HP 6826A Service Manual

A2 BOARD LOCAL/AUTO SWITCH
AUTO POSITION «« - - - » LOCAL POSITION
(TOWARD FRONT) (TOWARD REAR)
FRONT
OF
UNIT
Figure 3-9. Locai/Auto Switch
programming voltages are connected to terminals A14 and
A21 respectively as shown in Figure 3-8. The positive or
negative output current will vary linearly with changes in
the programming voltages. The output current varies at a
rate determined by the programming coefficient. For mod¬
els 6826A and 6827A, the programming coefficient is 1 amp/
1 volt. The maximum rated output current for the 6826A
is 1A, therefore, the maximum programming voltage for
6826A is 1 volt. The maximum rated output current for
the 6827A is 0.5A, therefore, the maximum programming
voltage for 6827A is 0.5V.
3-53 SERIES AMD PARALLEL CONNECTIONS
3-54 The following paragraphs describe the connections
required for combining BPS/A's for series and parallel oper¬
ations. These connections are employed whenever it is re¬
quired to extend the voltage/gain or current capability be¬
yond one supply. For series operation, the total output
voltage/gain is the sum of the voltages/gains of the individ¬
ual supplies. For parallel operation, the total output current
is the sum of the output current from the individual supplies.
For series or parallel operation, the BPS/A's must be opera¬
ted in the same mode (power supply, variable gain amplifier,
or fixed gain amplifier). Also, each supply must have its
Auto/Local switch A2S1 (see Figure 3-9) in the Local posi¬
tion (pushed toward the rear of the instrument). Note that
the external signal applied to the A1 and A2 terminals is in¬
ternally disconnected when the BPS/A's are in the power
supply mode.
3-55 Series Connections. Two or more supplies may be
connected in series to obtain a higher voltage/gain than is
available from a single supply, Figure 3-10 illustrates the
series connections for three supplies. Each of the supplies
must be adjusted in order to obtain the desired output/
voltage gain.
3-56 Parallel Connections. Parallel operation of BPS/A
is possible because of the constant voltage/constant current
crossover feature. Two or more power supplies can be con¬
nected in parallel to obtain a total output current greater
than that available from one power supply. The total output
current is the sum of the output currents of the individual
power supplies. The load must be selected so that the current
limit of one supply is exceeded allowing it to operate in the
constant current mode. The output CURRENT controls of
each power supply can be separately set. The output voltage
controls of one power supply should be set to the desired
output voltage; the other power supply should be set for a
3-9

HP 6826A Specifications

General

Brand	HP
Model	6826A
Category	Power Supply
Language	English