RESEARCH CONCEPTS RC2K90INT-1 Manual page 7

RC2000 Antenna Controller Interface Box
125 is designed for use with 120 volt AC line voltage. The KBPB-225 is designed for use with 240 VAC
line voltage. These motor drive modules also provide speed control, electronic current limiting, IR
compensation, and dynamic braking. A resistor which is installed in the KBPB called the Plug-In
Horsepower Resistor matches the KBPB's IR compensation and current limit characteristics to the DC
motors used on the antenna. When a KBPB is ordered the horsepower of the motors with which the drive
module will be used should be specified so that the correct horsepower set resistor can be installed. When
the KBPB-225 is used with 90 volt DC motors a modification is performed to the motor drive to limit the
voltage applied to the motors to 90 volts DC. This modification is described in section 4.4. The Operating
instructions for the motor drive module(s) are included with the operating manual for the RC2K90INT-1
and RC2K90INT-2 interface boxes.
The line voltage is applied to the L1 and L2 terminals. The polarity of the voltage applied to the motor and
the operation of the dynamic brake are controlled by the S1, S2, and S3 connections. When the S2
terminal is not connected to either the S1 or S3 terminals the motor drive is in the brake mode. When S2 is
connected to S1 voltage is applied to the armature of the motor (via the A1 and A2 terminals). When S2 is
connected to the S3 terminal a voltage of the opposite sense is applied to the motor.
The armature voltage (and the motor speed) can be varied by connecting a potentiometer across the P1 and
P3 terminals and applying the voltage present at the wiper of the potentiometer to the P2 terminal.
Alternatively, the speed can be controlled by connecting the P2 terminal to the S4 terminal and using the
potentiometer located on the KBPB module labeled AUX (or R14) to vary the speed. When the interface
box is used with the RC2000D dual speed azimuth and elevation control is available by connecting the
terminals on the interface board labeled P1_KBPB1, P2_KBPB1, P3_KBPB1 to the P1, P2, and P3
terminals, respectively, of the KBPB. When used with controllers other than the RC2000D the S4 and P2
terminals of the KBPB are connected together and the azimuth and elevation speed is controlled via the
AUX (R14) pot (for this configuration only single speed azimuth and elevation movement is available).
2K90INT-2 Circuit Board
Figure 3 is a schematic of the 2K90INT-2 circuit board. The circuit which includes relays K2 and K3
generates the contact closures required to control the azimuth axis as described in figure 1 above. The
azimuth +/-36 volt output of the RC2000 is applied to the terminals labeled AZ1_CTL and AZ2_CTL. The
east and west limit switches and their associated steering diodes are connected to the terminals labeled
AZLIM1 and AZLIM2. If limit switches are not used a jumper can be connected between the AZLIM1
and AZLIM2 terminals. When east current flows relay K2 activates which in turn connects the terminal
labeled S2_KBPB1 to the terminal labeled S1_KBPB1. In a similar fashion, when west current flows relay
K3 is activated and the terminal labeled S2_KBPB1 is connected to the terminal labeled S1_KBPB1.
The elevation control circuit consisting of relays K5 and K6 operate in a manner identical to the azimuth
circuit. The control signals are applied via the EL1_CTRL and EL2_CTRL terminals. The contact
closures associated with these relays are available at terminals S1_KBPB2, S2_KBPB2, and S3_KBPB2.
The polarization control circuit is implemented with relays K7 and K8. The control inputs for this circuit
are generated by the an RC2KPOL board installed in the RC2000 antenna controller and are applied to the
circuit board via the P1_CTL and P2_CTL inputs. The contact closures associated with polarization
control are available at connector J8. The user is responsible for using these contact closures to realize a
polarization control scheme for the polarization motors used on his or her antenna.
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