Since Edison’s day electrical meters have measured the flow of current in one direction only—from power plant to user. Customers can then be billed for the amount of electricity they use. Measuring current that flows in both directions requires a bi-directional or net meter like this one. It runs forward when the user draws power from the electric lines and backwards when solar panels make more power than the building is using. This feature can lower the customer’s monthly electric bill and reduces the need for new power plants to meet growing demand.
GE model P-3 alternating current portable ammeter in a wooden case. A laboratory ammeter with plastic panel, glass-covered mirrored scale, two binding posts, three-position rotary switch. Paper calibration sheet in lid, tested 19 May 1936. A small calibration sticker reads: "12-3-[19]81". Two scales: 1 to 10 amps, and 0.5 to 5.0 amps. Leather handle deteriorated and packed inside meter.
Cell Phones for Soldiers recycling mailer. Received by donor with a delivered package of books. Intended to promote recycling of cell phones by encouraging users to send in their old phones which would then be provided to active duty service personnel serving overseas.
An early radio practice set used as an introduction to radio technology and Morse code. Includes two send-receive stations, each with a key, buzzer, cat's whisker detector, and connectors for ground, aerial, battery and earphones. A Morse code chart is printed on each station. Includes two crystals and two single-piece earphones, four RT&S Co. #328 ceramic insulators, a roll of bare copper wire, and a roll of insulated wire. Penciled note: "Toy Mfgs. of U.S.A. #83"; printed on package: “A. C. Gilbert”, “4004-T Wireless Telegraph Outfit”. Original price $5.00
Helpline suicide prevention sign from the Mid-Hudson Bridge. This sign was mounted on the Mid-Hudson Bridge by the Dutchess County Department of Mental Hygiene as part of a program to dissuade people from committing suicide. The sign directed people in distress to one of two specially designed radio-telephones that put them in contact with a nurse at a local hospital who could intervene. (For one of the phones, see catalog #2009.0226.01).
A porcelain, surface mounted keyless lamp socket for a medium-screw based lamp. Molded on base: "G.E.Co. U.S.A. / Cat. 9402 / 660 W / 250 Volts". GE logo stamped on base contact. Hot contact has a spade terminal with stub of stranded wire.
Until the late 20th century telephones, computers and televisions operated in largely separate realms. Sometimes those realms intersected, as when computers or television signals were transmitted over telephone wires, but users generally operated separate, highly specialized devices for each. In the 1990s, however, these realms began to converge. This prototype PDQ-1900 smartphone shows the convergence of telephone and computer technologies in one unit. Cellular telephones entered the market in the 1980s and by late ‘90s many Americans owned one. At the same time small, handheld computers called personal digital assistants were also introduced by several makers. Palm Inc. made one popular line of PDAs and in 1999 Qualcomm combined the functions of a Palm PDA with a cell phone in this PDQ-1900 into a device that came to be known as a “smartphone.” Later, more powerful smartphones added a vast array of features–including the capability of receiving television programs erasing the lines that used to exist between these separate technologies.