I have a malfunctioning Aeroleds Pulsar NS nav/strobe and wonder if anyone in the VAF world has seen like symptoms. I bought the lights 1.03 warranty lifetimes ago, but first flight didn?t happen until 0.96 of the warranty had run. Want to assess whether appealing to Aeroleds is worth pursuing. Yes, I severely misunderestimated how long the last 10% would take, but jeez, just 10.6 hours on the airframe and I?m looking at shelling out half an AMU for a new nav/strobe?
THE SYMPTOMS:
Port side (red) LED is steady and bright, but strobe is irregular. For two or three cycles, the triple flash is markedly weaker than its brother strobe on the starboard wing (or the Suntail in the back for that matter), with the white LEDs? staying weakly illuminated until the next weak flash. Then the white LED?s go completely dark for a cycle, then the next cycle is a fully bright triple flash with the LEDs going full off. Then weak cycles start again?wash, rinse, and repeat.
Bad connections, especially grounds, are the usual issues according to Aeroleds? website. But I switched port for starboard: The green nav/strobe performed normally whether plugged into the port- or starboard-side connectors at the wing tips; whereas the red nav/strobe misbehaves on the starboard-side, just as it does to port.
On the plane, the two wingtip nav/strobes and taillight/strobe have their synch wires interconnected. But the green nav/strobe stays in synch with the Suntail when it?s hooked up to either side. Given the uneven flash pattern on both sides, it?s hard to say whether the red nav/strobe is in synch or not.
Moreover, the red nav/strobe exhibits the same weak flash, no flash, normal flash cycling behavior on the bench, its bare wires connected to a +12.5V dialed up on a power supply. For grins, I ?scoped the synch wire on the bench set up just to see what it looks like.
For a normal, fully bright flash, the pin starts at 7.4 V DC, then a negative-going, 30-ms pulse down to about 0.5 V occurs and recovers to about 6.6 V for about 35 ms. Then a series of three, positive-going (to 7.4 V), 10-ms pulses occur with an 80-ms period. Finally, at 335 ms from the negative-going edge of the first deep pulse, the voltage steps back up to 7.4 V and stays there for another 940 ms, then the whole cycle repeats.
When the strobe is flashing weakly, the series of 3 10-ms pulses are distorted. After the first pulse goes up to 7.4 V, it stays there past 10-ms, sometimes starting to decay with RC-like behavior. It may or may not get back down to 6.6 V before the second pulse pushes the voltage back up to 7.4. Similar things happen between the 2nd and 3rd pulses, and between the 3rd pulse and the final step back up to 7.4 V, which evidently does not turn off the current going through the white LEDs as they remain dim-ish-ly lit.
On the bench or in the aircraft, the sickly strobe will sometimes generate normal flashes when first powered on for several minutes, then weak flashing behavior begins. Sometimes, the weak flashing behavior begins at power up, and after several minutes a period of normal flashing begins. When I first observed weak flashing becoming normal, I thought maybe the unit had to warm up or something. But then good flashes followed by bad was observed. I don?t have a TC or IR camera to be sure, but the base plate of the unit seems to run hotter when misbehaving.
My guess is some temperature sensitive flaw in the PCB or a component is the culprit. But it?s not predictable what state the system will be in at start up. If it?s good at the start, or becomes good after weakly flashing for a while, it will go from good to bad and back again without, so far, any discernible cause.
THE SYMPTOMS:
Port side (red) LED is steady and bright, but strobe is irregular. For two or three cycles, the triple flash is markedly weaker than its brother strobe on the starboard wing (or the Suntail in the back for that matter), with the white LEDs? staying weakly illuminated until the next weak flash. Then the white LED?s go completely dark for a cycle, then the next cycle is a fully bright triple flash with the LEDs going full off. Then weak cycles start again?wash, rinse, and repeat.
Bad connections, especially grounds, are the usual issues according to Aeroleds? website. But I switched port for starboard: The green nav/strobe performed normally whether plugged into the port- or starboard-side connectors at the wing tips; whereas the red nav/strobe misbehaves on the starboard-side, just as it does to port.
On the plane, the two wingtip nav/strobes and taillight/strobe have their synch wires interconnected. But the green nav/strobe stays in synch with the Suntail when it?s hooked up to either side. Given the uneven flash pattern on both sides, it?s hard to say whether the red nav/strobe is in synch or not.
Moreover, the red nav/strobe exhibits the same weak flash, no flash, normal flash cycling behavior on the bench, its bare wires connected to a +12.5V dialed up on a power supply. For grins, I ?scoped the synch wire on the bench set up just to see what it looks like.
For a normal, fully bright flash, the pin starts at 7.4 V DC, then a negative-going, 30-ms pulse down to about 0.5 V occurs and recovers to about 6.6 V for about 35 ms. Then a series of three, positive-going (to 7.4 V), 10-ms pulses occur with an 80-ms period. Finally, at 335 ms from the negative-going edge of the first deep pulse, the voltage steps back up to 7.4 V and stays there for another 940 ms, then the whole cycle repeats.
When the strobe is flashing weakly, the series of 3 10-ms pulses are distorted. After the first pulse goes up to 7.4 V, it stays there past 10-ms, sometimes starting to decay with RC-like behavior. It may or may not get back down to 6.6 V before the second pulse pushes the voltage back up to 7.4. Similar things happen between the 2nd and 3rd pulses, and between the 3rd pulse and the final step back up to 7.4 V, which evidently does not turn off the current going through the white LEDs as they remain dim-ish-ly lit.
On the bench or in the aircraft, the sickly strobe will sometimes generate normal flashes when first powered on for several minutes, then weak flashing behavior begins. Sometimes, the weak flashing behavior begins at power up, and after several minutes a period of normal flashing begins. When I first observed weak flashing becoming normal, I thought maybe the unit had to warm up or something. But then good flashes followed by bad was observed. I don?t have a TC or IR camera to be sure, but the base plate of the unit seems to run hotter when misbehaving.
My guess is some temperature sensitive flaw in the PCB or a component is the culprit. But it?s not predictable what state the system will be in at start up. If it?s good at the start, or becomes good after weakly flashing for a while, it will go from good to bad and back again without, so far, any discernible cause.