CraffsiT)ar)&-Cor0er Edited by Chuck Larsen, Designee Director
ANTI-COLLISION STROBE Written by Weldon Unwell, EAA 30956 RR 1 Oshawa, Ontario L1H 7K4
Designed by Keith Harvey, EAA 180623 3 Callen Court Ajax, Ontario Canada L1S 3B1
Editor's Note: This fine article was first published in the Oshawa, Ontario, Canada Chapter 364 Newsletter. Chapter 364 is the host for the annual EAAC TECHNICAL SYMPOSIUM. SYMPOSIUM '82 is scheduled for October 15-17. For further information write: Oshawa Technical Symposium, Box 1340, Station B, Oshawa, Ontario, Canada L1J 6P8.
This little gem won't light the way to the moon, but it's small, inexpensive to build and reliable. The construction of this unit is not critical in any way and is within the capabilities of any homebuilder. A nice feature of this strobe is the low current drain which makes it feasible for use in aircraft without electrical systems. It could also be used as a portable unit if you have any need for such an application. This anti-collision strobe has been designed to operate without causing interference to other electrical equipment through the main battery supply of an aircraft. Low current requirements will also allow this strobe to operate from 6 volt hotshot type batteries, or electric fence types, in aircraft without electrical systems or as a portable warning signal for other applications. For best isolation, assemble the unit inside an aluminum box. with the VR regulator mounted by appropriate insulators to the box for heat sinking. Although the
power supply runs cool with 6 VDC sources, a lot of heat is generated with supplies of 12-24 VDC, and heat sinking will do much to add to the life of the regulator. Six volt operation can be performed without
the VR regulator and you can omit this if you want to run from such a supply. The instantaneous discharge current from C4 is quite potent, so be careful working around this part of the circuit. During assembly and testing, be sure to discharge this capacitor with a small resistor before you try poking wires and components. The power supply oscillator will "sing" at about 1500 hertz while running, and this will give you an indication that all is well. Build the unit in stages, testing as you go.Start with the DC power supply to the transformer Tl. The normal 110 volt primary becomes the secondary and you should be able to measure 300 volts or so AC at this point. Next, build the high
POWER SUPPLY C2
C3
D2
II
II
^ H
+H -
6-12 Volts Input
-H4
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