7
Operation - Auxiliary Output
Output Voltage
The output voltage can be set between 1.5V and 5.0V using the front panel rotary adjustment
beside the centre terminals. With the right-hand main output OFF, pressing the SHOW AUX
PRESET button will display the AUX output voltage and current limit on the right-hand meters.
Current Limit
The output will go into current limit at between 5A and 6A; the UNREG lamp lights in this
condition.
Protection
The output has intrinsic short-circuit protection and is protected from reverse voltages by a diode;
the continuous reverse current must not exceed 3 Amps, although transients can be much higher.
The output is protected against externally applied forward voltages of up to 7V.
Operation - General
Connection to the Load
The load should be connected to the positive (red) and negative (black) output terminals. Both
are fully floating and either can be connected to ground.
Series or Parallel Connection with Other Outputs
The outputs of the power supply are fully floating and may be used in series with other power
supply units to generate high DC voltages up to 300V DC.
The maximum permissible voltage between any terminal and earth ground (
) is 300VDC; the
maximum permissible voltage between either terminal of one output and any terminal of another
output on the same supply is also 300VDC.
WARNING!
Such voltages are exceedingly hazardous and great care should be taken to shield
the output terminals for such use. On no account should the output terminals be touched when
the unit is switched on under such use. All connections to the terminals must be made with the
power switched off on all units.
It should be noted that the unit can only source current and cannot sink it, thus units cannot be
series connected in anti-phase.
The unit can be connected in parallel with others to produce higher currents. Where several units
are connected in parallel, the output voltage will be equal to that of the unit with the highest
output voltage setting until the current drawn exceeds its current limit setting, upon which the
output will fall to that of the next highest setting, and so on. In constant current mode, units can
be connected in parallel to provide a current equal to the sum of the current limit settings.
Ventilation
The power supply is very efficient but nevertheless can generate significant heat at full power.
The supply relies on convection cooling only and it is therefore important that ventilation is never
restricted if performance and safety are to be maintained.
