Specifications subject to change without notice
© Digital View Ltd – Doc Ver 1.7: 23 April, 2014 (SGX-1920_manual.doc)
Page
28 of 70
Design Guideline for making VR circuitry :
CNB1 – Backlight inverter connector: JST B5B-XH-A (Matching type : XHP-5)
PIN SYMBOL
DESCRIPTION
1 GND
Ground
2
VBKL
+12V/24VDC, backlight power supply
3
BLCTRL
On/Off control (enable) – see JB2 & JB3
4
BVR_WIP
Brightness VR - WIP
5
BVR_A
Brightness VR A
CNC1 – Control switch, JST B12B-XH-A (Matching type : XHP-12)
PIN SYMBOL
DESCRIPTION
1
PSWIN
Power button A
2
SW_ON
Power button B
3
BVR_A
Backlight Brightness VR pin A
4
BVR_WIP
Backlight Brightness R pin WIP
5
BVR_B
Backlight Brightness VR pin B (470 ohm resistor to +5V Vcc)
6 GND
Ground
7
MENU
OSD menu
8 -/LEFT
OSD
-/Left
9 +/RIGHT
OSD
+/Right
10
SEL_DN
OSD Select down
11
SEL_UP
OSD Select up
12 NC
No
connection
The VR for brightness depends on the inverter. The main power load for On/Off is handled by a relay on the controller.
Example for circuit design :
Signal description / Notes :
1) R1 : 470ohm on board
2) RPOT is an external potentiometer (in-line dip
style) that can be plugged directly into CNC1 pins
3,4,5. RPOT must be supplied / installed by user.
3) BVR_B : Voltage tapped from “top” of
potentiometer, the node of R1 and RPOT.
4) BVR_WIP : Voltage tapped from wiper arm of
RPOT.
5) BVR_A : Voltage tapped from “bottom” of
RPOT.
Note : BVR_A voltage is left floating on the
controller board. To use this circuit, you need
to tie this point to a potential (usually GND,
available at CNC1 pin 6).
1.)Choose RPOT = 10K
2.) Tie BVR_A to GND
3.) Circuit analysis gives BVR_WIP as the
following (see Figure 1)
BVR_WIP = 5 x (Rbc/10.47)
where BVR_WIP is in Volts.
And Rbc is the resistance from the wiper arm
to bottom of pot in Kohms.
To evaluate, plug in different values of Rbc :
Rbc BVR_WIP
0
0 V
2.5 K
1.2 V
5 K
2.4 V
7.5 K
3.6 V
10 K
4.8 V
So this circuit could provide Brightness
adjust voltage ranging from 0V to 5V.
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from