Specifications - HP 6236B Operating And Service Manual

1-1 INTRODUCTION
1-2 This manual covers two triple output power supply
models, the 6236B and 6237B. Both models are com-
pact general purpose bench supplies that are particularly
useful for powering developmental IC circuits, both linear
and digital. Unless one model or the other is specifically
identified, all information in this manual applies to both
the 6236B and the 6237B.
——— CAUTION
Carefully read Sections II and III of this
manual before attempting to operate the
power supply.
1-3 DESCRIPTION
1-4 These constant-voltage/current-limiting triple
output supplies combine two 0 to ±20V tracking outputs
rated at 0.5 amps with an additional single output that in
the Model 6236B is rated at 0 to+6 volts and up to 2.5
amps, and in the Model 6237B is rated at 0 to +18 volts
and 1 amps. The +20V and -20V tracking outputs can
also be used in series as a single 0 to 40V 0.5-amp output.
Connections to the supply's output and to chassis ground
are made to binding posts on the front panel. The supply's
three outputs share a common output terminal, which is
isolated from chassis ground so that anyone output term-
inal can be grounded.
1-5 All outputs are protected against overload and
short-circuit damage.The+18V output in the 6237B and
the ±20V outputs in both models are protected by circuits
that limit the output current to 110% of its nominal maxi-
mum.The overload protection circuit for the +6V output
in the 6236B has a current foldback characteristic that
reduces the output current as an overload increases until
only 1 amp flows through a short circuit. The 6V output's
current limit depends on the output terminal voltage and
varies linearly between 2.75 amps at 6 volts and 1 amp
at zero volts.
1-6 All controls, meters, and output terminals are
SECTION I
GENERAL INFORMATION
———
1-1
located on the front panel. One voltage control sets the
0 to+6V (or+18V) output and another sets the voltages
of the 0 to +20V and 0 to -20V outputs simultaneously.
These dual tracking outputs are made more versatile by the
provision of a tracking ratio control in addition to the usual
voltage control. With the tracking ratio control turned fully
clockwise to its "fixed" position, the dual outputs have a
fixed 1:1 tracking ratio. As the ±20V voltage control is
adjusted, the voltage of the negative supply tracks the posi-
tive output within ±1%. Turning the tracking ratio control
away from its fully-clockwise position switches the dual
tracking outputs into a variable tracking ratio mode. In this
mode the voltage of the negative output can be set lower
than that of the positive output. The tracking ratio control
allows the negative supply's output to be set to any value
between a maximum that is within 10% of the positive
supply's output and a minimum that is less than 0.5 volts.
Once a ratio is established by the tracking ratio control, the
ratio of the positive output voltage to the negative output
voltage remains constant as the ±20V voltage control
varies the 0 to+20V output over its range.
1-7 The front panel also contains a line switch and a
pilot light, a voltmeter and an ammeter, and a meter
switch that selects one of the supply's three outputs to be
monitored on both dual-range meters.
1-8 In addition to the standard 104-to-127Vac 47-to-
63Hz input, three other line voltage options are available for
nominal inputs of 100, 220, and 240Vac. The supply is
furnished with a permanently attached 5-foot 3-wire ground-
ing type line cord. The ac line fuse is in an extractor type
fuseholder on the rear heatsink.
1-9

SPECIFICATIONS

1-10 Table 1-1 lists detailed specifications for the
power supply.
1-11
OPTIONS
1-12 Options are factory modifications of a standard
instrument that are requested by the customer. The follow-
ing options are available for the instruments covered by
this manual.