Tektronix TAS 465, Руководство по обслуживанию

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3Ć8
frontĆpanel processor converts the LED identification received from the host
processor to the correct LED address on the latch (U202) and changes the
state ofthe LED.
Switches A4
4
The frontĆpanel switches and menu switches are arranged in an array of 9
rows and 8 columns. The switch scanner sets the nine row lines low in
sequence and performs an eight column scan to check for any changes in
state and reports these changes to the host processor. When a switch is
closed, one row is connected to one column line through an isolation diode
and the column line is pulled low indicating a switch closure.
The power supply is a switching power converter. It supplies power to all
oscilloscope circuitry.
Two generations ofpower supplies were produced. The early version reĆ
quired the operator to configure it to the incoming line voltage; the later
version automatically adjusts to the incoming line voltage and has no exterĆ
nal adjustments. This service manual documents the power supply beginĆ
ning with the introduction ofthe new version.
The switch, located on the front panel, controls all power to the
oscilloscope including the power supply.
The fan provides forced air cooling for the oscilloscope. It connects to +12ĂV
on the A63 Power Supply board.