Remotely Controlled Actuator (PIC based)           Code: RK-RCAP

This unit controls a servo motor mechanism to move between two preset limits when a control signal is applied. The range may be set to cover up to approximately 80-90 degrees of rotation. Several modes are available to mimic different functions.

In signal mode, the actuator moves between three positions corresponding to stop, caution, clear on an upper quadrant signal. The actuator simulates the action of a signal arm dropping under gravity, and bouncing at the bottom. Raising the signal is accomplished in a smooth manner, and may constitute a full raise, or half raise to caution. A lower quadrant signal may also be controlled.

Points mode moves the actuator between the two limits either over about 2/3 second, suitable for use as a point controller, or over a longer period, suitable for example to use to control the raising/lowering of a crossing barrier. The unit may be set to move either clockwise or anti clockwise when points are set, so that control switches with inbuilt indicator LEDs may correctly indicate normal/reverse operation.

In WigWag mode, the unit oscillates between the limits. The actuator may be connected to an oscillating target to simulate an operating wig wag crossing signal.

There are double pole changeover contacts on a relay which operates when the unit is activated (that is, when the set/clear control input is high) These contacts may be used for frog switching, or driving ancillary equipment. A logic output is also provided which follows the set/clear input. In signal mode, an output indicates when the signal is displaying caution.

The control switch may be far away from the unit itself, since the control inputs require only 0/12V at less than 2mA to operate. A suitable control switch with inbuilt LED indication is provided with the unit. This requires 15mA at 12V

In Setup mode, the servo motor may be set initially to the centre position, and mechanical linkages adjusted appropriately. Then the two limits may be selected and adjusted individually, for correct operation in the particular application.

The module requires 12v at less than 100mA in standby mode. The current will rise when operating, depending upon the mechanical resistance being overcome by the mechanism. The servo motor mechanism is quoted as having a torque output of 2.3 kgm.cm.





          Kit price for       RK-RCAP: $51-00



Photographs show:
Top: Assembly from component side of circuit board
Above: View showing servo adapted for horizontal motion (point operation in this case)
Left: Showing vertical motion - controlling a signal (Overview and close up of linkage.)



Servo Point Actuator.             Code: RK-SPAP


This unit is the little brother to the above, set up for points operation only. The time of operation is about 1.2 seconds. The unit may be set to move either clockwise or anti clockwise when points are set, so that control switches with inbuilt indicator LEDs may correctly indicate normal/reverse operation. A suitable control switch with inbuilt LED indication is provided with the unit.

The two limits may be adjusted individually, for correct operation. Over-centre springing in the point mechanism is not required.

There are double pole changeover contacts on a relay which operates when the unit is activated (that is, when the set/clear control input is high) These contacts may be used for frog switching, or driving ancillary equipment.

The module requires 12v at approximately 75 mA in standby mode. The current will rise when operating, depending upon the mechanical resistance being overcome by the mechanism. The servo motor mechanism is quoted as having a torque output of 2.3 kgm.cm. The control switch requires 15mA at 12V

The photograph at right shows the servo mechanism mounted beneath a point with linkage passing through the baseboard (top,) and the control board (bottom.)



Kit price for             RK-SPAP: $37-50







All kits available from :
Aztronics Pty Ltd       Phone 8212 6212
170 Sturt St,                     Fax 8212 4212
Adelaide, SA, 5000.                                
email:               sales@aztronics.com.au

Click here to go to Aztronics web site

Information:         David Crosby         david@railwaykits.net

Click Aztronics logo to go to Aztronics Web site, or Click to email     Aztronics     or     Kit designer



Click here to go back to Kits Summary Page

Last updated 3rd February, 2017.
(C) D. Crosby, May, 2011.