Relay Interface for Kenpro Rotators

This relay interface connects a rotator controller with 5V control outputs, such as SatBox or the Fox Delta ST2-USB, to an AC motor rotator.
Operation has been tested with the Kenpro KR-400 and KR-500. For other models, compatibility must be checked, including the motor drive voltage, wiring, and relay contact ratings.

Rotator Relay Interface Selling Price Available in mid-November (Excluding EMS shipping time)
Bare PCB	Approx. US$13.33
Assembled board	Approx. US$30.00
Assembled board with power supply	Approx. US$38.00	Includes a 5V power supply for replacing the potentiometer with an AS5600 magnetic encoder
EMS shipping	Ask

USD amounts are approximate, converted at US$1 = JPY 158.06 (October 19, 2026), and rounded to two decimal places. Exchange rate source. Please confirm the final USD amount when ordering.

Contact me

Choosing an Option

• Bare PCB：For those who wish to source the components and solder and assemble the board themselves.
• Assembled board：The relay interface section is assembled. The 5V power supply circuit for the AS5600 is not needed when using the original potentiometer.
• Assembled board with power supply：Includes a 5V power supply circuit for use when replacing the potentiometer with an AS5600 magnetic encoder.

Before Connecting or Ordering

This board switches control signals through relay contacts. Before wiring the connectors, check the circuit diagram and terminal assignments of the equipment being connected.

When making an inquiry, please tell me your rotator model, the controller you use, whether you plan to use an AS5600, and which option you would like. Please confirm shipping costs, shipping method, lead time, payment method, and included accessories before ordering. Comments at the bottom of this article are published after approval, so please do not include personal information such as your address or telephone number.

The download counts for the KiCad design files were 54 for the Japanese version and 39 for the English version when this article was written (October 19, 2026), so I think there may be some demand.

Assembled board

Components Used
5V relay, SRA-05V-CL	4 pcs.
Film capacitor, 104 (0.1µF), 250V	4 pcs.
1/2W 100-ohm resistor	4 pcs.
1N4007 diode	4 pcs.
KF2510 connector, 5-pin	4 pcs.	The photo shows an 8-pin connector, but a 5-pin connector can be used.
KF2510 female connector	4 pcs.	With 20cm cable

When using the original potentiometer, the components for the AS5600 5V power supply circuit on the right side of the photo are not used.

With a 5V Power Supply for Replacing the Potentiometer with an AS5600 Magnetic Encoder

Connect relay output J3 to the points outlined in red

References
SatBox
　https://ji1fgx.com/en/260909.html
Replacing the Potentiometer in a KR-500 Elevation Rotator with an AS5600 Magnetic Encoder (June 16, 2026)
　https://ji1fgx.com/en/260604.html
　https://ji1fgx.com/en/260616.html
Interface for Kenpro Rotators KiCAD Data(October 19, 2026)
　https://ji1fgx.com/en/261018.php