Electrical System and Circuit Protection
Electrical fault alarming and resetting on EFIS. When a circuit breaker pops, you may or may not know it. When the VP-X detects a fault, an alarm is shown on the EFIS and also may flash a master warning light and sound an audio alarm in the your headset.
Short circuit alarm
When a short circuit is detected, the VP-X opens the circuit and generates a fault on the EFIS. You can then leave the circuit open or reset it manually from the EFIS screen.
Current fault alarm
When a device draws no current when turned on, the VP-X opens the circuit and generates an alarm on the EFIS. You know right away if a landing light is burned out, an avionics fan has stopped working, or the boost pump is inoperative, for example. The feature can be turned on or off for each individual circuit. You can then leave the circuit open or reset it manually from the EFIS screen.
Configurable panel switches
The switches on your instrument panel for avionics, landing lights, boost pump, and other items are wired directly to the VP-X.
Two independent power busses in a single system. Read more a few sections down.
Over-voltage protection. Disconnects the active alternator if an over-voltage condition is detected.
Backup power for critical avionics. You can wire backup circuits for critical avionics so in the event of a failure there is an alternate power source.
Land light wig-wag with auto turn on & off. When you turn the landing lights on they are steady on the ground and then automatically pulse (wig-wag) while in the air. When you come in for landing, the lights are pulsing, but then remain steady below a specified airspeed. You can also set a desired warm-up time before the lights begin to pulse (typically for HID lights).
The VP-X drives the electric pitch and roll trim on your airplane based on inputs from external trim switches. It supports standard trim switches on the stick such as those on the Ray Allen, Tosten, or Infinity sticks (Do not buy the sticks with embedded relays).
Solid-state, no relays
The control circuitry is all solid-state, meaning there are no problematic mechanical relays to fail. For additional safety, each trim circuit has two solid-state control switches wired in series, and each switch is independently commanded (by two different command mechanisms) by the microprocessor.
Runaway trim protection and backup control
If your trim switch sticks or one of the switch wires shorts, you can stop the trim from running by pressing the opposite trim button. Holding the opposite button for three seconds will disable the trim switches. You can then control the trim from the soft keys on the EFIS as a backup.
The pitch trim motor runs more slowly at higher airspeeds, making the trim switch less sensitive. While at slower airspeeds (in the pattern, for example) the pitch trim motor runs at full speed. For example, you can set the pitch trim motor to run at 60% speed above 120 knots and 100% speed below 120 knots.
The VP-X connects to standard (up)-off-(down) flap switches, the flap motor, and optionally a flap position sensor. The flap switch can be located on the stick, throttle, or on the panel. The pilot and co-pilot switches are both wired directly to the VP-X.
Solid-state, no relays or black boxes
The control circuitry is all solid-state, meaning there are no problematic mechanical relays to fail. For additional protection, the flap circuit has two solid-state control switches wired in series, and each switch is independently commanded (by two different command mechanisms) by the microprocessor.
Motor run-on protection
Some flap motors, like the one used by Van’s aircraft, have no internal limit switches and will run continuously if not controlled properly. You can specify the maximum motor run time, after which the motor will shut off and an alert displayed on the EFIS.
Intermediate stops. With the optional flap position sensor, you can set the top and bottom limits as well as up to two intermediate flap position stops. Simply bump the flap switch down to go to the next down position, and bump it up to go all the way up. You can stop the flaps anywhere along the way by bumping the flap switch in the opposite direction.
Backup flap control
If your flap switch becomes inoperative, you can control the flaps from the EFIS screen.
Flap switch disable above a certain airspeed
The flap down switch is automatically disabled above a specified airspeed. The flap up switch works at all times. No mechanical airspeed switch is required.
Flap over-speed warning
The EFIS displays a flap over-speed warning on the screen if the flaps are down above a specified airspeed.
StarterAutomatic starter disable
If the engine in running, the starter circuit is disabled. This means you can install a starter switch on the stick or on the panel and not worry about hitting it accidentally during flight.
You see an annunciator on the EFIS whenever the starter contactor is closed. This is important as it can be difficult to detect a starter that is engaged once the engine is running.