What is it? #1988

[derekleffew]

Is it a dimmer(s)?





Pictures taken (not by me, I found them on the web) backstage in 1988.

 

[silicsound]

It looks like a rheostat or some sort resistance dimmer with selectable resistances. Whatever it is, I wouldn't want to be the guy operating it.

 

[cpf]

It's automated, though!

 

[65535]

Looks like a stepped attenuator, very large though if it is.

I've never seen a stepped rheostat, I thought by nature they were designed very relatively fine power control.

 

[silicsound]

I've never seen a stepped rheostat, I thought by nature they were designed very relatively fine power control.

They used stepped rheostats for starting large brushed DC motors a long time ago. To prevent the motor from drawing to much current and causing brownouts when it started up, now we use motor controllers to do the same thing.
They used a stepped rheostat because it was cheaper and they did not need fine control.

 

[DrPinto]

They used stepped rheostats for starting large brushed DC motors a long time ago. To prevent the motor from drawing to much current and causing brownouts when it started up, now we use motor controllers to do the same thing.
They used a stepped rheostat because it was cheaper and they did not need fine control.

Sounds right. Must be for those big old DC motors they used to rotate stages back when theaters were on DC. Interesting post on how a DC motor resistance box starter works here...

PWM Controller for giant antique 20+ HP DC motors? - All About Circuits Forum

 

[65535]

Cool I don't know a lot about motor controllers and starters historically. Make sense though, the picture seems to indicate a device shown in drawings and by description with a electromagnetic latch under power which releases to open circuit upon loss of power.

 

[bitbrat]

Hi guys,

Thanks for bringing this to my attention Derek. I work in this venue (which was heavily renovated shortly after these pictures were taken) - it is now known as the Victoria Theater, in Dayton, Ohio (The renovation was completed back in the 80's)

I started asking around some of the older hands that I know worked there way back when - brought back some memories.

The previous posters are absolutely correct, that is a DC motor controller, and it is actually for the caged motor visible in one of the other pictures driving a large belt. The belt was about 50' long and drove air handlers that served the auditorium.

In another picture you can see a cut-in in a wall full of breaker panels etc. This is where the old knife switch panel used to be (think Frankenstein type switches) and in the picture there is a blue rack of TTI dimmers and a black rack of Spectrum dimmers. Both of those racks still exist, and are in the back of our rental shop.

Anyway, the pictures were fascinating.

Andy Welch

 

[derekleffew]

The other pictures, to which bitbrat refers, are at CinemaTour - Cinemas Around the World - Victoria Theatre, Dayton OH .

In the 1960s, I spent many Saturday afternoons in this theater watching Disney movies; and later, plays and concerts, but was never backstage.

See also Victoria Theatre in Dayton, OH - Cinema Treasures and Victoria Theatre | Victoria Theatre Association .

 

[BGW]

Wow, that's really cool, thanks for sharing. Really neat to see that. I wonder if there are any theaters still around that have original equipment like that? I wish I would've been alive back then- it would be something else to see that in person.