Application
Version 1
RES-408
Page 7
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Application
This RESISTRON temperature controller is an integral part of the "series 400", the outstanding feature of which is
its microprocessor technology. All RESISTRON temperature controllers are used to control the temperature of
heating elements (heatsealing bands, beaded bands, cutting wires, heatsealing blades, solder elements etc.), as
required in a variety of heatsealing processes.
The controller is most commonly used for impulse-heatsealing PE and PP films in:
• Vertical and horizontal f/f/s machines
• Pouch, filling and sealing machines
• Film wrapping machines
• Pouch-making machines
• Group packaging machines
• L-sealers
• etc.
The use of RESISTRON temperature controllers results in:
• Repeatable quality of the heatseals under any conditions
• Increased machine capacity
• Extended life of the heatsealing bands and teflon coatings
• Simple operation and control of the sealing process
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Principle of operation
The resistance of the heatsealing band, which is temperature-sensitive, is monitored 50x per second (60x at 60Hz)
by measuring the current and voltage. The temperature calculated with the help of these measurements is dis-
played and compared with the set point.
The primary voltage of the impulse transformer is adjusted by phase-angle control if the measured values deviate
from the set point. The resulting change in the current through the heatsealing band leads to a change in the band
temperature and thus also its resistance. This change is measured and evaluated by the RESISTRON tempera-
ture controller.
The control loop is closed: ACTUAL temperature = SET temperature. Even minute thermal loads on the heat-
sealing band are detected and can be corrected quickly and precisely.
The thermoelectric control loop which is formed has a highly dynamic response because purely electrical variables
are measured at a high sampling rate. A very wide secondary current range can be controlled with only minimal
power loss - a considerable advantage - because power is controlled on the primary side of the transformer. This
allows optimum adaptation to the load and to the required dynamic range despite the exceptionally compact
dimensions of the controller.
PLEASE NOTE!
RESISTRON temperature controllers play a significant role in enhancing the performance of modern machines.
However, the full benefit can only be obtained from the advanced technology offered by this control system if all