Specifications

Section 19. Troubleshooting

19-10

19.4.3.4 Adjusting Charging Circuit Voltage

Campbell Scientific recommends that only a qualified electronic technician

perform the following procedure.

Yes

Place a 5 kohm resistor between the charging regulator’s

12 V output and ground terminals. Use a voltmeter to

measure the voltage across the 5 kohm resistor. Connect a

charger that provides a voltage greater than 17 V to the

input of the charge circuit. Adjust pot R3 or A12

(depending on the board version) so that the voltage across

the 5 kohm resistor is 13.5 V. Can the output voltage be

set to 13.5 V?

NOTE: The board must be about 25ºC when setting the

output to 13.5 V.

Disconnect the charging source and remove the 5 kohm

resistor. Place a 50 ohm, 1 watt resistor between the

charging regulator's 12 V output and ground terminals.

Connect the charging source and use a voltmeter to

measure the voltage across the 50 ohm resistor. Is the

measured voltage between 13.0 and 13.5 V?

NOTE: After measuring the voltage, disconnect the

charging source. If the charging source is connected

for more than a few seconds, the resistor will get hot.

Send the charger to Campbell

Scientific for repair. Call for an

RMA number before returning the

charger.

The charger is functioning

properly. Testing and adjusting

charger circuit is now complete.