Some industry products advance quickly while others move more cautiously. One industry that has struggled with progressing rapidly, but safely, is the robotics industry. From accidents with self-driving cars to the chess robot that broke a 7-year-old’s finger in mid-2022, companies struggle with how to implement this technology without increasing the potential for harm. Another example that has been tossed around is comparing the progress of cars with computers. For example, if cars had progressed as fast as computers, they would have 600 million horsepower, get 3,700 miles-per-gallon and cost $5,000. The reply to this statement is “yes,” but who would want a car that would crash three times a day?

Figure 1: One industry that has struggled with progressing rapidly, but safely, is the robotics industry. Source: Mallory Sonalert Products

Although the reply is funny, there’s a smidgen of truth in this because safety components don’t necessarily make a change or adopt new technology until it’s certain there will be no effect on reliability and performance. Just because you could save cost and reduce the weight of a panel alarm by eliminating the epoxy backfill, it doesn’t make sense to do this when it will affect the life of the exposed circuit components. Given that safety and reliability are key to industrial electronic audible and visual indicators, what innovation can we expect to see with these devices?

Panel lights underwent a big disruption in technology in the not-too-distant past when the light bulbs were replaced by LEDs, which lowered the current draw and increased reliability. A second big disruption is occurring right now with machine designers adding touchscreens that can display the machine status, eliminating the need for multiple panel LEDs. With less demand overall, panel LED manufacturers are focusing on other growing applications such as over-head lighting, and the result is less panel LED innovation.

Panel alarms have not had huge disruptions in technology like panel lights, and the most reliable and efficient panel alarms still use piezoelectric transducers (piezos) to produce the warning sound. While there have been incremental improvements in the performance, reliability and cost of piezos, most of the panel alarm innovation has been on the electronics side. Ever shrinking and more capable electronic components have enabled a three times reduction in package size, and now a fully functional 120 V AC panel alarm is available, which fits into a 22 mm panel hole. Another improvement is that it used to take three months to make a new sound type because a new circuit had to be designed. That sound development time has now been compressed from months to minutes because that is how long it takes to modify the software inside the alarm’s microcontroller. Essentially, the alarm sound has moved from analog (generated by circuitry) to digital (generated by software). Expect these types of innovations to continue leading to further unique sound offerings, more user control such as the ability to change the volume level electronically, increased functionality including doing more with lights and sound in the same panel mount package, and wireless technology is next on the horizon.

Stacklights (tower lights) are mounted on top of machines and offer both audible and visual indication. These devices combine the best of audible and visual technology by using LEDs in the light stacks, and piezos in the sound stack. Wireless stacklights are now available, allowing communication with a central station to pass on the machine status, and models are also available that give more color control so different light patterns are possible. A more recent trend is to shrink the stacklight’s size, weight and cost enabling medium and smaller semi-automatic machines and equipment to use stacklights in applications where they’ve never been used before. For example, while large stacklights have been employed on big robotic systems, designers of smaller robotic machines have not considered using them due to their expense and size, but that’s no longer true. For instance, a small stacklight on a 3D printer saves time and aggravation since anyone in the area can see (and/or hear) the stacklight if the printer has stopped. Nothing riles an engineer, technician, scientist or pretty much anyone than losing time on a project because critical equipment was paused and nobody noticed.

Another use for smaller and lightweight stacklights is mounting it directly on top of the machine’s control box, which allows for a much easier and lower cost installation process than when placing it atop the machine itself. Why spend the effort to integrate the stacklight into the equipment’s wiring harness when it just leads back to the control box?

So, what can be expected of industrial audible and visual indication devices? Don’t expect much advancement with panel LEDs but keep your eye on panel alarms and stacklights as they keep taking advantage of electronic component innovation to offer more value and reliability while decreasing their size, weight and cost.