Introduction

The B & K-PrecisionModels 1651A & 1652 Triple Output DC Power Supplies are high quality, general purpose dc power sources. They provide two supplies with a 0-24 volt dc output and one with a fixed 5 volt dc output. The 0-24V supplies are adjustable and are capable of current output of 0-0.5 amp. The fixed 5V supply has a current output of 0-4 amps, allowing it to handle extensive digital logic circuitry. Two panel mounted meters can simultaneously monitor the output current and

output voltage of either of the 0-24V supplies.
The two 0-24 volt supplies can be operated independently or
in one of two tracking modes. In the series tracking mode, the
“B” supply tracks the voltage of the “A” supply. In the series
tracking mode the “A” and “B” supplies are connected in
series, allowing a single output of 0-48V at up to 0.5 amps. In
the parallel tracking mode, the two supplies are connected in
parallel, allowing a single 0-24V output at up to 1 amp.
Both 0-24 volt supplies may be used in constant voltage or
constant current applications. The crossover from constant
voltage to constant current modes is smooth and automatic.
LED’s indicate the Constant Current mode of operation. In
constant voltage applications, a current limit may be preset.
When load variations cause the current to reach the preset
limit, the unit then regulates output current rather than output
voltage. Current limits are adjustable from 6% to 100% of
maximum. In constant current applications, the maximum
voltage may be preset. When load variations cause current to
drop below the regulated value, the unit reverts to regulated
voltage operation at the preset value.	1
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The fixed 5V supply is ideal for powering digital logic circuitry. The 0-4 amp capacity allows the supply to be used for large circuits. Built-in overload protection automatically limits the current output to a maximum of 4 amps. An LED indicator lights when the supply is overloaded.

These supplies exhibits excellent regulation and low ripple characteristics. The circuit design incorporates a pre-regulator, which greatly reduces internal power dissipation at low output voltages.

Reverse polarity protection prevents accidental damage to the power supply from improper connection to an external voltage, and current limiting protects the equipment being powered, as well as the power supply.

The output is isolated from chassis and earth ground, which permits full flexibility of connections. When needed, the (+) or (-) polarity may be strapped to ground, or either polarity may be floated to an external voltage. Additionally, the two “main” volt supplies can be used as a “split supply” with two positive voltages and a common negative, two negative voltages and a common positive, or one positive, one negative, and a common. All of these configurations can be used with either matching (tracking) or differing (independent) voltages.