WATSON INDUSTRIES VSG-E469 User manual

Watson Industries, Inc. VSG Bipolar Rev E 02/15/2008
Vibrating Structure Gyroscope
Bipolar Version
Owner’s Manual
1. Description
The Vibrating Structure Gyroscope (VSG) is a solid state, single-axis, angular rate
sensor. The VSG provides a voltage proportional to the rate of turn about its sensitive
axis and requires only DC power for operation.
The sensitive axis is perpendicular to the base of the instrument. Angular rotation
about this axis is sensed by a vibrating ceramic cylinder. Coriolis forces acting upon
the cylinder result in a DC output proportional to the rate of rotation.
2. Characteristics
2.1 Electrical
The input range, sensitivity, and resolution for different versions of the VSG are
given in Table 1.
Table 1
The VSG power requirements are given in Table 2.
Supply
Voltages +8.5 V to +16 V (wrt Pwr. Gnd.)
Current <= 80 mA
Noise and
Ripple DC to 1 kHz: 50 mV pk-pk (max)
Table 2
Nominal
Scale Factor
Part Number
Rate
Input
Range
°/s mV/°/s °/s/V
Resolution
°/s Voltage Range for Full Scale Rate
VSG-E469 ±50 100 10 0.013
VSG-E470 ±100 50 20 0.025
VSG-E601 ±200 25 40 0.05
VSG-E470-500 ±500 10 100 0.13
VSG-E470-1000 ±1000 5 200 0.25
±5 V
Additional scale factors available on request.

Watson Industries, Inc. VSG Bipolar Rev E 02/15/2008
The wiring call-out is given in Figure 1.
Notes: The output voltage (blue wire) is relative to the signal ground (green
wire).
The external reference output (orange wire) is for referencing to a digital
circuit with a maximum load of 1 mA.
The temperature sensor output (yellow wire) gives an output voltage
relative to the power ground (black wire).
Figure 1: Electrical Interface
Load Impedances:
Rate Output: > 100 kΩ
Temperature Output: 14 MΩ
+5 V Ref Output: > 5 kΩ
Temperature Voltage Output
The VSG provides a temperature-dependent output voltage on the yellow wire. This
temperature signal is referenced to the black wire (power ground).
The voltage is proportional to the absolute temperature, and has a scale factor of
approximately 2.1 mV/°C.
Output Voltage (mV) = 2.1 * (T + 273) where T = temperature in °C.
e.g. @ 25°C: 2.1 * (25 + 273) = 626 mV
VSG
Shield
Orange
Blue
Green
Yellow
Red
Black
Shield
+5 V REF OUTPUT
ANGULAR RATE OUTPUT
SIGNAL GROUND
TEMP OUTPUT
+8.5 V TO +16 V SUPPLY
POWER GROUND

Watson Industries, Inc. VSG Bipolar Rev E 02/15/2008
2.2 hysical
The physical dimensions of the unit are shown in Figure 2. A three-point mounting is
provided on the case of the unit. The gyro should be attached by three screws
through the 3.5 mm (0.138”) holes in the mounting feet. To avoid distortion, the gyro
must be attached to a clean, flat surface, and the fasteners must be tightened evenly to
0.5 Nm (0.7 ft.lb.) torque.
Figure 2: VSG Dimensions
2.3 Environmental
The environmental specifications are given in Table 3.
Operating Temperature Range -30°C to +60°C
Survival Temperature Range -55°C to +85°C
Shock Survival 500 g, 10 ms, ½ sine wave
Vibration Operating 5 g rms 20 Hz to 2 kHz
Vibration Survival 10 g rms, 20 Hz to 2 kHz
Table 3
3. Constraints
The VSG case is coupled to power ground via a 100 nF capacitor. Do not apply more
than 30 V between the case of the VSG and power ground.

Watson Industries, Inc. VSG Bipolar Rev E 02/15/2008
The wire bundle is shielded and connected to the VSG case. Watson Industries
recommends that you do not connect to the shield.
The case of the VSG is not hermetically sealed. Avoid the possibility of moisture
entering the case.
The power ground is already connected internally to the signal ground. Do not
connect the ground wires externally.
The VSG, although of rugged design, is a sensitive instrument. Take care when
handling it.
4. Typical Operating Circuits
Figure 3: Typical Configurations
+ RATE GIVES
+ OUTPUT VOLTAGE
VSG
Angular Rate Output
Power Ground Signal Ground
Load (min)
100 kΩ
Output: 0 V ± S/F * Rate Input
+5 V Ref.
Angular Rate Output Ref. In
ADC
(i) Bipolar Output
(ii) Digital Output
Power Ground
VSG
Red
Blue
Green
Black
Black
Blue
Orange
V +
Red
+V

Watson Industries, Inc. VSG Bipolar Rev E 02/15/2008
Warning
Rough handling, dropping, or miswiring this unit is likely to cause
damage.
DISCLAIMER
The information contained in this manual is believed to be accurate and reliable; however, it is
the user’s responsibility to test and to determine whether a Watson Industries’ product is suitable
for a particular use.
Suggestion of uses should not be taken as inducements to infringe upon any patents.
WARRANTY
Watson Industries, Inc. warrants, to the original purchaser, this product to be free from defective
material or workmanship for a period of two full years from the date of purchase. Watson
Industries’ liability under this warranty is limited to repairing or replacing, at Watson Industries’
sole discretion, the defective product when returned to the factory, shipping charges prepaid,
within two full years from the date of purchase. The warranty described in this paragraph shall
be in lieu of any other warranty, express or implied, including but not limited to any implied
warranty of merchantability or fitness for a particular purpose.
Excluded from any warranty given by Watson Industries are products that have been subject to
abuse, misuse, damage or accident; that have been connected, installed or adjusted contrary to
the instructions furnished by seller; or that have been repaired by persons not authorized by
Watson Industries.
Watson Industries reserves the right to discontinue models, to change specifications, price or
design of this product at any time without notice and without incurring any obligation
whatsoever.
The purchaser agrees to assume all liabilities for any damages and/or bodily injury which may
result from the use, or misuse, of this product by the purchaser, his employees or agents. The
purchaser further agrees that seller shall not be liable in any way for consequential damages
resulting from the use of this product.
No agent or representative of Watson Industries is authorized to assume, and Watson Industries
will not be bound by any other obligation or representation made in connection with the sale
and/or purchase of this product.
PRODUCT LIFE
The maximum expected life of this product is 20 years from the date of purchase. Watson
Industries, Inc. recommends the replacement of any product that has exceeded the product life
expectation.

Watson Industries, Inc. VSG Bipolar Rev E 02/15/2008
SERVICE
Watson Industries, Inc. has no service outlets. All service is performed at the factory. In order
to insure prompt service, prior to returning units for repair please call, write or fax:
Watson Industries, Inc.
3041 Melby Road
Eau Claire, WI 54703
ATTN: Service Department
Telephone: [phone]
Fax: [phone]
Email: [e-mail]
Internet: www.watson-gyro.com
All sensors returned under warranty will be repaired (or replaced at the sole option of Watson
Industries) at no cost to the customer other than shipping charge from customer to Watson
Industries (plus any export and transportation charges outside the United States).
In the case of units not under warranty, a flat repair fee will be charged. This fee can be
determined by contacting Watson Industries. Modified units or those subjected to extreme abuse
may be returned to the customer unrepaired.