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3.0 ELECTRICAL SYSTEM
3.1. Engine Electrical and Shutoff Electronics
The QUADROVER's main electrical power supply is a Power-Sonic PSH-1280F2-FR (UL94 V-0 flame
retardant) 12 volt 8.5 amp-hour lead-acid battery. This battery provides power to:
Propeller Control Board
Three servos (throttle, left and right brakes)
Four solenoid-controlled valves (two flow-cutoff valves and two flow-reverse valves)
The QUADROVER's hydraulic system also generates significant heat. This hydraulic pump is fitted with a
140° F (60° C) shutoff sensor. If the hydraulic oil exceeds this temperature, a thermal switch will ground
the engine's spark plug, causing the engine to shut off. The hydraulic reservoir is also equipped with a
visual sensor (no electrical connection) to show approximate temperature of the hydraulic oil.
3.2. Propeller Control Board Electronics
Since the various controls for the QUADROVER would be difficult to control manually, a Propeller Control
Board (Parallax stock #28205) is included to properly operate the QUADROVER. Before programming the
Propeller Control Board, download the example code from the QUADROVER product page at
www.parallax.com and carefully read through and follow the included documentation. It is especially
important that proper calibration is performed and all safety guidelines are followed.
The Propeller Control Board includes the following features:
Propeller P8X32A-Q44 Microcontroller
64 KB EEPROM (32 KB used for program storage)
Tachometer input
(8) N-Channel MOSFET driven output ports (4 used by the QUADROVER)
(8) servo output ports (3 used by the QUADROVER)
(12) auxiliary I/O connections with 10KΩ series protection resistors
Three-position power switch (on, Propeller on and servos off, off)
Mounting locations for the following Parallax sensors (not included):
-
GPS Receiver (#28146)
-
Hitachi H48C 3-Axis Accelerometer (#28026)
-
Hitachi HM55B Compass Module (#29123)
3.3. Ground Isolation
The Propeller Control Board's electrical ground is isolated from the chassis ground to reduce the
likelihood of damage in the event of an electrical short. The QUADROVER's solenoids are connected
between the positive battery terminal and N-channel MOSFETs. If the negative terminal of a solenoid is
accidentally connected to an electrical ground, the solenoid will activate. If modifications are performed
that require the Propeller Control Board's electrical ground be connected to the chassis ground, extra
precautions should be taken to ensure that the solenoids do not make electrical contact with the Propeller
Control Board through any chassis ground.
Copyright © Parallax Inc.
Propeller QUADROVER Robot (#28195)
v1.3 7/8/2008 Page 6 of 16
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