LT360 Precision Turntable
User Manual
LT360 Precision Turntable
User Manual
34
10mV/DEG
RS-232
INTERFACE
USB
INTERFACE
ANALOG
OUTPUT
ANALOG
INPUT
DIGITAL
INPUT
10mV/DEG
TTL PULSE
POSITION • DPS • RPM • TORQUE
■
USB Interface
This is a standard type-B connector providing connection to a USB bus. The
USB interface of the LT360 uses only Low-Speed connection speed. This is
more than adequate for control of the turntable.
■
RS-232 Interface
The DB-9F connector is wired as a DCE device, so only a straight-through
cable connection is required to the DTE host (computer). The LT360 does
not require any handshaking, so only the RX and TX signals are used in
addition to Ground. Adapters can be used if needed to provide connection
to DB-25 serial cables.
55
The torque load is equal to the product of radial distance and force, where
force is is the product of mass and acceleration.
F = M•A
T = R•F = R•M•A
M=T/(R•A)
Since the vertical position is changing, gravity is a factor. Depending on the
position of the load, or the rotational direction, the acceleration due to
gravity will add or subtract from the rotational acceleration of the LT360.
From the graphs on the previous pages we find that the average accelera-
tion for the Flat function is about 0.21M/S
2
at 1 RPM and 1 Meter, assuming
the rotation step is at least 3.2 degrees. However the acceleration due to
gravity is 9.8M/S
2
about 50X larger. The actual acceleration due to gravity
changes around the circle from zero at the bottom or top, to the maximum
at the sides. Since the rotational acceleration is so much smaller than the
effects of gravity, we will simply assume the worst case acceleration as equal
to gravity. Therefore the maximum mass load which can be rotated is:
Standard LT360 (49NM), 1Meter
M=T/(R•A) = 49/(1.0•9.8) = 5kg = 11 lbs
HiTorque LT360 (76NM), 1Meter
M=T/(R•A) = 76/(1.0•9.8) = 7.8kg = 17 lbs
