7. External programming
The output voltage, current and OV protection can be adjusted externally with programming voltages.
The voltage and current can also be adjusted by means of resistance programming.
7.1 External voltage programming
The programming voltage source is connected with its minus lead to TB4-8 and its plus lead to
TB4-15. To activate the external mode the switch ‘‘EXTERN’’ is pushed. The yellow LED
indicatior illuminates if the external mode is active.
The programming voltage may have values between 0 and + 10V. The output voltage is linear
and proportional to the programming voltage.
The load for the auxiliary source is 150µA.
NOTE
1. When the programming line is interrupted during operation, the output voltage drops to zero.
2. When using long programming leads it is recommended to use shielded cable in order to
prevent external distortions. It is also recommended to apply accordingly blocking capacitors to
the terminals in case of oscillation due to the inductivity of long programming leads.
3. Ripple, stability and Tc of ARGOS depends on the auxiliary source specifications.
7.2 RVP (Resistance Voltage Programming)
The output voltage can be externally programmed using a 0 to 10 kOhm resistance. The
configuration is shown here under.
TB3-8
Rprog
0...10kOhm
TB3-14
TB3-15
The output of the power supply is :
Vout = (Rprog/10) x Vmax Rprog in kOhm; Vout, Vmax in volt
NOTE:
a) In order to prevent stability fault it is recommended to use oversized resistors (eg. 2W) with a
Tc of <=20ppm/¦C.
b) During RVP mode the sliding switch S1 on the rear panel must be positioned on the right side
and the ‘‘EXTERN’’ switch on the frontpanel in the position INTERN (not pushed).
c) With Rprog = 12kOhm will Vout = 1.2xVmax
d) In case Rprog>20kOhm (interruption), the output voltage is programmed to zero.
e) RVP and Tracking modes are effective simultaneously. The output voltage always results
from the highest programmed value. If no voltage is on TB3-5 (TRACKING) the RVP mode is
not influenced by the tracking mode (see Tracking mode).
f) When the sliding switch S1 is in the left position the output voltage is adjusted with the control
on the frontpanel. In this case Rprog has to be removed.
Argos 1200
Page
8
von
16
ISSUE
07/05
