KERN & SOHN VFS 2T1 Addendum - Manual (Page 10)

EPM205 - Technical reference - Rev. A Page 10
Advanced Printing Systems
3.6. Heating time calculation
The following formula allows to calculate the heating time T
on
depending on driving voltage VH:
on
0
0
0
2
com av ic l
2
H av
T =
E
P
= E *
(N * R + R + R + R )
V * R
Where:
E
0
is the nominal energy
V
H
is the driving voltage
R
av
is the average resistance
N is the number of dots energized simultaneously
R
com
is the common resistance (0.05 Ω)
R
ic
is the driver saturated resistance (10 Ω)
R
l
is the lead resistance (10 Ω)
3.7. Thermistor
When performing continuous printing, it is recommended that the supply energy be reduced so that the
substrate temperature monitored through the thermistor will remain below 65°C.
The thermistor specification is the following:
- R25, resistance at 25°C: 30 KΩ ±5%
- B value: 3950 KΩ ±2%
- Operating temperature: -20°C to +80°C
- Time constant: Max. 30 s (in the air)
Then the resistance value, R, versus temperature, T (in °C), is given by the formula:
R ( T ) = R 25 * e B* (
1
T + 273
-
1
25 + 273
)