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Examples of the early generation of control in
California. The 911 controller used "pins" to program
the timing intervals. By placing a pin in the different timing
multiples (i.e. 1,2,4,8,16,32) on could program the various
parameters to the nearest second or tenth of a second. The
disadvantage of this type was that after a time the pin contacts
would get "oxidized" and throw some timings off!
The other great feature that these controllers had was use of a representative "signal" for each timing ring to show the status of the phase. Pictured here is the eight phase dual ring version.
Here is the newer version of the 911, called the 820. It has a menu driven display and all parameters are keyboard programmable. The special feature of this controller is an actual LCD graphic display of the intersection- complete with cars and crosswalk lines! This controller, along with the newer 820A version of this controller is the most popular kind used here in Southern California.
And here is the OSAM 820A...the ultimate in traffic controllers! Besides the new illuminated graphic display, its menu's are far more flexible and settings are much more customizable than the 820. These controllers are one of the most common in cabinets around Southern California Today.
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