Modifications

C'est pour ces raisons qu'elles apparaissent souvent dans les jouets, gadgets et appareils. Elles sont souvent identifiés sous la dénomination CdS (parce qu'elles sont faites de Cadmium-Sulfite), LDR (pour ''Light Dependant Resistor'' ce qui signifie Résistance dépendant de la lumière et Photo-résistance/photorésistance.

C'est pour ces raisons qu'elles apparaissent souvent dans les jouets, gadgets et appareils. Elles sont souvent identifiés sous la dénomination CdS (parce qu'elles sont faites de Cadmium-Sulfite), LDR (pour ''Light Dependant Resistor'' ce qui signifie Résistance dépendant de la lumière et Photo-résistance/photorésistance.

Fondamentalement, les photorésistances sont des résistance dont la valeur résistive (en ohms Ω) change en fonction de la quantité de lumière qui atteind le capteur (la partie en serpentin sur le dessus). Elles sont abordables (bon marchés), existent sous de nombreux formats/tailles, disponibles sous de nombreuses spécifications (caractéristiques) '''mais sont très imprécises'''.

Photocells are sensors that allow you to detect light. They are small, inexpensive, low-power, easy to use and don't wear out. For that reason they often appear in toys, gadgets and appliances. Theys are are often referred to as CdS cells (they are made of Cadmium-Sulfide), light-dependent resistors (LDR), and photoresistors.

Photocells are basically a resistor that changes its resistive value (in ohms Ω) depending on how much light is shining onto the squiggly face. They are very low cost, easy to get in many sizes and specifications, but are very innacurate. Each photocell sensor will act a little differently than the other, even if they are from the same batch. The variations can be really large, 50% or higher! For this reason, they shouldn't be used to try to determine precise light levels in lux or millicandela. Instead, you can expect to only be able to determine basic light changes

Each photocell sensor will act a little differently than the other, even if they are from the same batch. The variations can be really large, 50% or higher! For this reason, they shouldn't be used to try to determine precise light levels in lux or millicandela. Instead, you can expect to only be able to determine basic light changes

For most light-sentsitive applications like "is it light or dark out", "is there something in front of the sensor (that would block light)", "is there something interrupting a laser beam" (break-beam sensors), or "which of multiple sensors has the most light hitting it", photocells can be a good choice!

For most light-sentsitive applications like "is it light or dark out", "is there something in front of the sensor (that would block light)", "is there something interrupting a laser beam" (break-beam sensors), or "which of multiple sensors has the most light hitting it", photocells can be a good choice!