Aim TTi EL302P Manuel D'instructions page 8

Efficiency
To improve efficiency at low output levels the overhead voltage to the output regulators is
automatically switched by a relay to a lower voltage; hysteresis at the threshold point prevents
unnecessary switching when the output voltage is set at about that level. Apart from an audible
'click' the user will be unaware that the relay has switched; there will be no disturbance on the
output.
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.
In common with all series regulated single-ended power supplies, the unit is not capable of
sinking current provided from an external source.
If a voltage greater than the set output voltage of the unit is applied from an external source, the
internal regulator will turn off, no current will flow, and the voltage meter will read the applied
voltage. No damage will result providing the applied voltage does not exceed the maximum
output voltage of the power supply by more than 20 Volts. Application of a voltage greater than
this is prohibited.
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 (
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 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.
) is 300VDC; the
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