Vertical Power solid state electrical systems for experimental aircraft

Introduction

Click for a larger view

In recent years, most of the avionics have evolved from older mechanical/analog systems to newer solid-state digital systems. Electronic Circuit Breakers (ECBs) are the next wave of technology to transform the cockpit.

Pilots have realized that the EFIS has many benefits over older steam gauges. Newer aircraft usually don’t have a vacuum pump and the avionics, trim, flaps, stall warning and a lot of other important components are now electrically powered. And as new features like runaway trim protection, flap controllers, landing light wig-wag modules, backup busses and dual alternators become more popular, wiring the aircraft has become very complex.

Vertical Power simplifies the electrical system by using electronic circuit breakers and microprocessors to remove the complexity and make wiring easier, yet provide many important features. And, you can install backup circuits for critical avionics.

Technology Overview
Vertical Power products are built using the latest technology to give you unprecedented functionality and safety features. Electronic circuit breakers give you a big advantage over older thermal breakers because they can do a lot more than just detect a circuit fault. ECBs are part of an integrated, microprocessor-controlled system that provides circuit protection, switching, and host of advanced and unique features.

Electronic circuit breakers, as part of a system, turn electrical devices on and off, manage contactors and alternators, run the trim and flap motors, handle short circuits, and watch for failed lights or other devices. About a hundred times per second, the ECBs monitor each power wire for faults and anomalies.

ECBs are a lot more “intelligent” than thermal breakers because they are controlled by a microprocessor and can be readily configured for each individual circuit. For example, you can set the circuit breaker value and whether or not to detect an open circuit right from the setup menus.

Each Electronic Circuit Breaker does the following:

•	On-off switching

•	Short circuit and over-current protection

•	Measures current draw through each circuit

•	Provides status to the microprocessor

•	With a little additional circuitry it provides dimming and soft-start capabilityEach 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 ECBs are housed in the Control Unit (the red box) which is mounted inside the cabin of the aircraft. The actual switching and circuit protection is done within the Control Unit. Any switches that you mount on your panel are wired directly to the Control Unit and simply tell the Control Unit what to turn on and off. For example, you could have a Landing Light switch that is wired to an input on the Control Unit. When you turn on the Landing Light switch it grounds an input pin on the Control Unit, which then tells the microprocessor to turn on both of the landing lights.

The "intelligence" can be used to enable features without adding complexity. For example, if you want to wig-wag (pulse) your landing lights, traditional wiring methods require you to buy a separate module, wire it and add a switch for it. That adds additional failure points, weight, and complexity. With ECBs, you simply configure the two landing lights to pulse and the function is performed by the microprocessor within the Control Unit. No additional complexity, modules, or connectors are needed. And if the EFIS or GPS is providing aircraft speed, the lights can automatically wig wag in the air but remain steady on the ground. Again, this new feature adds no weight or complexity to the aircraft.

More than a half-dozen patents have been filed covering various aspects of the system.

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.

Top 10 Reasons to Use Electronic Circuit Breakers (ECBs)

10	Cleans up your panel

9	Open circuit detection—alarms when you turn on a device and it does not draw any current. So you know, for instance, when your landing light burns out or your avionics fan is not operating correctly

8	You can monitor the current draw of each individual device, to assist with troubleshooting or if you're just curious

7	You get the best of both worlds—ECBs are remotely mounted yet you can view their status and reset a fault from the EFIS screen

6	When a breaker pops or fuse blows, you may or may not know it. When an ECB trips, you get an alarm warning.

5	Circuit breakers just pop, but ECBs can distinguish between a short circuit and an over-current fault. That’s important when you’re troubleshooting the problem

4	More features, yet easier wiring—just wire from the "red box" (which houses the ECBs) to the device you are powering. Lots of features without the black boxes, relays, bus bars, diodes, etc

3	Reduces build time. Experienced builders have told us the using ECBs can cut wiring time in half

2	Eliminate dozens of failure points. Each crimp connector, circuit breaker, relay, and black box is a potential failure point. ECBs are rated at 2 billion cycles

1	If you're installing a beautiful new EFIS, AOA, or GPS, why power it with 80-year old technology?

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

Partners
Below is a partial list of the products that Vertical Power integrates with.

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.

Check out our web forum

Product Feature Comparison
Quick Start Program
FAQs
Take a Virtual Flight Tour with Vertical Power
Just three minutes to be amazed.

Vertical Power now has a Video Gallery
Watch Vertical Power in action. Click here to view the videos.

Get Email Updates

Click here and read past newsletters in our Archive library.