I was trying to simulate my incrementer's new carry logic and noticed a new feature in http://www.falstad.com/circuit/circuitjs.html : configurable relays !

You can edit the coil's inductance and resistance, the contact's on and off resistances, the coil's on current and the number of contacts. Still missing is the off current so this is not yet ready to simulate hysteresis. I sent a bug/feature request ;-)

This page already has some links to relay simulators but circuitjs stands on its own and does many things, moderately well but well enough for most cases. I used it a lot to simulate many types of circuits and now even more !

What else do you think is still missing from circuitjs ?

(And for those who might wonder, here is the new circuit for the carry logic, using coils in series instead of parallel as in a previous attempt, so now the current is constant for each slice of 4 bits)

And the link to play at home.

UPDATE

Circuitjs now handles hysteresis ! Here's my first test with the experimental code :-) The new features will be soon integrated in the main dev branch.

The TIM machine was featured at EMF !

You too can build your own machine :-)

Sweet music composed by @Al Williamsl :-)

Relays are so simple :-)

Covers the early electromechanical calculators :-)

The Harwell Dekatron / WITCH calculator, uses Dekatron tubes for storage and telephone relays for the rest. The oldest electronic computer that is still working !

The computational speed is crazy and tested "live" !

More links welcome !