LAKAPIS Electronics

The electronics for LAKAPIS were a simple intervalometer based on a digital 555 circuit, designed by H. Scott McCann published in issue 5.1 of the Aerial Eye. The printed circuit board for the brains of LAKAPIS was designed in Osmond PCB (ps, pdf, osmond) in Mac OS X, printed on an HP Laserjet printer on transfer paper, transfered to a copper clad board, and etched with ferric chloride.

Filters were changed continuously, while the intervalometer fired the instrument. This resulted in poor exposure and focusing, the greatest problems with LAKAPIS flights. The new circuit design will detect the presence of a filter, stop the motor turning the filters, and fire a picture before starting the filter rotation again, probably based on the voltage comparison capabilities of the LM393 logic chip.