Solid State Cooling Systems Switchback 6600 CE, Product Manual

Page: 22 / 26

S
WITCHBACK
6600 CE B
IPOLAR
DC P
OWER
S
UPPLY
M
ANUAL
P
ART
N
UMBER
: 52-11147-X
S
OLID
S
TATE
C
OOLING
S
YSTEMS
, 167 M
YERS
C
ORNERS
R
OAD
, W
APPINGERS
F
ALLS
, NY 12590
T
ELEPHONE
: (845) 296-1300 FAX: (845) 296-1303
E
-
MAIL
:
WWW
.
SSCOOLING
.
COM
V
ERSION
: M6
5.5 B
I
-
DIRECTIONAL
O
UTPUT
(P
OLARITY
R
EVERSAL
)
The output terminals are able to reverse polarity under control of a local
or remote polarity signal, as described below. Incidental polarity
reversal of the power supply while in the on state shall not damage the
power supply.
IMPORTANT
Reversal at high power levels may cause the power supply output to
shut off. The power supply fault signal, DB-25 pin 14, will switch to
TTL low when this occurs. Should this occur, the power supply must
be reset by momentarily turning off the input power. To ensure that
the power supply never shuts off during polarity reversal, set output
power to zero for 50 milliseconds prior to reversing polarity.
The power supply polarity is normal (as labeled on the Output Power
terminal block) when a TTL high is applied and switches polarity when
a TTL low is applied. When connected to a Solid State Cooling
Systems' thermoelectric heat exchanger, normal polarity cools the
process.
5.5.1 L
OCAL
P
OLARITY
C
ONTROL
If the power supply is set to regulate to a local set point, DB-25 pin# 22
controls polarity of the output voltage. When this signal is TTL high (or
open circuit), the output polarity matches Figure 3. When this signal is
TTL low, the output polarity is opposite of Figure 3.
5.5.2 R
EMOTE
P
OLARITY
C
ONTROL
If the power supply is set to regulate to a remote set point, DB-25 pin#
17 controls polarity of the output voltage. When this signal is TTL high
(or open circuit), the output polarity matches Figure 3. When this signal
is TTL low, the output polarity is opposite of Figure 3.
5.6 P
ROPORTIONAL
C
URRENT
O
UTPUT
S
IGNAL
DB-25 pin# 21 provides an output voltage signal that is proportional to
the actual output current at a ratio of (I
max
/5 amp)/volt, where I
max
is the
maximum output current set by the user (see Section 4.6). This signal
shall be accurate to 5% of actual output current or ± 0.5 amps,
whichever is greater. This signal has a 1000-Ohm resister in series with
the output and is charged at a maximum of 5.1 VDC.
5.7 +12 V
OLT
S
UPPLY
DB-25 pin 15 pr12 Volts DC power for use in external
circuitry. This is an unregulated supply. The maximum recommended
current is 125 milliamps. Drawing more than 150 milliamps may cause
an auto-reset fuse to shut down the 12 V supply.
CAUTION