Aircraft Vent Controller Board and Motor
This is a very compact linear actuator control board that drives the most compact linear actuator on the market, the Haydon Kerk 15000 series. It features the new ENHANCED mid-range core Microchip 16F series family, specifically the 16F1826 family. This new spin on the standard 14 bit core of PIC family adds 14 new instructions, a 16 level stack, context save on interrupt, and other “C” friendly features. It also offers 8 MIPS performance with an on-chip 32 MHZ clock, up to 14 KB of Flash program memory and 3KB of data memory. It also features the Extreme Low Power (XLP) Microchip features offered in other newer PIC microcontrollers.
Also the design uses the new National Semiconductor LMZ14201 integrated low noise switching regulator. It’s choice was dictated by extreme compact size requirements of the design AND the ultra low noise EMI performance of the National device. The device operates on standard 28 VDC aircraft power.
The Stepper motor of the linear actuator is driven by a pair of H-bridges consisting of the International Rectifier IRF7555 dual P-channel and IRF7530 dual N-channel devices in tiny SO-8 packages. The PCB is a 4 layer design with SMT devices on both sides.
The function of the circuit is to control the position of a small plastic vent damper that slides inside of the air tube itself to adjust the air flow to the passengers below it. It replaces the “hand twist” mechanical solutions currently in commercial aircraft.
