12/07/16 8:58 am

In this case study, we will review a solution the Mars International Electronics Engineering Team provided to a leading wireless boat lift systems manufacturer.

Business Situation

A Mars International client, GEM Remotes of Naples, Florida is a leader in the field of wireless boat lift control systems. They were looking to add features and improve the product design of their existing remote control transmitter product and their existing receiver control board that is located in the local control box. They desired to reduce the number of parts in inventory while providing enhanced ease-of-use features, improved waterproofing of the remote transmitter, and upgraded motor control capability. The final product designs needed to offer price competitive solutions while providing better, more reliable and field-upgradable products with the flexibility to meet the requirements of both their manual and auto-stop products.

Technical Situation

Mars engineers were challenged to develop a remote control transmitter which improved the TPE to ABS bond of the case as well as battery accessibility.  It also needed LED visibility in sun glare or with Polaroid sunglasses, PCB attachment to the case, and a water seal after battery replacement.

The team was also asked to develop a remote receiver control board which would be common to both the manual 2-motor drive system and the auto-stop 2-motor drive system. The receiver needed to be designed to default to manual mode but would have to support a field upgrade option for configuration to the auto-stop system. Also, the board would have to match the dimensions of the existing control board so GEM Remotes could offer upgrade packages for existing customers. The board design would need to better support the centrifugal switch of the boat hoist motors such that the motors have time to come to a complete stop before being reactivated by the user for operation in the opposite direction. This additional control feature would relieve the potential problem of the motors continuing in the same direction rather than reversing direction as intended by the user. The design team was also asked to design the board so that the boat lift systems could be powered by either 24V AC or 12V DC.

Mars International was asked to obtain FCC Equipment Authorization approval of both products.

Solution & Benefits

Mars International designed the GEM Remote control transmitter so that the 12V 23A battery (10.3 mm diameter and 28.5 mm height) is replaced with two 3V CR2032 batteries (20mm diameter and 3.2mm height). The area required for the battery is reduced by 16%, and the new battery holder provides a more secure fit.  The PCB is heat staked in place so that it is retained during battery replacement. This required conversion of the locating posts to the top cover and removal of the large boss on the back cover. In addition, improved battery accessibility was achieved by moving the assembly parting line on the case. The TPE grade was adjusted to provide a strong chemical bond to the ABS. To provide better visibility of the LED, a cylindrical post was added on the backside of the top cover to extend down around the surface mount LED to funnel the light toward the thinned-out wall. (A black tube was attached as a secondary component around the post since the ABS is yellow). Lastly, the screw configurations and hole diameters were adjusted to reduce stripping on the screw holes and to guarantee a secure seal after being opened for battery replacement.

The receiver board was designed to support operation with or without the auto-stop feature as well as operation with or without a safety photo beam. The board configuration is controlled via dip switch configurations and jump wires and can be field programmed or upgraded as desired.  In addition, the board has learning capability to support different transmitter remote control units. The layout of the board was completed to match the dimensions, mounting screw locations, and connector locations of the existing control board to enable GEM Remotes customer upgrade business. A significant improvement in the new control board was in its handling of the motor control when reversing direction. By programming a delay when switching the unit from up to down or down to up, the behavior of the centrifugal switch in the boat hoist motors was accommodated such that the motors come to a complete stop before they receive a signal to reverse directions. This implementation prevents the potential problem of the motors continuing to run in the same direction when a reverse direction was intended. If the same direction button is pressed, there is no delay. This board is supplied for either a 24VAC or 12V DC supply.

Mars International received the Grant of Equipment Authorization from the FCC and has been in production with these products for more than five years. If you would like to learn more about how the electronics Engineering Team at Mars can help improve the cost and performance of your electronics product, contact us today.

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