Emerson Liebert iCOM Training And Service Manual page 192

iCOM
Control Training and Service Manual
Impedance: Opposition that a circuit offers to the flow of current through it,
measured in Ohms
Input: An incoming information signal
Isolation: Separation of one device or environment from the effects of an
adjacent or connected device or environment
Lead Compressor: Compressor coming on first as a result of a call for
Cooling 1
Lag Compressor: Compressor coming on second as a result of a call for
Cooling 2
LED: Light Emitting Diode; a semiconductor that emits light when electric current
is passed through it by way of two terminals
Manual Override: A means of bypassing triac switches at all levels for manual
operation of system components for test or emergency
Memory: In a digital system, the part of the system where information is stored
Microprocessor: An Integrated Circuit (IC, or set of a few ICs) that can be
programmed with stored instructions to perform a wide variety of functions (A
microprocessor consists of at least a controller, some registers and some sort of
Arithmetic Logic Unit (ALU).
N-Type Semiconductor: Semiconductor crystal doped to have an excess of free
electrons with a predominately negative current carrying capacity (also referred to
as a P-Type Semiconductor).
Off Time: The time since humidification was last on
Output: An outgoing information signal
P-N-Junction: Interface boundary between two semiconductor regions with
differing electrical properties (Current only flows across the junction in the forward
direction if circuit voltage exceeds a certain threshold. Current cannot flow across
the junction in the reverse direction.)
P-Type Semiconductor: Semiconductor crystal doped for an excess of holes to
enable heavier positive current-carrying capacity (also referred to as an N-Type
Semiconductor).
PCB: Printed Circuit Board; made of insulating material with conducting paths
secured to one or both sides
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