SteelDriveII controller unit. The compensation period and ∆
T
threshold is also adjustable. Once
set, the compensation can then also be used in standalone mode of operation (without a connected
computer). When the automatic temperature compensation is enabled, the focuser will do a correction
movement every period, if the temperature difference threshold ∆
T
is exceeded.
1.4
12V/1A PWM Power Output
The SteelDrive features a 12V/1A power output. Dew-heaters up to 10W may be directly attached
to the SteelDrive controller (with optional adapter cable). The power can be controlled by the PWM
setting. Other uses are also possible. The default PWM value may be set via PC software and also
used in standalone mode of operation. (Second board revision enables the use of up to 20W heaters
if a stronger power supply is used)
1.5
Standalone PID Controller
A further enhancement of the fast PWM power output is the built-in PID (proportional, integrative,
derivative) controller. Each of the two temperature sensors sockets as well as the average of both
may be used as the input of the PID controller. It enables the precise temperature control of eg.
dew-heaters, optical filters and instruments with
±
0
.
1 degree accuracy. Controlling the dew heaters
temperature little above the dew-point, minimizes temperature gradient induced stress in the telescope
structure. This can be automatically set, eg. on bootup the controller will always keep the temperature
of a dew-heater a given offset (eg. 4
◦
C) above the ambient temperature.
1.6
Superior built quality
The mechanical parts are made in-house out of black anodized, CNC milled aluminum. High quality
electronic components with adequate ratings are used for the electronic boards which are also designed
and produced in Germany. The electronic boards have been further protective coated.
1.7
Low power consumption
The motor current is automatically reduced while in holding state (adjustable). The SteelDrive then
consumes approximately 0.7 W.
1.8
Intuitive Operation
The intuitive hand control enables the user to quickly change between normal speed, jogging mode
(number of steps are also configurable via software) and single step mode. The configuration of limits,
saving of and goto a known focus position as well as temperature compensation toggling are also
available from the hand controller. The backlight illmuniation of the keypad and status LEDs are
dimmable.
1.9
Customizable
The SteelDrive II enables power users to customize a lot of settings from temperature compensation,
PID control to the adjustment of stepper motor settings. Users with multiple telescopes can use
multiple motor units with only one controller one at a time. The setting for the different telescopes
are saved and loaded with the SteelGoII software.
4
