AEG (Allgemeine Elektricitäts-Gesellschaft). Model A, c. 1900.
Voltage: 110 V; current: 1 A.
Globe: 110 mm diameter.
The helix is the heater; the thin rod in the center of the helix is the glower.
The plate with the three connectors (top) is labeled "AEGMA". It is marked in pencil with the date "24/10/07" (1907-10-24).
Thin connector: minus (-); thick connector: plus (+).
In the center there is a socket for the ballast (iron hydrogen resistor).
At the bottom there is a solenoid which turns off the heater when the glower becomes conductive.
On the side the plate is labeled: "1 A" (current).
Four thin iron filaments in an atmosphere of hydrogen gas. The resistance of iron increases with temperature (PTC, positive temperature coefficient), in particular at high temperature when the wire is glowing in red color.
Labelled: "1 A. 20 V." (current and voltage)
Resistance: c. 8 ohm at room temperature.
"D.R.P." (Deutsches Reichs-Patent)
"AEG" (Allgemeine Elektricitäts-Gesellschaft)
"1502"
Nernst-Lampe
Sparsamste elektrische Glühlampe für alle gebräuchlichen Spannungen.
Allgemeine Elektricitäts-Gesellschaft, Berlin
Most economical electric incandescent lamp for all common voltages.
Size 85 × 66 mm
Appeared in the German magazine Die Woche 1905