Hello all...
A number of neon signs were recently delivered to me in nonworking condition. All but one are driven by an Evertron 2610 power supply. Surprisingly enough, this power supply and sign combination were made in the US. Nearly all of these signs did continuous duty, shut off only by power outages.
The Evertron 2610 power supply is a pretty simple affair. It bases upon an IRF2153 driver IC and two IRF730 MOSFETs. The output from these is fed into a transformer that looks not unlike a TV flyback. As found, most of the signs would start and then shut down. Through some very interesting circumstances, I came to know that the power supplies would operate normally if powered from a generator. Protection functionality appears to be centered entirely in the IRF2153, though there is also a line fuse.
Every capacitor in the power supply was bad. None were visibly bloated or distressed...either the ESR had skyrocketed or the cap simply registered as open. Most were made by Meritek, a company I had never heard of before. With new caps, the first sign starts up and runs once again.
However, I'm wondering if the neon tube is worn out. The sign consists of three formed letters, each of which are supposed to be the same color, and one has a notably different (lighter) hue than the rest. Also noted are strange hissing noises from the tube (not the power supply), the ends of the tubing near the terminal points becoming very hot (sometimes to the point of making something start smoking) and "pulsing" from inside the tubing. Every now and then, the misbehavior will stop and things will be fine for a few seconds, just like a failing fluorescent tube.
Throughout all of this, the power supply remains cool and seemingly stable. It is rated for 5.5kV and 27mA current output, though I have nothing with which to safely test this.
I'm wondering if the neon tube has simply become weak or damaged at this point. All parts of the sign were made by divisions of Everbrite Electronics, and it sure seems "convenient" if they would all fail at roughly the same time.
How do neon tubes act when they fail?
William