LightKeeper Pro is a tool to aid in the repair of miniature incandescent light sets. Three distinctive methods are used to repair light sets: Quick Fix Trigger, Voltage Detector, and/or Bulb & Fuse Tester. The LightKeeper Pro sends a pulse of energy into a failed light set to bypass failed bulb shunts to illuminate the remaining bulbs of the set.
A red handgun shaped product invented in 2000 and first brought to market in 2001 as the LightKeeper. The initial concept repaired light sets in two steps. Both the initial product and the LightKeeper Pro repair the non-functioning shunt, located at the base of an incandescent light bulb.
A tungsten filament is located above the shunt in the lamp and illuminates when current flows through the bulb properly. The tungsten can fail for any number of reasons, due primarily to its fragility and limited life. The copper posts in the lamp base support both the filament and the shunt and have an oxide coating that serves several purposes. One of these purposes is to keep the shunt, which is aluminum, from engaging prematurely. When the shunt is engaged, the tungsten filament is permanently disabled. Conversely, upon failure of the filament, the shunt is designed to become welded to the copper posts due to high voltage (AC mains). When working as designed, the shunt will then carry the current, leaving the failed bulb non-illuminated – while other bulbs remain lit. The non-illuminated bulb should be replaced as soon as practical to prevent an unnecessary burden on the remainder of the lit bulbs (See [1].) 4 burned out bulbs in a 50 light set decreases the remaining life of the 46 lit bulbs by 63%. The LightKeeper Pro, introduced in 2004, repairs most miniature incandescent light sets in one step. It sends a pulse of energy into a failed light set by simply removing one bulb, inserting the LightKeeper Pro’s socket connector into that empty socket – and pulling the quick fix trigger. The trigger initiates a spring activated, piezoelectric device to create the additional energy needed to break down the oxide coating. A shunt repaired by the LightKeeper Pro will then allow the light set to glow by applying partial line voltage supplied via a diode chain in the LightKeeper Pro. The repair of the light set is permanent, but the failed bulb should be replaced. By inserting the initial bulb back into its socket, the functionality of the light set is restored.
A broken wire, loose or missing bulb, for example, cannot be repaired by the Quick Fix trigger. An audible voltage detector is included in the LightKeeper Pro to allow the user to identify the location of those faults. Also included are a bulb & fuse tester, bulb removal device and a storage organizer in the handle.[2]