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Ch. 6 Intensity Control - Coggle Diagram

- - - - SCR (silicon controlled rectifier)
        
        A heavy-duty power transistor.
      - SCR dimmer
        
        A dimmer that uses two SCRs in a back-to-back configuration to control the load circuit. A low-voltage control circuit uses the gating principle to switch the SCRs to a conducting state.
      - gating principle
        
        A rapid switching on and off of electrical power.
  - - - Separate and complete; in this case, pertaining to information represented by binary code.
    - - multiplex
        
        (1) To transmit two or more messages simultaneously on a single channel.
        (2) To carry out several functions simultaneously in an independent but related manner.
  - - - autotransformer
        
        A type of dimmer that increases or decreases lamp intensity by varying the voltage within the circuit.
      - Archaic Dimmers
        
        Although the dimmers described in this box are no longer installed in theatres, they do have historical significance in the progress of stage lighting.
      - Saltwater Dimmer
        
        The oldest type of dimmer was a frightening contraption. The primary component of this death trap was a bucket of salt water. Metal plates were attached to one leg of the circuit, and one of these plates was completely immersed in the bucket. The current passing through the circuit varied with the depth of immersion of the second plate.
      - Saturable Core Dimmer
        
        Another old dimmer worked by using a small DC current to magnetize an iron core. The AC load current passed through this iron core. As the level of magnetism was increased, the conductivity of the core also increased, and the lights connected to the dimmer came on.
      - Magnetic Amplifier Dimmer
        
        A more efficient version of the saturable core dimmer, the magnetic amplifier, was introduced in the 1950s but was soon relegated to obscurity by the development of the silicon controlled rectifier dimmer.
      - Thyratron Tube Dimmer
        
        The thyratron tube dimmer was the first electronically controlled dimmer, and the first to use the gating principle—a rapid switching on and off of the load current. However, thyratron vacuum tubes were large, had to warm up before they worked, didn’t last very long, and were somewhat expensive.
      - Resistance Dimmer
        
        The resistance dimmer functioned as a large variable-capacity resistor. When lights connected to it were turned off, it converted all the electrical energy flowing to it into heat. As it was turned on, its resistance decreased, and current reached the lamps.
- - - - The space on the audience side of the proscenium arch.
  - - - A device, usually electronic, that effects a gradual changeover from one circuit to another; in lighting it gradually changes the intensity of one or more dimmer circuits.
  - - - Non-permanence; in computers, a volatile memory will be lost if the computer loses its power supply.
    - - In the context of computers, refers to the hard disk becoming inoperable and the data stored on it non-retrievable.
  - - - Smaller Systems
        
        Memory for up to several hundred cues
        
        Capability of controlling up to 512 dimmers or other equipment
        
        Maximum of one video screen for displaying various system functions
        
        A timed fader
        
        Some type of group or submaster control
        
        Control of dimmer intensity by individual sliders
        
        Keypad for addressing memory and functions
        
        Limited backup system in case of main computer malfunction
      - Larger Systems
        
        Memory for approximately 1,000 or more cues
        
        Control of 1,000 or more addresses for dimmers or other equipment
        
        Expanded functions
        
        Two or more video screens displaying multiple functions simultaneously
        
        Advanced backup systems
        
        Sophisticated group or submastering
        
        More control functions to permit simultaneous cues at different fade rates
        
        Dimmer and other functions addressed through a keypad
        
        Remote keypad
        
        Hard-copy printer for printing data about the lighting design
        
        Self-diagnostic program to identify malfunctioning component in case of breakdown
        
        Moving light control software and encoders
        
        Networking capabilities, both wired and wireless
    - - A function of computer lighting consoles; used to virtually connect a channel to a dimmer; used for dimmer intensity control.
    - - The grouping of two or more channels under one controller.
    - - A gradual increase. In lighting, usually from darkness to a predetermined level of brightness. Synonymous with fade-up.
    - - A gradual decrease. In lighting, usually from a set level of brightness to darkness.
    - - A fade in which the fade-up and fade-out are accomplished at different rates or speeds.
    - - Refers to the time interval that the second part of a split time fade or subsequent cue follows the first. Also called a follow by some manufacturers.
    - - Refers to the time interval that the second part of a split time fade or subsequent cue follows the first. Also called a delay.