GE EPS 3501 XL Manuel D'utilisation page 14

5 Operation
14
Choosing step or gradient programming
Press SET ENTER to confirm step ( ) or use /  keys to choose gradient ( ⁄ ). Confirm
with SET ENTER.
Note that your choice of gradient or step programming applies for all phases within the
program and you will only be asked to choose one of them when programming the first
phase.
Choosing step means that voltage, current and power limiting values are programmed.
The electrophoresis will be controlled by one of these limiting values, which means that
it is run at either constant voltage, current or power. The EPS 3501 XL automatically
switches over the controlling parameter according to programmed limits and
conductivity variations in the system. Thus the controlling parameter can switch within a
phase.
Table 1 and Fig 4 illustrate a step program. The programming and running of this
application are shown as Figs 3 and 7.
3500
2000
Phase 1
1000
1000 Vh
500
Fig 4. Programming the voltage limiting profile in STEP mode. The parameters shown are the same
as those listed in Table 1.
Table 1. The parameters of a step program.
Phase Voltage
number (V)
1 1000
2 500
3 2000
4 3500
Choosing gradient ( ), means that a voltage endpoint for the actual phase is
programmed together with current and power limiting values. A linear voltage gradient
is made with zero (for the first phase) or the programmed endpoint of the phase before
(for the next phases) as starting point and the programmed endpoint as endpoint. The
electrophoresis will be controlled by this voltage gradient provided the limiting current or
power is not attained. The EPS 3501 XL thus automatically switches over the controlling
parameter according to the programmed limits and conductivity variations in the
system.
Electrophoresis Power Supply EPS 3501 XL User Manual 18-1130-22 Edition AD
Phase 3
1000 Vh
Phase
2
120 Vh
1
Current Power
(mA) (W)
10 10
10 5
20 15
30 25
Phase 4
1500 Vh
2
Time (h)
Volthours
(Vh)
1000
120
1000
1500