Using E3640A as current source

Question

There is a E3640A power supply need it to function as a current source. In regular power supplies we set the maximum limit current and the regular voltage we want to output. In the manual shown in the link there is just setting the maximal limit values. There is no option for setting the current we want to output. How can I use it as a current source? They say to go to the limit section and set the maximal voltage and current values. So how does it makes it constant current device? We just set the maximum for both of them. Where am I going wrong with the logic?

Thanks.

Answer 1

If a power supply has been designed to have limited output current, as this one appears to, then the load determines whether it operates in limited voltage or limited current mode.

• If the load voltage is lower than the supply's Vmax limit, say a short-circuit or a low value resistor, then the supply is delivering a constant current at the Imax limit, and dropping its output voltage.
• If the load current is lower than the supply's Imax limit, perhaps an open circuit or a high value resistor, then the supply is delivering a constant voltage at the Vmax limit, and supplying whatever low current the load is demanding.