Ea Elektro Automatik EA Elektro-Automatik EA-EL 9750-75 HP Electronic Load 0 - 75 A 0 - 750 Vdc 0 - 7200 W 33200251 Ficha De Dados

Códigos do produto

33200251

Instruction Manual

EL 9000 HP Series

Date: 10-31-2011

Figure 12

Figure 12 shows a possible progression of a set value

(U, I, P or R) with adjustable pulse widths and variable

amplitude. The rise/fall time is also adjustable, but is

equal for A and B.
If the rise/fall time is set to minimum, the signal of the

pulsed operation is a nearly ideal square wave. Figure

12 is only a clarifying view. The real progression of,

for example, an input current which is pulsed with a

frequency of 1kHz, will differ more or less. It depends

on many circumstances, like the regulation time of the

feeding power supply, the regulation time of the load, line

impedances etc.
In „pulsed“ operation the actual values are also pulsing

and the values constantly change in the display, so they

are not clearly readable.Thus the actual values are now

only indicated at pulse times >=1s (A and B each) and

can be read quite clearly by looking at them. Internally the

actual values are measured much more often (every few

milliseconds). They can always be read via an interface

card, but they are still constantly changing and are not

strictly assigned to level A or B and could thus also be

measured during rise or fall.

6.7.4 Rise/fall time

The rise and fall times are equal and are thus conside-

red as one value. Also see figure 10. It is continuously

adjustable in a range of 30µs...200ms. The step width is

changing from µs to ms over the whole range. The error

lies at max. +10%.
The time is displayed as slew rate in the format ∆value/

time. Example: the set value of A has been set to 40A

and the one of B to 20A, then a current leap of 20A is

generated in a time x, for instance 100ms. The display

then shows 20A/100ms. The ∆value is not adjustable at

this point.
Note: the pulse widths of A and B should always be

greater than the rise/fall time, else the pulsed signal

would result in triangle-shaped wave form or something

else. For example, a pulse width of 100ms for A and B

and a rise/fall time of 100ms creates a triangle-shaped

signal with a period time of 200ms.This might be wanted

in certain applications and is thus not limited or influenced

by the device.

Handling the device

6.8 The battery test mode

Introduction
Mode „Battery“ is intended for battery tests, by connecting

a battery to the load and discharge it definedly. The ave-

rage current is measured and the elapsed time is counted

and then displayed as the consumed battery capacity in

Ah. The voltage supervision, together with the adjustable

undervoltage shutdown threshold

Ulow

, prevents the

battery from being deeply discharged. This threshold

needs to be adjusted at least once. If it is exceeded du-

ring the test, the load input is automatically switched off

and the time counter is halted. No more current is drawn

from the battery. If the threshold is set to greater than the

battery voltage, the test can‘t be started.
Selecting the regulation mode
The preselected regulation mode determines the set

values that can be adjusted for the test. The mode can

be changed at any time,

even while the test is running.

Doing so will reset the whole test, along with time counter

and Ah value.
Usage
Before and during the test you can adjust the set value of

the (pre)selected regulation mode (CC, CR or CP) and the

undervoltage shutdown threshold

Ulow

. The value to set

is selected with

Selection(5) and adjusted with Setting(6).

The displays shows the elapsed test time in the format

Hours:Minutes:Seconds (HH:MM:SS), as well as the

consumed capacity in Ah.
Calculation of the Ah value
The ampere hours value (withdrawn electric charge) is

calculated from the average of the last two measurings

of the input current and the elapsed time.
Start/pause/stop the test
The test ist started by pressing the pushbutton

Input on/

off(4) and either stops after 100 hours are counted or

the battery voltage exceeds the undervoltage threshold.

Another press of the button

Input on/off(4) during the test

halts it, another press will continue the test. A reset of the

time counter is done by leaving the battery test mode by

switching the selector

Level Control(3) to position Level

A/B or Setup or by switching to a different regulation

mode with

Mode(2).

Note: if external control by analogue interface is activated

(pin REMOTE = low) while the battery test is running, the

test is aborted. After external control has left again and if

the switch „

Level Control“ is still in position „Battery“, the

test can be started again. Time and Ah value are reset.
Note: if the regulation mode is changed by Mode(2), all

other set values that are not adjustable for the selected

regulation mode are set to default values in order to let

the test mode work correctly. Hence the setting

Keep set

values

is ineffective here.

The example in figure 13 shows that the current of 100A

can not be reached because the power limitation has

become active (example of a 2400W model).
Note: The time display is not 100% exact. The deviation

of the displayed time to the actually elapsed time can be

1-2 seconds per hour.