A decrease drive is a mechanical planetary gearbox gadget to shift rotational quickness. A planetary reduction drive is a little scale edition using ball bearings within an epicyclic arrangement rather than toothed gears.
Reduction drives are used in engines of all kinds to increase the quantity of torque per revolution of a shaft: the gearbox of any car is a ubiquitous exemplory case of a decrease drive. Common household uses are washing machines, meals blenders and window-winders. Decrease drives are also used to diminish the rotational quickness of an input shaft to a 
proper output speed. Reduction drives could be a gear train style or belt driven.
Planetary reduction drives are usually attached between your shaft of the variable capacitor and the tuning knob of any radio, to allow good adjustments of the tuning capacitor with smooth movements of the knob. Planetary drives are used in this situation in order to avoid “backlash”, making tuning simpler. If the capacitor drive offers backlash, when one attempts to tune in a station, the tuning knob will feel sloppy and it will be hard to execute small adjustments. Gear-drives could be made to haven’t any backlash through the use of split gears and springtime tension however the shaft bearings need to be very precise.