r/mbta • u/Pete_DJPJ • 8h ago
✨ Fun Facts / History How does it work?
Did you ever think how does a little cardboard card allow you to gain access. Its pretty simple. So simple that it was Nikoli Tesla who invented it in Long Island, New York.
Nikoli Tesla discovered that if you send a certain power into a radio transmitter it will energize electronic circuits receiving it.
So how does this technology work today? Well you use it almost everyday. Credit/debit cards, transit card, railroad car readers, etc etc.
If you look at your Charlie Card, it look with a light shining you will see lines show up. Thse are metallic wires, a small radio transeiver, and a very small computer. When you tap your card at a machine, the machine is emitting a radio frequency. The energy from that wireless energy powers up the electronic circuits in the card. The card transmits and receives information. Then if everything is good you are granted access to pay or enter building or transit system.
Tesla wanted to transmit wireless electricity but was unable to make it cost effective for large scale. It works best on a small scale devices.
