User guide
ServoTube 25/38 module User Guide
Appendices
Page 38
Power dissipation Power dissipation is the maximum power that can be dissipated by the forcer when the forcer phases are at
their maximum operating temperature, the ambient temperature is 25°C, the forcer is not moving and there
is no forced cooling. It is quoted with and without the addition of a 25 x 25 x 2.5cm heatsink plate mounted
with thermal grease to the mounting surface of the forcer.
Maximum phase
temperature
Maximum phase temperature is the maximum operating temperature for the forcer phases. It is limited to
provide a safe operating temperature for the magnets.
Rthphase-houslng Rthphase-houslng is the temperature rise from the forcer housing to the forcer phases for an input power of
1 watt to the forcer. The forcer is not moving, there is no forced cooling and no additional heatsinking.
Rthhousing-ambient Rthhousing-ambient is the temperature rise from ambient temperature to the forcer housing for an input
power of 1 watt to the forcer. The forcer is not moving and there is no forced cooling. It is quoted with and
without the addition of a 25 x 25 x 2.5cm heatsink plate mounted with thermal grease to the mounting
surface of the forcer.
Thermal time constant Thermal time constant is the time taken for the forcer phases to cool to 36.8% of the difference between
forcer phase and ambient temperatures when there is no current owing, the forcer is not moving there is
no forced cooling and no additional heatsinking.
ABBREVIATIONS
The abbreviations used in this Guide are listed in the following table.
Apk Ampere peak PCB Printed circuit board
Arms Ampere root mean square PUR Polyurethane
AWG American Wire Gauge PVC Poly Vinyl Chloride
COS cosine s second
d.c. direct current SIN sine
EMC Electro-Magnetic Compatibility TYP Typical
EMF Electro-Motive Force UL Underwriters Laboratory
kg kilogramme V Volt
m metre Vpk Volt peak
mA milliampere Vpk-pk Volt peak to peak
mH millihenry Vrms Volt root mean square
mm millimetre W Watt
MTG Mounting °C degrees Celsius
N Newton mm micrometre (micron)
PTC Positive Temperature Coefcient