Technology covers many different machines and ideas, so I have grouped my simulators by topic. Choose one to see every simulator I have for it. Mechanisms show how gears, pulleys, levers and belts transmit motion and force. Electricity starts with series and parallel circuits, and electronics goes on to the breadboard and logic gates. Heat engines open up a 4-stroke engine, pneumatics brings compressed air to life and structures show which bars are in tension or compression. Technical drawing trains you to read and draw views, isometric and oblique drawings, dimensions and scales. All of them are free, run in your browser and need no sign-up.