Connections For Operation - Lambda LJS-10-V Series Instruction Manual

OPERATING INSTRUCTIONS
BASIC MODE OF OPERATION
This power supply operates as a constant voltage source provided the load current does not exceed the
rated value at 507C. For continuous operation, load current must not exceed the rating for each ambient
temperature. When rated load current is exceeded, voltage decreases towards zero and the current at short
circuit is held to a safe value.
CONNECTIONS FOR OPERATION
NOTE: Make all connections to the unit before applying input power.
Ground Connections. The Lambda power supply can be operated either with negative or positive output
terminal grounded. Both positive and negative ground connections are shown in the diagrams for all suggested
output connections illustrated in this manual.
Connection Terminals. Make all connections to the supply at the terminal block on the front of the supply.
Use a Reed-Prince no. 2 screwdriver on terminal screws. Apply input power to input terminals; always connect
the ungrounded AC or DC lead to the bottom terminal.
The supply positive terminal is brought out to terminal +V. The supply negative terminal is brought out
to terminal -V. Recommended wiring of the power supply to the load and selection of wiring is shown in
figures 1 through 9. Selection of proper wiring is made on the basis of load reguirements. Make all perform-
ance checks and measurements of current or voltage at the front output terminals. Connect measuring
devices directly to terminals or use the shortest leads possible.
Remote on-off control is brought out to terminal RV1 and terminal RV2. Either digital command or
switch closure can be used for on-off control. Logic "0" or "close" for ON and logic "1" or "open" for
OFF. When digital command is used, RV2 should be connected to the incoming signal ground. Maximum
command voltage is +24 volts. Proper remote on-off control connection is shown for all suggested output
connections illustrated in this manual.
SUPPLY LOAD CONNECTIONS
Connections for Operation as a Constant Voltage Source
The output impedance and regulation of the power supply at the load may change when using the supply
as a constant voltage source and connecting leads of practical length are used. To minimize the effect of the
output leads on these characteristics, remote sensing is used. Recommended types of supply load connections
with local or remote sensing are described in the following paragraphs.
Refer to figure 1 to determine voltage drop for particular cable length, wire size and current conditions.
Lead lengths must be measured from supply terminals to load terminals as shown in figure 2.
Local Sensing Connection, Figure 3. Local sensing is the connection suitable for applications with relatively
constant load or for applications with short power output leads.
Remote Sensing Connection, Figure 4. Remote sensing provides complete compensation for the DC voltage
drops in the connecting cables. Sensing leads should be a twisted pair to minimize AC pick-up. A 2.5 mf
elect., capacitor may be reguired between output terminals and sense terminals to reduce noise pick-up.
Programmed Voltage Connections, Using External Resistor, Figure 5. Discrete voltage steps can be pro-
grammed with a resistance voltage divider valued at a nominal 1000 ohms/volt change and a shorting-type
switch as shown in figure 5. When continuous voltage variations are reguired, use a variable resistor with the
same 1000 ohms/volt ratio in place of the resistive voltage divider and shorting-type switch. Use a low
temperature coefficient resistor to assure most stable operation.
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