B&K Precision 1651A - Manual - Manual (Page 36)

32
APPLICATIONS_______________________________________________________________________________________
Two Differing Positive Voltages With a Common
Negative (Refer To Fig. 12)
Many electronic circuits require two different positive
voltages with a common negative. A typical example of this
would be a device that uses both TTL (+5 V) and analog
(typically +15 V) circuitry. Using both supplies, two differing
positive voltages with a common negative are obtained as
follows:
1. Select the INDEPendent operating mode and set the A/B
Metering switch to monitor the “A” supply.
2. Set the desired voltage and maximum current for the “A”
supply using the “A” VOLTAGE and CURRENT
controls.
3. Set the A/B Metering switch to monitor the “B” supply.
4. Set the desired voltage and maximum current for the “B”
supply using the “B” VOLTAGE and CURRENT
controls.
5. Connect the ground straps between each supplies’
negative terminal and the GND (green) terminal.
6. Turn off the power supply and the equipment to be
powered during hook-up.
7. Connect the positive polarity inputs of the circuit to be
powered to the positive (red) terminal of the supply.
Connect the common negative input of the circuit to be
powered to either the supply’s negative (black) or GND
(green) terminal.
NOTE
The example in Fig. 12 uses the “B”
supply to provide the +5V, so that
current can be monitored on the mA
Fig. 12. Typical Hook-Up Using Two Differing
Positive Voltages and a Common Negative.
meter. If the current requirements of
the +5 circuits exceed 0.5A, then the
FIXED 5 V output should be used.