TH2883 Series Operation Manual Chapter 9 Handler interface
9-5
Figure 9-2 Simplified diagram of the input signal
In figure 9-2, the default jumper setting is to use external voltage source. Actually, the input signals
and the output signals use the external voltage source together. The Current-limit resistor is used to
limit the current and the default resistor is only suitable for external voltage source range from 5V
to 8V. If the external voltage source is higher than 8V, you should replace the Current–limit resistor
to avoid damaging circuit components. Current-limit resistor R705 and R706 should be both
replaced. The detailed replacement information about Current-limit resistor is listed in table 9-2.
Current-limit resistor
Range of external voltage source
680Ω
5V to 8V
1.2KΩ
8V to 15V
2.2KΩ
15V to 24V
Table 9-2 Current-limit resistor for different voltage
9.3
Jumper setup on HANDLER interface
There are two jumpers on the Handler interface board. The two jumpers are used to select the
internal voltage source for external voltage source for the output signal and input signal. Their
locations are shown in figure 9-3.
