Kantronics KPC–3 Plus User Manual page 35

Caution: Do not exceed the power specifications for the KPC-3 Plus (see
specifications).
If you elect to install a fuse in the positive lead, do not use a fuse of greater than 200-
250 mA.
External Power Transformed from 120-V ac Mains
You can use external power from a 120-V ac power source after transforming the
external power to 12 V dc (using a class 2 transformer: input 120 V ac 60 Hz 6 W;
nominal output 12 V dc 300 mA).
The steps are:
Step 1. You may order from Kantronics, as an option, a Kantronics 120-V ac to 12-V
dc 300-mA power adapter, or you may purchase the needed 120-V ac to 12-V
dc 300-mA power adapter from a third party,
Step 2. Connect the 2.1-mm connector on the assembly to the power connector of
the KPC-3 Plus and plug the power adapter into the 120-V ac power source
(being sure that the center is positive),
Step 3. Press the power switch on the front panel of the KPC-3 Plus to turn your
KPC-3 Plus ON, confirm that the power indicator next to the power switch
goes on, and then press the power switch again to turn the power OFF.
If the power indicator (LED) does not go on as expected, the unit may be defective,
so you should check with your dealer.
Internal Power, from a Battery.
For activities such as field day and back-packing, you can also install an internal 9-V
battery for power, after installing a battery clip on the printed circuit board of the KPC-3
Plus.
Note: Before installing a 9 V battery inside the KPC-3 Plus, you need to install a battery
clip (pigtail) and configure jumpers J1 and J2. First, purchase a 9-V battery clip (e.g.,
Radio Shack's heavy-duty 9-V snap connector, part number 270-324). Second, solder
the clip leads to the battery pads on the printed circuit board (PCB). The pads are
labeled ―+BATT-‖ and are located in the corner of the PCB near the power connector.
Make sure you solder the positive lead of the battery clip to the ―+‖ pad, and be careful
not to damage any other connections on the PCB (use a low watt iron). Third, set
jumpers J1 and J2; defaults are J1 OFF (jumper on one leg only) and J2 ON (jumper on
both legs). In this position, the battery will power the TNC and will be cut off (by jack P3)
if an external power supply is attached. If you desire the battery to take over, i.e. run the
unit, in case the external power supply is plugged in but fails (or not turned on), then set
J1 ON and J2 OFF. In this configuration, whichever supply has the higher voltage
(battery or external supply) will power the TNC.
To use a 9-V battery for power, install the battery as follows:
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