Vertical Power solid state electrical systems for experimental aircraft

Technology Overview
The Vertical Power products are built using the latest technology to give you unprecedented functionality and safety features. The page describes some of the design details of the system.

The “red box” houses solid-state circuitry the provides total protection and management of the electrical system on your aircraft. It turns electrical devices on and off, manages contactors and alternators, runs the trim and flap motors, handles short circuits, and watches for overvoltage and under-voltage conditions. And much more. Its fault-tolerant design allows it to operate should certain sub-systems in the box fail or if other system components fail. Click on image for a larger view.

Data Integration
Using data from different systems like the GPS and engine monitor to affect control of electrical functions is a powerful concept. Combining information available on today's all-electric aircraft can lead to decreased pilot workload and increased safety. One and one equals three. EFIS systems do this today to simplify the scan and enhance positional awareness, and we've adopted a similar philosophy with electrical switching. The VP-200 takes full advantage of this integration, and the VP-100 and VP-50 to a lesser extent.

A few examples include:

•	Turning on electrical devices automatically as you go from one mode of flight to another. For example, turning on the boost pump and landing light as you transition from taxi to takeoff.

•	Automatically turning on the boost pump if the fuel pressure drops.

•	Checking that the aircraft is configured correctly for each mode of flight (for example, making sure your flaps, trim, and mag switch are in the right position for takeoff. Yes, you can use a checklist but there are reliability issues on the human side).

•	Decreasing the trim speed at higher airspeeds or based on flap position data.

•	Disabling the flap switch above a certain airspeed.

•	Turning on the landing lights when the traffic alarm goes off.

•	Turning off the landing light wig wag automatically below 70 knots.

•	Presenting checklists automatically right when you need them.

•	When device A is on then automatically turn on device B.

•	Disable the landing gear circuit below a certain airspeed.

•	When at full engine power during a go-around or missed approach, when you raise the flaps they go up at a slower speed.

•	Automatically turning off the air conditioning while the engine is at full power or shut off.

•	Electrical faults are tied in with the voice warning system.

Any of these in itself is not an overwhelming task. But you add them up and pretty soon you've built in a good margin for safety and simplified the task of managing the aircraft so you can focus on flying. These features are useful and practical for even basic VFR flights, and very helpful in high traffic areas, IFR conditions, or when flying in formation.

Reliability
The Vertical Power products are designed specifically to operate in an aircraft environment. That means they can take the voltage spikes, vibration, electronic noise, and temperature ranges found in a typical metal or composite experimental aircraft. Further, the products are designed so that if a failure does occur it is isolated and most likely will only affect a specific sub-system. In other words, it is designed to fail gracefully.

The following design points illustrate how these high-reliability goals have been implemented:

•	Any single box can fail or shut down and should not affect the other components. The major boxes are tied together with RS-422 fault-tolerant serial data lines rather than “hard lines.”

•	The power supply that controls the system’s digital avionics can operate from 4 volts – 32 volts, 40 volts for 1 second, and 60 volts for 100 milliseconds. This allows the system to operate normally during engine start and other events that cause voltage transients.

•	The VP-200 Duo system includes two Control Units for additional redundancy and support for dual independent busses.

•	Each connector pin is protected from static electricity and high-voltage transients.

•	The microprocessor in the Control Unit is isolated from the solid-state switches so that if the processor fails, the switches will most likely remain in their last commanded state. In other words, everything should stay as is.

•	If the Display Unit fails, the Control Unit(s) will continue to operate normally. They will remain in their last commanded state and the flaps and trim continue to operate, as well as the switch panel switches.

•	RTV silicone is used to support the larger components on the circuit board and protect them from vibration.

•	The system can still be shut off in the event of a processor failure by holding down the green power button for three seconds.

•	Built-in protection from failure of the position sensor power supply.

•	Only components designed to operate over a wide temperature range are used.

Compare the traditional panel and trim wiring scenarios with a solid-state implementation. The amount of wire used and the number of crimp connectors, mechanical switches, and mechanical relays goes way down.


-Old Way		-Vertical Power Way



Trim wiring	Panel Switches	Solid-state Control

And the home-run type of architecture (wiring goes to a central point) used successfully in other industries and commercial aerospace makes troubleshooting much easier.

Solid-State Circuit Control & Protection
The Control Unit uses the latest generation of solid-state switches which have been designed for the automotive industry and are appropriately adapted for an aviation application. Each solid-state switch (i.e. a single integrated circuit) does the following:

•	On-off switching

•	Short circuit protection

•	Measures current draw through that circuit

•	Provides status to the microprocessor

•	With a little additional circuitry it provides dimming and soft start capability

Each switch is rated for two billion operations, and this type of switch is in wide-spread use in the automotive, transportation, and marine industries.

The Control Unit also manages your entire electrical system. It provides over-voltage protection, under-voltage alerts, and individual circuit control for load shedding. It manages power to the alternator field, control of the battery contactor(s), cross-tie contactor, and starter contactor. And it provides power to the various avionics, motors, and sensors on your aircraft. The trim motor circuits are regulated to +12v and can drive the trim at various speeds. It can turn each device on individually, exactly as you configure it.

What’s wrong with the way we’ve been doing it for decades?
Compare the cars made in the sixties with the cars made today, and you’ll notice significant improvements in features, reliability and safety. Ask yourself if digital electronics are more prevalent now in cockpits than they were just five years ago. If you’re building an all-electric aircraft with a modern glass panel, why should your electrical system be based on decades-old technology? With that in mind, we’ve put together a short table to compare the Old Way with the Vertical Power Way:


	Old Way			Vertical Power Way


	User experience – 1965 automobile			User experience – modern luxury car

	LCD representations of analog gauges			Intelligent display of relevant information in context

	Cockpit management			Configurable control of repetitive functions with audio advisories so you can keep your head outside the cockpit

	New functionality requires rewire/install new boxes			Software update provides new features

	Multiple boxes for discrete functions			Functions integrated in same box via software

	Switches, wires, circuit breakers			LCD screen, microprocessor, solid-state switches

	Emergencies can overwhelm pilot			Pre-configured responses to emergencies

	Memory, checklists			Modes drive configurable system behavior

	Find checklists			Show checklists at right time

	Functions limited to that provided with each box			Settings configurable via set-up menus

	Time consuming to wire each discrete box and sensor			Run wires from Control Unit(s) to devices

	Call multiple vendors for support			Vertical Power integrates many functions

For additional information on Vertical Power products click on these links below


VP-50 Product Information	VP-100 Product Information	VP-200 Product Information

For more information
Please see the documentation page here for detailed manuals and drawings.

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