Projector

Information and news by means of film has been strongly promoted in Yugoslavia right after the WW2, and people were building cinema theaters everywhere. The ISKRA* company (Kranj, Slovenia) was charged with the development of cinema projectors and other inclusive tech, such as cinema sound systems.

So the first almost-copy of Ernemann 7B cinema projector, the NP-1, was made owing to the fact that, post-war, all German patents were annulled. This model was soon followed by the NP-21 (shown here).

The NP-21 was not so much a copy, save its shape, as the ISKRA engineers have implemented certain new solutions to make it functionally better.
Between 1952 and 1966 about 3000 of those projectors have been built and sold all over the World. Some are still in use.

The 35mm film projectors of those days used a carbon arc lightsource known for intensity of both light and heat, so the celluloid film strips were always at risk of bursting into flames if the projection speed (of 24 fps) was impeded even for a few seconds.

Thus the largest part of problem solving was related to high operational temperature removal, and to precise, dependable film transport. Much later, the easily flammable cellulose nitrate film base was replaced with cellulose acetate, and then polyester.

The troubles our fathers had with this "video of yore"!

Today we grumble about our camera processors warming up, while some of our projectors easily fit in the coat pocket!

Tech is fun!
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* ISKRA means "spark" in many Slavic languages.
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