38
FORM 160.54-M1
ISSUE DATE: 10/25/2019
SECTION 3 - MICROBOARD 031-01730-000
JCI COMPANY CONFIDENTIAL
JOHNSON CONTROLS
The Lamp Dimmer is an integrated circuit that is the
electrical equivalent of a 10K ohm potentiometer with
The Lamp Dimmer controls the position of the potenti-
ometer. The Lamp Dimmer varies the brightness of the
backlight by applying a variable voltage (0 to 5.0 VDC)
or a variable resistance (0 to 10K ohms) to the Backlight
Inverter Board. If Program Jumpers JP7 and JP8 are in-
stalled, the Lamp Dimmer output is a variable voltage;
if both are removed, the output is a variable resistance.
The Lamp Dimmer outputs Brightness Control Wiper
(J6-7) to the Backlight Inverter Board. If configured for
variable voltage output, the voltage between J6-7 and
J6-8 can be varied from 0 VDC (100% brightness) to 5.0
VDC (0% brightness). If configured for variable resis-
tance, the resistance between J6-6 and J6-7 varies from
0 ohms (0% brightness) to 10K ohms (100% brightness).
See
SECTION 7 - LIQUID CRYSTAL DISPLAY
,
TION 8 - DISPLAY INTERFACE BOARD
, and
TION 9 - DISPLAY BACKLIGHT INVERTER BOARD
of this manual for details of the display interface.
Remote Setpoints
Remote Leaving Chilled Liquid Temperature and Cur-
rent Limit setpoints can be input via the RS-232 E-Link
Gateway interface at J2 or directly to the microboard at
J22 (See
). The inputs at J22
are configured with Program Jumpers JP23 and JP24
to accept these inputs in either 0 to 10 VDC, 2 to 10
VDC, 0 to 20mA or 4 to 20mA form. See
for configurations and
of this manual for details of the
Remote setpoints.
POWER SUPPLY
The microboard receives 3 supply voltages (Microboard
J1) from the
Power Supply
; +12 VDC, -12 VDC, +5
VDC and ground. The -12 VDC and +12 VDC are used
directly by various circuits. The +12 VDC and +5 VDC
are input to
Voltage Regulators
to derive other regu-
lated voltages. The +5 VDC (fused by 5 Amp fuse F1
on rev E (and later) boards) is input to a +3.3 VDC
regulator. The output is a 3.3 VDC regulated voltage.
The +12 VDC, fused by 5 Amp fuse F2 on rev E (and
later) boards, is input to a 5 VDC regulator. The out-
put of this regulator powers only the Analog circuits.
This includes the MUX, A/D converter, CM-2 module,
Mod A Solid State Starter Logic Board, Transducers
and thermistors. As depicted on the microboard fig-
ure, these voltages can be monitored at Test Posts TP1
through TP6.
SERVICE REPLACEMENT
Replacement part number 331-02430-601 is supplied
as service replacement for Microboard 031-01730-
SECTION 4 - MICROBOARD 031-02430-
Renewal
Parts – OptiView Control Center (Form 160.54-RP1)
.
Replacement part 331-01730-601 (Microboard 031-
01730-000) is no longer available.