A customer’s equipment used an operator control panel employing Denso D880 illuminated LCD keyswitches. The equipment was becoming unusable because these keyswitches were failing. They were obsolete and even reclaimed devices could not be obtained. Our solution was a redesign of the electronic modules containing them, based around SMARTSWITCH^TM devices (IS-15 series) from NKK.

The alternative keyswitch was a long way from being an exact equivalent of the original device. Mechanically it was slightly larger, but the difference was so small that it could be accommodated by using a modified front panel, which had the additional benefit of giving the equipment a brand new look. The replacement had both an identical number of LCD segments, and button illumination colours, but a very different control method. Using an Actel A42MX series FPGA and modern ICs instead of the MSI, PALs and discrete devices used in the original design also had a beneficial impact on the power consumption of the replacement module. The reduced PCB area necessary allowed the adoption of a single PCB for each group of switches in place of the stacked PCB construction previously necessary. ASIC Solutions supplied assembled and tested modules through the OEM to the end users of the equipment. The old boards removed from the equipment obviously still had some of the keyswitch devices working, so could be cannibalised to get working switches to repair some degraded devices in other units

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