Section 10.  Troubleshooting 
 
 
10.9.3.4 Adjusting Charging Voltage 
Note Campbell Scientific recommends that a qualified electronic 
technician perform the following procedure. 
The procedure outlined in this flow chart tests and adjusts PS100 and CH100 
charging regulators.    If a need for repair or calibration is indicated after following 
the procedure, see Assistance
 (p. 5) for information on sending items to Campbell 
Scientific. 
 
 
Adjusting Charging Circuit 
1) Place a 5 kΩ resistor between a 
12V terminal and a G (ground) ground terminal 
on the charging regulator. Use a voltmeter to measure the voltage across the 5 kΩ 
resistor. 
2) Connect a power source that supplies a voltage >17 V to the input 
CHG terminals 
of the charging regulator. 
3) Adjust pot R3 (see FIGURE: Potentiometer R3 on PS100 and CH100 Charging 
Regulators (p. 483) ) so that voltage across the 5 kΩ resistor is 13.3 Vdc. 
Can the output voltage be set to 13.3 V? 
     
     
No 
   
     
     
 
Yes 
     
50 Ω Load Test 
1) Switch the power switch to 
OFF. 
2) Disconnect the power source (transformer / solar panel). 
3) Remove the 5 kΩ resistor 
4) Place a 50 Ω, 1 W resistor between a 
12V terminal and a G (ground) terminal on 
the charging regulator. 
5) Reconnect the power source and then switch the power switch to ON. 
7) Measure the voltage across the ends of the resistor. 
Is the voltage 13.0 to 14.0 Vdc (13.3 if circuit just adjusted)? 
8) Switch the power switch to 
OFF. 
NOTE The resistor will get HOT in just a few seconds. After measuring the voltage, 
switch the power switch to 
OFF and allow the resistor to cool before removing it. 
 
Get Repair Authorization 
The charging regulator is damaged and should be repaired 
or replaced. 
 
No 
 
     
     
     
     
     
 
Yes 
     
Test Completed 
The charger is functioning properly. Remove the 50 Ω resistor.