What is the "Detector" ?
The Detector indicates with a blue light the presence of an electromagnetic field (inductive field), in particular at a frequency of 13.56 MHz, which is used by many contactless smartcards, in accordance with the international standard ISO 14443.
The Detector is typically used to check if a reader’s antenna is active or not. It may also be used to guess the field management by the reader (field always present or not, field strength, etc.).
If you do not work in this sector, the Detector may be just a slick gizmo to play with when you enter a transit network, or a puzzle for your friends.
For this purpose, the Detector is not selectively tuned to the radio frequency of 13.56 MHz, and therefore should not reduce much the working range of the contactless card.
Electromagnetism is one of the four fundamental natural forces (along with gravitation, and the “strong” and “weak” interactions).
Faraday established that, when varying the electrical current in a wire, another wire may recovered part of the electrical energy. This principle is used in many electrical equipments, such as transformers, electrical motors or FM radios.
The electrical energy may be used to transmit data (e.g. FM radio music) or energy (e.g. transformers).
With contactless smartcards, both energy and data are transmitted to the smartcard: the reader both powers the card electronics and exchange data with it.
For more information about the contactless smartcards, see for example the ISO 14443standard.
The manufacturing files are freely accessible to allow you to manufacture other Detectors if you wish.
The Detector antenna is adjusted to work with the other components of the Detector to emit a light as bright as possible.
The antenna has the shape of the logo of Spirtech. When Spirtech was founded, variations around the contactless cards antennas where searched for a pleasant logo.
In the Detector, to optimize performances, the logo is tripled to get an antenna with six turns.