JP3: Relay Driving Power Source Selection
It is necessary to provide +5 V as the relay channels driving power
source. And the power source can be selected as internal or external by
JP3.
The default setting of JP3 is an internal power source, which means +5V
is provided from the PC. However, you can also select an external power
source by shorting pin2 and pin3 of JP3.
The external power source is provided through TB7. Since there is a
transformer on the circuit, the voltage range of external power should be
within DC +7V ~ +30V.
Jumper Setting
Description
Internal power source
(Default setting)
13
JP3
External power source
Chapter 2