CC Operation

Programming for CC operation is straightforward. Program each output to the desired voltage limit point. Then program each output to supply half of the total desired operating current. Both outputs will operate in CC mode. Note that the total desired current cannot exceed the combined current capability of both outputs. Figures 4-11 and 4-12 are examples of parallel configurations. These configurations apply to both CV and CC operating modes. Note the sense lead connections.

10 ASSIGN @Ps TO 705

20 INPUT "ENTER VOLTAGE LIMIT'',V

30 INPUT "ENTER OPERATING CURRENT",Oc

40 C = Oc/2

50 OUTPUT @Ps;"CLR;VSET1,'';V;";ISET1,";C;";VSET2,";V;";ISET2,";C

60 END

LINE 10: Assigns the I/O pathname to the power supply.

LINE 20,30: Enter the voltage limit and operating current.

LINE 40: Divides the total current requirement by 2.

LINE 50: Clears the supply and sets each output to supply half of the desired operating current at any voltage up to the desired voltage limit.

CV Operation

For CV operation, one output must operate in CC mode and the other output must operate in CV mode. The output that is operating in CV mode will be controlling the voltage regulation of both outputs.

In the example that follows, outputs 1 and 2 (both 40 W or 80 W Low V channels) will be operating in parallel with output 1 in CV mode and output 2 in CC mode at output voltages above 2.5 V. Each is programmed to one half of the desired current limit point. Above 2.5 V, the voltage for output 2 is always programmed higher than that of output 1 to ensure that output 2 operates in the CC mode. Note that any current from output 2 that is not required by the load flows into the downprogrammer of output 1 and is reflected in the current readback of output 1. The total current supplied to the load can be read back by adding the results of reading back the currents of outputs 1 and 2. At 2.5 V and below, the outputs are set to the same voltage and the operating modes depend upon the load.

10 ASSIGN @Ps to 705

20 INPUT "ENTER OPERATING VOLTAGE",V1

30 INPUT "ENTER TOTAL CURRENT LIMIT",Ilim

40 C = Ilim/2

50IF V1 > 7 THEN V2 = 20.2

60IF V1< =7 THEN V2=7.07

70IF Vl < = 2.5 THEN V2 = V1

80OUTPUT @Ps;"CLR;ISET1,";C;";VSET1,";V1

90OUTPUT @Ps;''ISET2,";C;"VSET2,";V2

100WAIT 1

110OUTPUT @Ps;"VOUT?1"

120ENTER @Ps;Vout

130OUTPUT @Ps;"IOUT?1''

140ENTER @Ps;Ioutl

150OUTPUT @Ps;"IOUT?2"

160ENTER @Ps;Iout2

170PRINT "OUTPUT VOLTAGE IS ";Vout

180PRINT "TOTAL OUTPUT CURRENT IS ";Ioutl + Iout2

190END

Programming with a Series 200/300 Computer103