Constant Voltage
What are the standard voltages used for this type of system
25V, 70V, 100V
What causes the voice coil of a speaker to move (making sound waves)
Electro magnet constantly changing polarity as the SINE wave changes from +/ -
How does energy transfer between the two coils in a transformer
Electromagnetic induction (no physical contact)
What letter represents impedance?
Z
This circuit contains addressable devices
SLC - Signaling Line Circuit
Which value voltage is best for long cable runs due to low power loss?
70V
Permanent magnet
voice coil (inductor)
Cone
Self amplified speakers have what located at each speaker?
An amplifier
What is impedance measured in?
Ohms
An off normal condition of a suppression system causes what signal at the FACP?
Supervisory
What component is found at the back of each speaker?
Transformer (XFMR)
What causes the magnetic field around a coil to change intensity?
AC Wave increasing/decreasing
With _________ _________ speakers impedance matching is critical
direct wired
Impedance is made up of the vector sum of which 2 values?
Resistance and Reactance
This circuit has contact closure devices & uses EOL resistors to determine circuit condition
IDC - Initiating Device Circuit
In a 70V paging system, which type of transformer is used at each speaker to make the signal appropriate for a low impedance load?
Step down XFMR
two 8 ohm speakers wired in parallel gives a total impendence of what?
4 ohms (parallel divides value/quantity)
The standard frequency Amps and Speakers are rated at is:
1KHz
A speakers impedance changes with a change in?
Frequency
The devices on this circuit are output only
NAC - Notification Appliance Circuit
What output would you use at the amplifier to wire a constant voltage system?
70V (positive)
Com (negative)
What out put would you wire a direct 8ohm speaker to on a an amplifier?
8 ohm (impedance must match) (high quality low Z speakers)
To combine sound waves improving sound quality and volume wire your speakers to be
in phase
If the frequency of a signal is increased impedance will?
increase (directly proportional)
How many seconds does a trouble signal have to report to the FACP
Up to 200 seconds