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Elmo SERVO AMPLIFIER DBP SERIES User Manual

Page 89

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88

DBP - Rev 6/93

Signal input level (R193,R194)

The R/D inputs (Vin rms) are adjusted to the sin/cos. Resolver outputs by:

Resolver output = Vin rms = Vrrms x Transformation ratio

R193 = R194 = Vin rms - 2 - Rstator (Kohm)

(Rstator in Kohm).

When Vinrms<2V, install R193=R194=100 ohm.

The standard R/D converter will not operate for Vin rms<1.8V. Consult factory

for OEM applications.

Velocity Signal

The tracking converter technique generates an internal signal at the output of

the integrator that is proportional to the rate of change of the input angle.

This dc analog output (velocity signal) is buffered and represented at terminal

H/R-12b,E-J3/23. Max output voltage is +8V.

This velocity signal can be internally connected to the summing junction of

the error amplifier by inserting R7 - see Appendix B for more details. However,

the standard procedure does not require closing the velocity loop.

Select maximum actual velocity of the application and calculate the maximum

tracking rate T of the Resolver as follows:

T = rpm x Q / 120

T unit is rps: Resolver electrical revolution per second

Q - number of poles of Resolver ;

rpm - mechanical revolution per minute.

Selecting the Resolution

The resolution can be selected to be 10,12,14 or 16 bits by use of DIP

switches 13 and 14. When selecting the resolution the rps limits should not be

exceeded: