- 9 -
4000 4 332-EN-GE - 01/22
5
DC output
6
Current adjustment
7
Current range selection
8
Voltage adjustment
9
Voltage range selection
3-2 BACK PANEL DESCRIPTION
10
Main input voltage cord
11
Main input voltage cord housing
4 - WORKING PRINCIPLE
4-1
WORKING LIMITS
In the case of jointly use of AC and DC outputs, the total output power should not exceed 120 W.
Temperature shutdown can appear if this power is overridden.
3 possible cases :
- AC current output is stopped (internal circuit breaker in serie on the outputs).
- DC current output falls to 0 Volt and 0 Amp (temperature control of the heat sinks)
- The power supply completely switched off (internal circuit breaker on the transformer)
In any cases, disconnect the uses and wait for the automatic rearmament that will start as soon as the internal
temperature will be low enough.
4-2
REMINDER ON RECTANGULAR CHARACTERISTICS
A power supply that can work with constant voltage or constant current is said rectangular characteristics (D. 2).
The transition from «constant voltage»operation towards «constant current»operation is automatic according to the
adjustments of Vs and Is and to the load applied to the output.
If load resistance RL is superior to the Vs/Is ratio, the power supply works in constant voltage for the output voltage
value chosen and with a current limit to Is.
If RL varies from infinite to Vs/Is, I can vary from 0 to Is (example I1) and output voltage
is constant.
Thus, to make the power supply works in constant voltage, the output current should
be inferior to the selected limit current.
In the contrary case, the power supply changes its way of operation and passes in
constant current. If load resistance RL is inferior to Vs/Is ratio, the power supply works
in constant current, for a selected current value and with a voltage limit to Vs. If RL varies
from 0 to Vs/Is, V can vary from 0 to Vs and Is = constant (example V1). Thus, to
make the power supply works in constant current, the output voltage adjustment must
be at the maximum of the specified values.
Caution
: when the adjustments of the output limit voltage and current are such as the load resistance is equal to
the Vs/Is ratio, this can lead to an instability of operation.
5 - WORKING
5-1
MOUNTING AND PLACING OF THE INSTRUMENT
There is an handle on the top of the power supply to make the transportation easier.
For an optimal operation, the power supply must stand on its 4 rubber thrusts. The back panel must be widely cleared
not to block the air flow of the fan.
Unfold the main power cord of its housing and connect it to a 230 V AC socket, your instrument is ready to work.
5-2
USE
Push on the
«I»
of the ON/OFF switch [
1
], the indicators light up, your power supply is working.
ALR3002M has 2 distinct and completely separated power supplies.
5-2-1 AC outputs
The three AC outputs [
2
] 6, 12, 24 V with common point 0 are protected by thermal circuit breaker (PTC type) that
works as soon as the output current exceed 5 A on one of the outputs. The rearmament is automatic as soon as
the defect is deleted and the circuit breaker temperature is back to normal.
It’s possible to use several outputs if the current sum does not exceed 5 A.
5-2-2 DC outputs
Voltage and current values available on the DC output [
5
] are adjustable by the knobs [
6
] [
7
] [
8
] [
9
] and displayed
on [
3
] [
4
].
Constant voltage use
Adjust the current to max or to max desired value by [
6
] [
7
].
Select the desired voltage range by [
9
] : 5, 6, 12 or 30 Volts.
Adjust the voltage to the desired voltage by [
8
] on the display [
3
].
RL=Vs/Is
RL>Vs/Is
V
Vs
V1
D.2
RL>Vs/Is
I1
Is
I
ENGLISH
