B&K Precision models 1685B, 1687B, and
1688B are laboratory grade switching mode
DC power supplies with high current output in
a small, lightweight form factor. These power
supplies provide various configurations of output
voltage and current, and feature rotary encoder
control knobs, which make setting voltage and
current levels fast and precise. Its dual action
push button allows the user to easily set both
coarse and fine, voltage and current levels.
In addition to its constant voltage (CV) and
constant current (CC) modes, these high efficien-
cy DC power supplies offer preset and remote
Features and Benefits
■Automatic CV/CC crossover operation
■Lightweight and compact
■Rotary encoder control for precise voltage and
current setting
■Save up to 3 user-defined voltage and current
presets for quick recall
■PC software for remote control and external
timed programming
■Analog remote control function
■USB interface
■Front panel auxiliary output
■Overvoltage, overtemperature, and overload
protection
Switching DC Power Supplies
Models 1685B, 1687B & 1688B
Data Sheet
www.bk prec ision.c om
Technical data subject to change
© B&K Precision Corp. 2012
control modes. Save up to three different presets
of voltage and current values for quick recall. For
remote control, an analog remote control
terminal is accessible on the rear, or use the USB
interface to communicate with the power supply
via PC software or remote commands.
These features make the 1685B Series suitable
for a wide range of applications including
production testing, telecommunications, R&D,
electronic field service, and university labs.
Outputs / Model 1685B 1687B 1688B
Variable Output Voltage 1 - 60 V 1 - 36 V 1 - 18 V
Variable Output Current 0 - 5 A 0 - 10 A 0 - 20 A
Rear Panel
Front Panel
Switching DC Power Supplies
Models 1685B, 1687B & 1688B
Have peace of mind knowing that these power
supplies come with built-in OVP (overvoltage
protection), OTP (overtemperature protection),
and OLP (overload protection) circuitry. These
protections help prevent serious damage to
equipment in case of power supply failure
Fully Protected
Custom Presets
Flexibility & PerformanceDesigned to Make Your
Work Easier
Main output
terminal Recall preset switch
Analog remote
control terminal
USB device port
Mode selection
switch
Quickly use common voltage and current settings
with a flip of the Recall preset switch. Up to
three different presets can be set and recalled.
Analog Remote Control Capability
Use the included connector to wire up to an
external variable DC voltage source or variable
resistor to remotely control the power supply’s
output voltage and current or to turn the
output on/off.
PC Connectivity
Control your instrument through remote
control PC software or use programming
commands to communicate with your
instrument.
Cooling fan
LED indicators for
constant voltage and
constant current modes
Rotary encoder knobs for
quick and precise setting
of voltage and current
Bright, dual LED displays
Rear control indicator Auxiliary output terminal
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Switching DC Power Supplies
Models 1685B, 1687B & 1688B
v080619
Specifications
Note: All specifications apply to the unit after a temperature stabilization time of 15 minutes over an ambient temperature range of 23 °C ± 5 °C.
Models 1685B 16 87B 168 8B
Output
Variable Output Voltage 1 – 60 V 1 – 36 V 1 – 18 V
Variable Output Current 0 – 5 A 0 – 10 A 0 – 20 A
Voltage Regulatio n
Load (0-100% Load) ≤50 mV
Line (90-132 VAC, 170-264 VAC Variation) ≤20 mV
Current Regulation
Load (10-90% Rated Voltage) ≤100 mA
Line (90-132 VAC, 170-264 VAC Variation) ≤50 mA
Ripple & Noi se
Ripple & Noise Voltage (rms) ≤5 mV
Ripple & Noise Voltage (peak-peak) ≤50 mV
Current Ripple & Noise (rms) ≤30 mA
Meter Type & Accuracy
Voltage Meter 3-Digit LED Display ± 0.2% + 3 counts
Current Meter 3-Digit LED Display ± 0.2% + 3 counts
Othe r
Input Voltage 100-240 VAC 50/60 Hz
Full Load Input Current 3.7 A (100 VAC)
1.7 A (230 VAC)
4.6 A (100 VAC)
2.1 A (230 VAC)
4.6 A (100 VAC)
2.1 A (230 VAC)
Efficiency 82% (100 VAC)
86% (230 VAC)
82% (100 VAC)
86% (230 VAC)
81% (100 VAC)
85% (230 VAC)
Switching Frequency 100 – 120 kHz
Tracking Overvoltage Protections
O/P 1-5 V: set voltage +2 V
O/P 5-20 V: set voltage +3 V
O/P 20-60 V: set voltage +4 V
O/P 1-5 V: set voltage +2 V
O/P 5-20 V: set voltage +3 V
O/P 20-36 V: set voltage +4 V
O/P 1-5 V: set voltage +2 V
O/P 5-18 V: set voltage +3 V
Transient Response Time (50-100% Load) 1.5 ms
Power Factor Correction > 0.95 at optimal load
Cooling Method Thermostatically controlled fan from zero to full speed
Protections Overload, Overvoltage, Overtemperature
Special Features 3 User-Defined Voltage and Current Presets, Analog Remote Control
External Timed Programming
Max. 20 voltage and current steps
Max. 99 min + 59 sec step time
Max. 999 running cycles
General
Operating Temperature 32 °F to 104 °F (0 °C to 40 °C) ≤ 80% R.H.
Storage Temperature 5 °F to 158 °F (-15 °C to 70 °C) ≤ 85% R.H.
Dimensions (WxHxD) 7.9” x 3.5” x 8.2” (200 x 90 x 208 mm)
Weight 5.2 lbs (2.4 kg)
Two Year Warranty
Supplied accessories Power cord, instruction manual, USB cable, remote control connector
