or E24 values only.

From Resistor, in full.

Projects