The ballast is a fixed resistor with usually two center taps, and the fan speed selector switch is used to bypass portions of the ballast : all of them for full speed, and none for the low speed setting.
12.
Produced by the German Loewe-Audion GmbH as far back as 1926, the device consisted of 3 triode valves ( tubes ) in a single glass envelope together with two fixed capacitors and four fixed resistors required to make a complete radio receiver.
13.
Beside Thailand, Singapore has been selected as the production source for some other components, including fixed resistors, coils, speakers, remote control units, power supplies and AC adaptors, and Malaysia for aluminium electrolytic capacitors, switches, tuners, potentiometers, thick film chip resistors, and ceramic disc capacitors.
