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Figure A-4. Calculating Value of Series Dropping Resistor
Remote Resistance Programming
Check switches A1 and A2 on the rear panel, they must be in their correct positions for CV and CC resistance/voltage
programming (See Figure A-2). A resistance variable from 0 to 4K ohms can be used to program the output voltage or
current from 0 to full scale. To program the output voltage, connect the variable resistance between J3-25 (CV RES/VOLT
PROG.) and J3-22 (E COM.). To program the output current, connect the variable resistance from J3-24 (CC RES/VOLT
PROG.) to J3-22 (E COM.).
If the programming lines become open circuited during resistance programming (user’s system becomes
disconnected from J3), the power supply's output will tend to rise above rating. The supply will not be
damaged if this occurs, but the user's load may be damaged. To protect the load, be sure that the
overvoltage trip point is properly adjusted. The unit includes clamp circuits to prevent it from supplying
more than about 120% of rated output voltage or current when the remote programming voltage is
greater than 5Vdc or remote programming resistance is greater than 4K ohm. Do not intentionally
operate the unit above 100% rated output. Limit your programming voltage to 5Vdc and programming
resistance to 4K ohm to assure reliable operation.
Remote Voltage Programming (Figure A-6). Check switches Al and A2 on the rear panel, they must be in the correct
positions for CV and CC resistance/ voltage programming (See Figure A-2). A voltage source variable from 0 to 5 volts,
can be used to program the output voltage or current from 0 to full scale. The load on the programming source is less than
1mA. To program voltage, the voltage source should be connected from J3-25 (CV RES & VOLT PROG) to J3-22 (E
COM). To program current, the voltage source should be connected from J3-24 (CC RES & VOLT PROG) to J3-22 (E.
COMMON). If the programming lines become open circuited (user's system becomes disconnected from J3) during voltage
programming, the Programming Protection circuit will reduce the power supply output to zero.
