Feel free to use these designs/theories in your own stories and characters

Lycanthropy can have two forms, the most common being werewolves who have a default state of being human and turn into a savage wolf-monster under the light of a full moon.

Traditionally, solar amulets are made from Solite, which is a material that is painstakingly collected from the surface of the sun, which is brought into the proximity of a standard mana crystal during a Summer Solstice.
Solar amulets have been made in this way from the dark ages up unto the 1980s.

In 1981, Dr. Marvin Kees, a werewolf himself, was doing unrelated experiments in an environment that had no connection to a city electrical grid, and relied on solar power for electricity. He noticed that even under a full moon, he would not transform if he stood under an electric light that was being powered by this system.
He did several other experiments and discovered that photovoltaic cells specifically will absorb the sun's magical energy and allow it to be stored as electrical energy in a battery, later to be reproduced by electronic lights. A retail device quickly went into production to replace the often cost prohibitive solar amulets made from Solite.

1981 - 1989: Solar amulets consisted of a small photovoltaic cell, a Ni-Cd battery, a photoresistor, and an incandescent light bulb. Average run time was about 8 hours even after charging the device under full sunlight for days, often just barely enough for winter nights.

1989-2005: Solar amulets consisted of a polycrystalline photovoltaic cell, a NiMH battery, a phototransistor and an LED. From 1989-2000, this was usually a red LED but after 2000 these were often replaced with blue LEDs. Blue LEDs could be run at a lower intensity for the same effect and lasted longer.

2005-present: Solar amulets today consist of a monocrystaline photovoltaic cell, a lithium based battery (often lithium-iron-phosphate or lithium-cobalt), a small controller circuit, and a white LED. The lithium battery and white wavelengths make these newest solar amulets last the longest and have the strongest effects.

These devices have a power switch that disables both lighting and charging circuits, as it is vitally important that the device be charged from natural sunlight or lights powered by solar energy in order to have any effect.

Werewolves often have a pack mentality and live in close communities. Since photovoltaic panels can be used in this way, werewolf communities often have a high demand for solar power such that all of the lights in their homes and on the streets give off the sun's magical energy.

Electronic solar amulets can be purchased from your favorite amulet maker's catalog or website, usually for around $15. Traditional Solite amulets can be pruchased from only a few amulet makers and are often hundreds of dollars