Richard Nakka's Experimental Rocketry Web Site

PHOTO 60 -- Flight C-12 : July 8, 1979

The parachute ejection triggering (PET) module used for Flight C-12. This was a very simple circuit consisting essentially of an air-speed switch, inertial (latching) switch, and a power supply (6 AA batteries). The purpose of the inertial switch was to provide for an "open circuit" condition prior to liftoff (as the air-speed switch was closed). Acceleration of the rocket during launch acted in conjunction with an inertial mass within the switch to "close" a micro-switch. A mechanical latch retained the switch in the closed position.
The white strip is a set of contact points which allowed for checkout of the system while the rocket was on the launch pad.

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