SPECIFIED POSITIVE POLARITYOF INPUT CURRENT
Individual coils: 2 +, 1 - or 4 +, 3 -
Series coils: connecting 1 with 4; 2 +, 3 -
Parallel coils: connecting both 1 with 3 and 2 with 4; ( 2, 4 ) + ( 1, 3 )-
Differential coil: connecting 1 with 4; ( 1, 4 ) to 2 < ( 1, 4 ) to 3, when ( 1, 4 ) +; 2 to ( 1, 4 )>3 to ( 1, 4 ), when ( 1, 4 )- ELECTRICAL CONNECTOR
Stock products are equipped with general electrical connectors as shown in the external configuration diagrams, but special connectors are available on special order.
The connector seat has four locations, anyone of which, can be chosen ( except Model FF-101 ). The connector location is over control port 2 if there is no special requirement. DITHER
Dither is an additional signal input to valve as to improve servo valve performance.
The servo valve performance given in this catalog is measured without dither.
Dither will improve servo valve hysteresis and threshold, but will increase internal leakage flow.
It is recommended that dither frequency be 100 to 400 Hz and peak-to-peak dither amplitude be 10%~20% of rated current. SERVO AMPLIFIER
A servo amplifier with DC current output is required to drive torque motor coils.
A deep-current-feedback technology should be employed in servo amplifiers as both to eliminate apparent servo valve gain change and to minimize phase lags due to changes in coil impedance.
609 can supply special servo amplifiers suitable to drive servo valve coils.