When a customer reports spooky sounds emanating from a panel box, a young engineer calls in a convalescing veteran engineer for assistance.
By Dan O’Brien, Contributing Writer
When I was hired as the outside sales engineer for Mallory Sonalert Products in 1994, I was told that they would ease me into the job of helping customers design in the company’s electronic audible alarm products.
However, shortly after I was hired, the resident applications engineer, who had been with the company for nearly 50 years, fell and had a serious leg fracture.I was quickly thrust into the black art of technical customer support and began fielding phone calls from customers needing assistance with various technical problems. A trial by fire, it was.
One day I took a call from a customer that told me its production night shift had been reporting weird sounds coming from somewhere inside the factory. Their investigation led them to a newly installed alarm in a control panel — it was emitting strange noises even though the cabinet was supposed to be turned off.
(Insert spooky music here.)
An electrical technician who was called in found that even though the controller was powered down, there was a residual low AC voltage still on the line. Because the electronic audible alarm required only milli-amps of current to activate, this residual voltage was enough to make the alarm make a low scratchy sound. The day shift did not notice the sound due to the higher noise level during the day.
The customer reported that they followed up with the controller manufacturer who reported that this phenomenon did happen with some controllers, but they did not offer a solution.
My first thought was to use a large resistor in parallel with the alarm to shunt the current, but the customer did not have any large resistors on hand. They also didn’t like the idea very much because when the alarm was activated the resistor would also see full power and could potentially become very hot.
It was then that I thought to make a call to our convalescing applications engineer to see if he had run into this before.
“Sure,” he said, “I get calls about this all the time.”
“What do you recommend?” I asked.
“Tell them to use a low wattage light bulb in parallel with the alarm, and go ahead and mount the light on the panel next to the alarm. This will shunt the current from the leaky controller, but it won’t actually light up enough to be noticeable when the room lights are on. As an added bonus,” he pointed out, “When full power is applied to the alarm, the light will also fully light up providing a visual indication as well as an audible one.”
This solved the customer’s problem, and it taught me that when helping a customer, you should think outside the box and try to provide solutions that give customers more value than they expected with their original design concept.
Dan O’Brien graduated from Purdue University with a BSEE and MBA, and he worked in engineering and applications engineering positions for over a decade. In 1994, he moved over to the dark side of technical sales and is currently VP of Sales & Marketing at Mallory Sonalert Products, Inc.
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