Microtel Series 500 - Manual (Page 13)

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II.A.1 LCD Panel and Keyboard
The door of the inner chassis contains the system’s 20-key keyboard and the LCD
display panel. These circuit modules are connected to the System Bus via a 20
conductor flat cable.
II.A.2.
System Bus Assembly
Located in the upper section of the chassis is the System Bus. The Bus and card cage
contains printed circuit board connectors sockets for up to five circuit cards. Two of the
plug-in circuit card connectors are specifically designed to accept the CPU card (card
slot J1) and the Telephone Interface Card (card slot J5). The other three slot positions
(J2, J3, and J4) accept other system level circuit cards such as the Speech Synthesizer
card and the Speech Memory cards. The System Bus contains all circuitry necessary to
route audio and computer signals from card to card, and out to the I/O bus located in
the lower section of the System Chassis.
II.A.3.
Power Supply Card
Located to the left of the System Bus Card, and directly above the Battery well, the
Power Supply occupies the extreme left card position. The Power Supply Card does
not, however, plug directly into the System Bus Card. The Power Supply delivers power
to the entire system, and contains indicators for AC Power, +5 Volts Power, +12 Volts
Power, and Low Battery. Additionally, the Power Supply Board contains a three
position terminal strip for incoming AC power, a 1/2 Amp fuse, and the system power
switch.
II.A.4.
System Battery
The system battery is located to the left of the I/O bus card cage. The battery is a 12
volt, 7.0 ampere-hour battery, capable of powering the system through extended power
outages. The total battery backup time is dependent upon several factors, but it is
primarily related to the types of option cards installed in the system and the age of the
battery. The following matrix illustrates the typical battery lift for various combinations of
Digital and Analog Input Cards.