Willis Lamm's Traffic Signal Collection (And Street Lights Too) Clicking on a picture will bring up a larger view in a new window.   Pittsburgh Transformer Co. Type A Street Light

One of the most unusual antique street lamps in the collection is this Pittsburgh Transformer Company "Type A" series fixture with a 20-inch smooth oval reflector. Aside from the cobalt blue color, what was most unusual was its circuit design. Instead of using constant current regulators, the Pittsburgh Transformer Co. systems used a constant current transformer and line current was regulated in each lamp fixture. This concept is more fully explained in the accompanying feature, Pittsburgh Transformer Company, and employed technological ideas that appeared around 1920. The Pittsburgh Transformer Co. primarily built and sold municipal and industrial transformers so their street light line was very basic, with one head design being generally marketed that came with three reflector and one globe options. This system was primarily marketed as a replacement for arc lamp systems.

Profile view. Cast head (casting No. 442) with ceramic bushings.

Underside view and lamp. Testing the lamp's operation.

Pittsburgh Transformer Co. used a tin glass process instead of porcelain enamel.

Back in service, around 100 years old.

Night lighting.

Click the image below to go to a detailed discussion on the Pittsburgh Transformer Co. system.
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