SmithsonianMag has a short piece on the history of the pay phone, which went from a massive communication innovation to a physical reminder of a pre-cellular age in hardly any time at all:
Gray’s first prototype device involved a box that covered the mouth of the receiver and would slide away when a coin was deposited. However, it was rejected on the grounds that one coin could buy several phone calls and that if another station was called, the receiver would also have to pay – obviously not an ideal solution. After a few more failed attempts, Gray found the suprisingly simple solution: a “coin-controlled apparatus” that used a small bell to signify the operator when a coin was deposited (US 408,709), and, a couple years later, a more elaborate “signal device for telephone pay stations” (US 454,470).
Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground” – Adafruit’s Apps!
Maker Business — Alibaba to invest $15b in tech, set up research labs around the world
Wearables — Hand beading mimicry
Electronics — Trigger happy oscilloscope?
Biohacking — Biohacking: Visioneer – AI Glasses to Assist the Visually Impaired
No comments yet.
Sorry, the comment form is closed at this time.