Tek-Trol Tek-LCD 7802A, Instruction Manual, Page: 13 / 43

Figure 1. Connector Board
3.1 Input Signal & Backlight Connections
Signal and backlight connections are made to a four-terminal connector mounted in the base of the
enclosure. For installations without backlight, only the two signal terminals are connected. The 4-20
mA input with no backlight has a maximum voltage drop of 3 V and is wired as shown in Figure 2.
The loop-powered backlight configuration requires a total maximum voltage drop of 6 V. The
backlight is recommended for dim lighting conditions and is enabled when wired as shown in Figure
3 or Figure 4.
Figure 2. Input Connections without Backlight