Air-Cooled Rheostat, Model E Foodsafe the microfarad-bridge decade for RC-time-constant

the microfarad-bridge decade for RC-time-constant work and audio-frequency timing circuits

5m optical bench

Pink-dotted ends and steel keepers across this 50 x 12mm Alnico cylinder pair simplify pole identification while the keepers preserve field strength during cardboard-box storage

this resistor module on a demonstration base with 4mm plug connections drops into series with bulbs and LEDs in student circuits

phase separation

Air-Cooled Rheostat, Model E Foodsafe the microfarad-bridge decade for RC-time-constantUsed to dissipate heat during sustained high current work, this air cooled rheostat carries a slide bar carriage on a vitreous enameled tube for variable resistance under thermal load.