Samlex America SDC-23 User Manual

DC-DC Step
Down Converter

Owner's
Manual

Please read this
manual before
operating your
converter

Model:

SDC-15

SDC-23

8

8

WARNINGS!

- These units are not battery chargers! Hence, do not connect these units directly to a
battery for battery charging purposes

- These units are designed to be used on negative grounded systems only. Do not
connect the input / output sides to a positive grounded system

- The input and output sides have a common negative ground. Hence, there is no
isolation between the input and the output sides

OWNER’S MANUAL

Non Isolated DC TO DC Converters SDC-15 and SDC-23

IN

IN

OUT

+24V

GND

+

23456789012345678901234567

23456789012345678901234567

-

GND

-

OUT

+13.8V

+

BA TTERY +24VDC NOMINAL

BATTER Y GROUND

LOAD +12VDC NOMINAL(13.8V)
LOAD GROUND

DESCRIPTION

SDC-15 and SDC-23 are non isolated DC to DC converters that convert 24 VDC nominal voltage
(range 20 VDC to 35 VDC) to 12 VDC nominal voltage (13.8 VDC). The input and output sides have
a common negative ground. Hence, there is no isolation between the input and the output sides.
Both the input and output sides are isolated from the chassis of the unit.

PROTECTIONS
Overload / Short Circuit: The units are protected against overload by current limiting. When the

output current reaches the current limit value (please see the specs), the output voltage will drop
and will no longer be regulated. The unit will reset automatically once the overload condition is
removed.
Temperature Compensated Current Limit: As the temperature of the main switching MOSFET
increases, the value of the current limit decreases.
Over V olt age on the Output Side: If the output voltage increases beyond 16.5 V +/-0.5 V, a crowbar
circuit will activate and blow the input side fuse.
Over Voltage / Transients on the Input Side: The input side is protected against over voltage and
transients through a Transient Voltage Suppressor. In case the input voltage exceeds 37 VDC, the
internal fuse will blow.
Reversal of Polarity on the Input Side: In case the input side polarity is reversed, the input side

fuse will blow.