Technalogix TAU-100, Manual

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VI-2
Interface Components
The interface section of the Series II-H PCB includes the front panel switch interfacing in addition to
the buzzer and carrier disable output circuits.
The (3) momentary switches found on the front panels of each enclosure are tied to the
microcontroller through an isolation stage to avoid any static discharge or noise on the switch
wiring from reaching the microcontroller. Optoisolators U5 and U6, in addition to components
R4…R15 create the necessary isolation to the sensitive microcontroller. By depressing any
momentary switch, a ground (0V) is applied to the input of the optoisolators. The optoisolators will,
in turn, output a ground (0V) to the microcontroller.
The membrane tactile switches found on the front panels of the enclosures operate in the following
manner with a depress:
POWER – When unit is plugged in, AC is supplied to the fan and switching power supply input,
but the amplifiers are still turned off. In order to turn the amplifiers on, wait ten seconds after
plugging the PA in and push in the “POWER” tactile button. The LCD will read “Soft Start Warm
Up, Please Wait”. After ten seconds the bias voltages will be turned on and you may then plug in
the RF drive. Depress for (1) second to turn on and (3) seconds to turn system off. In the case of
multiple enclosures, all POWER switches are tied together in each enclosure, so only one needs
to be depressed.
NAVIGATE –
Turns on backlight to LCD and displays forward and reflected RF power and DC
supply voltage parameters. When power amplifier is first turned on, the LCD comes on
automatically and this information is displayed. Information is displayed for approximately 2
minutes before the backlight turns off and the display is cleared. This is set up so as not to burn
any pixels into the LCD from extended on time. In the case of multiple enclosures, the NAVIGATE
switches are individual to each enclosure.
SELECT –
Turns on backlight to LCD and displays forward and reflected RF power and DC
supply voltage parameters. When power amplifier is first turned on, the LCD comes on
automatically and this information is displayed. Information is displayed for approximately 2
minutes before the backlight turns off and the display is cleared. This is set up so as not to burn
any pixels into the LCD from extended on time. In the case of multiple enclosures, the SELECT
switches are individual to each enclosure.
RESET –
Tactile pushbutton resets the monitor and control system. The amplifier gets shut down
for under 0.5 seconds and comes back on with each depress of the reset button. At the same
time, all fault counters in the microcontroller software are reset and the LCD is reset in the same
manner as it is with a depress of the NAVIGATE button. Reset switches are individual to each
enclosure but may be tied together externally through the remote port, as explained later in this
section.
The buzzer control comes from pin 5 on microcontroller U14. The control signal turns on the base
of transistor Q1, which allows current to flow through the single tone magnetic buzzer. Jumper J4