https://teddyrookbook.com/inventors/from-scratch/Recent content in From Scratch on Teddy Rook Bookhttps://teddyrookbook.com/img/share.jpghttps://teddyrookbook.com/img/share.jpgHugoenhttps://teddyrookbook.com/inventors/from-scratch/lemon-battery/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/lemon-battery/Two different metals in a sour juice make a small voltage; cells in series add their voltages. From Scratch · Inventors Ladderhttps://teddyrookbook.com/inventors/from-scratch/electromagnet/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/electromagnet/Current in a coil makes a magnet; more turns and more current make it stronger, and an iron core multiplies it. From Scratch · Inventors Ladderhttps://teddyrookbook.com/inventors/from-scratch/simple-motor/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/simple-motor/A current crossing a magnetic field feels a push, F = BIL; arranged right, the push keeps a wire spinning. From Scratch · Inventors Ladderhttps://teddyrookbook.com/inventors/from-scratch/hand-generator/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/hand-generator/A changing magnetic field through a coil makes a voltage; faster changes and more turns make more. From Scratch · Inventors Ladderhttps://teddyrookbook.com/inventors/from-scratch/telegraph/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/telegraph/A key closes a circuit; an electromagnet far away clicks; dots and dashes carry letters. From Scratch · Inventors Ladderhttps://teddyrookbook.com/inventors/from-scratch/filament-bulb/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/filament-bulb/Current heats a thin filament until it glows; in air it burns away, so lamps need a vacuum or a gas without oxygen. From Scratch · Inventors Ladderhttps://teddyrookbook.com/inventors/from-scratch/crystal-radio/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/crystal-radio/A coil and capacitor pick one station; a diode turns its radio wave back into sound you can hear in a sensitive earphone. From Scratch · Inventors Ladderhttps://teddyrookbook.com/inventors/from-scratch/printing-press/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/inventors/from-scratch/printing-press/Backward metal letters, set and justified, inked and pressed, print a page the right way round, hundreds of times a day. From Scratch · Inventors Ladder