Warning Circuit

[spg_76013]

Hi All -

 

FYI the attached file shows a slight tweak I made to the original Rutan warning circuit:

- a green 'gear down' lamp was added which is ON anytime gear is down

- the canopy lamp is ON anytime the canopy is unlocked

 

The circuit retains the original features -

- red gear lamp ON & Warning Horn ON when: canopy locked + gear up + throttle retarded

- gear/throttle warning horn defeat switch

- canopy lamp ON & Warning Horn ON when: canopy unlocked + throttle advanced

 

I've also got a wiring diagram for my entire VariEze (basic panel + alternator + starter) if anyone is interested.

 

Regards,

 

SPG1

Arlington, Tx

warning.pdf

[Ghost]

SPG,

 

Your Warning Lights diagram is exactly what I was looking for. I just installed a B&C Starter and Alternator on my VariEZe project. I also re-configured my panel.

 

I am interested in comparing notes, can you e-mail me a copy of your wiring diagrams?

I am interested in seeing how you mounted your Buses.

 

Ghost

[Hercpilot]

SPG,

I would like to see all of your electrical stuff also! I am starting to wire my varieze. I have a lightweight starter and alternator also!

 

Hercpilot

[spg_76013]

Hi All -

 

Attached is my wiring diagram for my basic-panel VariEze. The diagram isn't pretty, but it is compete. It is amazing how many wires are needed!

 

This diagram uses the warning circuit which I posted previously, and I also added a red fuel lamp, wired to go on whenever the fuel handle is UP, and This plane is wired with a master (battery) and starter relays. It also includes the B&C alternator diagram, along with the OverVoltage regulator (with an amber ALT overvoltage light on the panel.) It also includes a few extra wires run fore-aft for future enhancements.

 

I've run 17 wires to the aft/starboard firewall, and included a diagram for those as well. Only one wire, the heavy 2-gauge starter leads runs along the port side in my plane, going from the battery relay to the starter.

 

The use of colors, dashes and thickness doesn't mean anything other than to help follow the wire. Ideally, I should call out wire gage, which wires are shielded, etc.

 

I'd be happy to send anyone the powerpoint version of this, so you can modify to suit your needs.

 

Regards,

 

Sean Gillen

Arlington, Tx

fwd.pdf

aft.pdf

[Hercpilot]

SPG,

Thanks alot! Do you have any pics of your installation?

 

Hercpilot

[spg_76013]

Hi -

 

Here are some old pictures (not quite 100% complete wiring) from months ago, but they will give you the general layout. I've since added the amber alternator over-voltage lamp, and a 'reserve fuel' lamp to the panel. Once I start taxi tests (later this month), I'll shrink wrap or tape up all the wiring bundles securing. Right now, I just have them zip-tied to plastics wire anchors floxed to the sidewalls (great little things-- I used over 20 of them). While not a pretty layout, it works. I hope to have first flight by the end of the summer if all goes well.

 

Regards,

 

SPG1

[spg_76013]

Hi All -

 

Attached is a revised warning circuit table I've developed/implemented into my VariEze, along with the wiring diagram which produces those results. Comments welcome. (And if any electrical guru's out there know can figure a simpler way to get the desired table, please let me know!).

 

Thanks,

 

Sean Gillen

Arlington, Tx

WarningCircuitNew.pdf

[Waiter]

SPG_76013:

 

DO NOT APPLY POWER -

 

Take a close look at your photos - Your Rudder cable is laying across the terminals of the capacitor.

 

Waiter

[argoldman]

SPG,

 

You also might want to take a look at all of your crimps. My concern is with the strain relief that you have, especially in the small wires. My fear is that vibration may separate those wires. The extra plastic on the crimped terminal is designed to crimp around the exiting wire giving some strain relief and rigidity. In many of the terminals, it looks like this is not the case, If your wire is too small for the plastic part of the terminal, you can use heat shrink tubing to achieve a good result (use the right size stuff). It's hard to tell in the photo, but if it were mine, I would check every crimped joint in the joint.

[spg_76013]

Waiter: Thanks for the alert, but my rudder cables are not yet hooked up.. they were just temporarily tie-wrapped. I'm still a few months away from first flight. I should have gotten them out of the way before I took that picture. It might explain a popped ALT circuit breaker I got last week on engine start.

 

Rich: Thanks for your alert, I will examine all my crimps. It looks like I used the wrong size and/or type of terminal on at least a few of those in the pictures. I will scrub all terminals both there and in the nose asap.

 

This forum is GREAT - thanks for extra pairs of eyes.

 

SPG1

[schmeddz]

I'm just happy to see you using terminal busses for everything. Properly crimped terminals are kindof important as well. I've lost track of how many experimental airplanes I've rewired in the past that didn't have any TB's anywhere. You're troubleshooting will be mucho simplified when you get going and if you have any problems.

Not having TB's at all is rampant in flying airplanes. I'm guessing that wasn't going to be the final ieteration of your rudder cable. !

Have fun and happy electrons!

[schmeddz]

That cable that comes thru the upper right side of the instrument panel is frayed around the loop. The one that's connected to the bar that's attached to the blue knob. (I'm still trying to figure out what the function of that knob is?)

Another thing about wires on the right side of the fuselage that are underneath the elevator rod is just a bad place. I've had two airplanes that had the wires put there and if they got loose they always rubbed against the elevator pushrod. The wire bundle hold downs glued to the side are a good idea if thats where you want to keep that wiring.

[spg_76013]

That cable that comes thru the upper right side of the instrument panel is frayed around the loop. The one that's connected to the bar that's attached to the blue knob. (I'm still trying to figure out what the function of that knob is?)

Another thing about wires on the right side of the fuselage that are underneath the elevator rod is just a bad place. I've had two airplanes that had the wires put there and if they got loose they always rubbed against the elevator pushrod. The wire bundle hold downs glued to the side are a good idea if thats where you want to keep that wiring.

Thanks again for the input.

 

The steel cable mentioned (linked to the blue knob) is the pitch trim (ala original VariEze plans). A few strands of the cable are frayed outside at the very end of the cable, but they are outside/past the collar. I'll snip them off.

 

Wiring bundles: your reply brings up an interesting point: I worked all the wiring details in before finishing up the canard paint job, so I never thought about potential conflicts between the wire bundles and the canard pushrods. I will do a test fit asap to see if I have any problems there. Also, I haven't done this yet, but I'm planning on building a lightweight snap-on/off cover (just a 2-ply BID layup) to cover up/protect all the wires on the right and left side of the fuselage which are anywhere near wandering feet and the elevator pushrod.

 

Thanks,

 

SPG1

[Ghost]

SPG,

 

I used your technique for mounting my regulator and capacitor, thank you for the idea. B&C said id should be mounted on the opposite side of the firewall, however like you, I am confident this will work.

 

It appears you’re also using a B&C Specialty 200G alternator. I have a have a question for you on how it works for you on your panel. I followed the instructions, and they indicate that the light turns on when the system isn’t charging. My light turns off when I flip the switch with the engine off, thus not generating power, I think the light should remain on.

 

Ghost

[spg_76013]

Ghost-

 

I first mounted the regulator/capacitor in the hell-hole, but just did not like how it ended up... many fuel lines around lots of hard-to-reach electrical connections. So I moved it to the starboard/aft center-section spar location.

By design, the regulator will get hottest when the engine is at idle. I have a digital thermometer which I plan to temporarily affix to the regulator base when I start taxi tests, just to make sure it doesn't get too hot and start melting my center-section spar. Note I have a 1/2-inch standoff floxed to the spar, and I might put mount an additional aluminum heat shield/radiator to the regulator just to vent off more heat. If it is still too hot then, I might add a cooling fan and/or supplemental mini NACA inlet scoop on the bottom cowl to direct some air to the regulator. Hopefully, though, there won't be any issue. I should be starting those tests next month.

 

Check diagram PM_OV504-500_RevE.pdf, available from the B&C website... if both switches are on, then NO (the ALT supply current) is connected to COM, and NC (the lamp) is open. When the ALT switch is off, or the over-voltage module is tripped, the lamp will illuminate. There is no mention of the lamp coming on when the Alt is not charging. Seems like a modification is in order: if the ALT is not charging, we'd sure like to know about it. As designed, this circuit doesn't appear to do that. I'll see if I can figure out a simple, safe mod to do that.

 

SPG1

[raiki]

Hi all, thought I just give a quick dummies guide to this B&C circuit.

 

First off some relay terminology. COM stands for Common terminal, NO stands for normally open, NC stands for Normally closed. What this means is that if there is no power applied to the relay coil, the COM terminal is linked to the NC terminal. When power is applied the NC is disconnected and then the NO is connected to COM.

 

Ok, now that's under control lets look at the circuit. In the normal dead state, nothing is powered so no lights illuminate. Once you hit the master switch the the warning light is displayed because the relay is not powered. Your 'ALTERNATOR' switch applies power to the relays coil. This turns off the warning light and connects the regulator to the bus to charge your battery.

 

Some reasons why I think this circuit is absolutely pointless. Number one, go to your aircraft, turn the master on and the alternator on. The lamp goes out showing all is ok, except your engine is not turning and your battery is not charging. Great.

 

Now start your aircraft, nothing changes. The whole idea of test equipment is to see a change at initial power up so you know it will not give a false reading.

 

Now lets consider the fact your engine is running but your alternator is open circuit. There is no charging action, but your 12V bus is holding the relay on so the light is not illuminating. If the 12V drops to a point that the relay drops out, then the lamp will illuminate but be dim from the low volts.

 

The only useful part is if the crowbar over voltage trips the 2A breaker. Then the light will come on. I would suggest this is not the most common failure mode of alternators.

 

Now lets consider the 10-15A CB trips, but the 2A does not. The warning lamp will not illuminate regardless of any other condition. Great.

 

If you have this circuit in your aircraft I would label the lamp something like "Alternator Switch Off/Over Voltage". That's all it's good for.

 

Now I don't mean to bag B&C, because this is exactly how they say it works in the diagram. If my aircraft ever gets to the point of having an electrical system, this circuit will not be included.

 

Ideally you want an Ammeter in the charging line with the 10-15A breaker. If it is showing positive charge then all is good. Any fault that causes the alternator to not produce current with cause the ammeter to read 0 or negative.

 

I think a better solution would be to use a shunt across an op amp comparator that switches a lamp off at a specific voltage (generated by current flow in the shunt). Even using an LM3914 LED bar graph driver across a shunt would be pretty cool, but there are issues using a 3914 with a floating ground. Both pretty cheap reliable systems.

 

Some food for thought.

[Ghost]

SPG,

 

Thanks to your help, I figure out how to load photos again. As mentioned earlier, I used your technique to mount my Voltage regulator and capacitor. I fluxed in the studs, then covered them with 2 layers of glass.

 

I thought you might be interested in seeing how it turned out.

 

Ghost

[spg_76013]

Ghost-

 

You might consider putting some sort of standoff and/or radiator to keep the regulator from directly contacting from the center-section spar. I recall reading test data (from B&Cs website) on the regulator which states that it can get quite hot -- particularly while idling -- somewhere above 140 deg F.

 

Nice panel! I'm jealous.

 

SPG1

[Ghost]

SPG,

 

Point well taken on the cooling issue; it was a primary consideration during the installation. Although I have to admit I was more concerned with the regulator over heating due to its proximity to the engine, I didn’t give any consideration to the regulator its self heating up and possibly damaging the spar.

 

You can’t really tell from the photo, but there is an almost ¼ inch gap between the voltage regulator and the spar.

 

The method I used will allow me to add a couple of washers behind the regulator increasing the gap and the cooling, not to mention protecting the spar from the hot regulator.

 

Thanks to your input, I may consider adhering a strip of adhesive backed heat barrier material between the regulator and the spar, for that added layer of protection, if I can find a thin one. If the H/B material is too thick it will defeat the purpose of having the gap behind the regulator.

 

What can I say, Experimentation…..

 

Ghost

[argoldman]

does the regulator have to be grounded

 

You might also want to contact B&C about heat rejection. If the heat sink on the item also uses its base bolted to a metal firewall, by eliminating this, you might have an overheating situation. Perhaps a heat sink on the back with standoffs would be appropriate. Just a thought!

[brendanw]

Has anyone successfully connected the airspeed trigger on the RMI micro encoder to the 'SENSOR' lug on the Composite Design Nose Gear Retract Control System (Wright Nose Lift) circuit board to give a 'gear up' warning as the airspeed drops off?

 

Ref:

 

RMI_Micro_Encoder_Install.pdf, Page 20

 

RGnoseP4RC.pdf

 

I believe I can use a digital relay (Digikey LCA710) to trip the alarm, but I havent done any testing yet.

RMI_Micro_Encoder_Install.pdf

RGnoseP4RC.pdf

[TMann]

Try this:

http://www.maddyhome.com/canardpages/pages/alwick/index_files/Page575.htm

[BlairCM]

Hello there, may I ask you which circuit do you wired? Thanks.