A Simple Strobe

Bob Hartunian

A Simple Strobe

I finished a partially built Zenith 701 STOL that had Aeroflash strobe power supplies mounted near wingtips with no accessibility provided. Sure enough, when plane was finished, one strobe didn’t work and I could not get into unit to fix. Decided to make my own strobes from simple parts.

You can buy a strobe unit intended for search/rescue purposes for $5 each ( https://www.quakekare.com/emergency-strobe-light-p-45?gclid=Cj0KCQiAkKnyBRDwARIsALtxe7j4z_xEZrBx0EVx1hRgzOYaXuZw3cOU_1aDBW7Ce4Vd5MDB_3ZtD04aAuKZEALw_wcB ). ( Figure 1).  Works from a 1.5 VDC D-Cell battery and pulses at one flash per second. The strobe bulb has all the circuitry built-in (Figure 2). All you need to provide for operation is the 1.5 VDC from ship’s power that requires a tiny step-down voltage regulator.

Amazon has miniature adjustable DC voltage regulators for $1.50 each. I bought a pack of 8 each for $12. Only needed one to power both strobes at wing tips. (  https://www.amazon.com/LM2596-Converter-3-0-40V-1-5-35V-Supply/dp/B01GJ0SC2C/ref=sr_1_20?crid=25YLYBVX9OES6&keywords=dc-dc+voltage+regulator&qid=1581957870&sprefix=DC-DC+Voltage%2Caps%2C210&sr=8-20  ) (Figure 3).
Mounted one regulator in cabin and ran a single 22 gage wire out to each wing tip. Output from the regulator is split between wires. I set the regulator adjustment to 1.6 VDC output to compensate for any voltage drop from wires.

The hardest part of the job was to adapt the strobe bulb to the existing wing tip light bracket (Figure 4). I cut away the sides of the bracket to allow the wider bulb to fit. Bonded the bulb to the bracket and soldered a wire for power and ground to the bulb. Used Bondo to fair in the bulb to bracket. Mounted the brackets back to the plane and turned on power to see each strobe flash every second. 

The strobe bulbs are smaller than a normal Aeroflash unit but you still get an actual strobe flash that would satisfy an Experimental anti-collision requirement. For the price of ~$12, I have strobes working at wing tips.

Bob Hartunian, EAA 529299

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