Extended Data Fig. 8: Schematic of the FlyVac apparatus.
From: No evidence for magnetic field effects on the behaviour of Drosophila
The currents in the coils were controlled by an external computer (1) via two data acquisition (DAQ) cards. The first (National Instruments, USB- 9263) connected the computer to the power supplies (2) (BOP 50-4M, Kepco Inc.) and controlled the magnitudes of the currents in the coils. The second (National Instruments USB-6051) controlled the switching box (3) responsible for the directions of the currents (parallel or antiparallel) through the windings of each coil (4). In the schematic, most of the 12 coils were omitted for clarity. A picture of the chamber and the coils is available in Schwarze et al. 29 A MATLAB script controlled the two DAQ cards (a) to provide an analogue output to the power supply and (b) to switch the direction of the currents via a digital output. Other components (described above): vacuum pump (5), buffer tank (6), solenoid valve (7), FlyVac apparatus (8), relay (9), and a laptop computer (10) that controlled the valve, sensors (11) and video camera (12). One LED plate (13) illuminated the tubes; the other (14) provided an infrared background for the video camera. Components 7–14 were placed on a table in the middle of the coils; components 5 and 6 were as placed as far as possible away from the coils.
