Superior switched Ignition/Starter system

A differend [better?] switched Ignition/Starter system

I've been thinking a long while (maybe too long) about how I wanted my ignitioin switch to work. After a lot of review, I think I may have taken a bit from everywhere to come up with a system that is superior. It's a hybrid of the old bat-switches with turn-key simplicity.

It uses two DPDT switches both are on - off - mom. They are $9 each from Spruce No. 11-00768.

Configured as:

--- Start ---
--- L HOT R ---
--- OFF ---

The down position for either left/right grounds that mag. Middle possition is ungrounded (hot) for either mag. Pulling both left and right together to the momentary up position grounds the right mag and simultaniously energizes the starting circuit. The starting circuit is in series so BOTH the left & right switches must be in the up position to energize the starter.

I also built a switch gaurd from two 1" pieces of 3/4" AL angle. It's dirt simple: To start, turn the master on and pull the switches up. You dont need to remember which mag has the impulse/retard or how that work. Why do I think this is better than a key switch?

1 - It lasts longer. Keys ware out; switches not nearly as much.
2 - I loose stuff (a lot), especially keys!
3 - It's safer, you have to pull two switches together to engage the starter. It would be hard to engage the starter by accident while doing a mag check.
4 - It's simpler (more basic). Installation has a couple more wires than a key system.
5 - It's cheaper ($18 vs. $52)

If you want a schematic or pictures of my installation, let me know. I just finished installing it and testing it. It works pretty well. I hope this generates some interest.

-Bruce

That is a cool idea. When I saw "Superior" in the title I thought it was somehow tied to their engine.

What I need is a system this simple for the Emag/Pmag. Since they need a power switch for each, I think I'm stuck needing either 4 bat switches or 2 bat switches plus the key switch.

You need "ON" in the middle... It's a bit pricier. But you can find On-On-Mom switches and use the same exact system.

-Bruce

Be sure you dont hook things up so as the 12v from the starting position can get into the mag--------------they dont like things like that.

And you dont need a center on as Bruce says----------

Mike

Mike S said:

Be sure you dont hook things up so as the 12v from the starting position can get into the mag--------------they dont like things like that.

And you dont need a center on as Bruce says----------

Mike

Click to expand...

! MUST ! be DPDT - Dual Pole - Dual Throw... That means internally there are two seperate switches that pull together. This keeps the 12v source away from the magneto current.

Somebody asked, so I drew up the diagram. It's based on a diagram for a show-of-sparks system I found on Bob Nuckoll's aeroelectric.com site. I did modify it (to wire the momentary-up in series and remove the shower of sparks aspects).



-Bruce

??????

Bruce, you quote me like there is something I said that you dont agree with, but I cant figure out what it is.

You are correct that the switchs MUST be Double Pole, although I am not sure if "Double throw" would be a correct designation for a three position switch, (I.E. 1, off 2, on 3, start) Perhaps that is known as a triple throw.

In your first post, you said this circut would require a switch configured as "on, on, mom"-------that is what I disagreeded with, and your own posting of the diagram DOSENT use an "on" position in the center.

The panel is labeled as "on" when the switch is centered, but in fact the switch is electricaly "Open", or off.

Also, the way you have it drawn, the right mag is grounded when in the start position,-------and the vertical line you show connecting the movable contacts should be a dash line, as it is now, you are using the same line as your wire designations, and someone could misinterpet that as refering to an electrical connection between poles 2 and 5, not the mechanical connection I think you ment to show.

I wish I knew how to do drawings like you did, would make things clearer than words do.

Mike

Actually, Bruce's initial post says he used on-off-momentary switches. The on-on-momentary was for the Emag/Pmag that I was asking about. Sorry to confuse the topic.

Labeling the middle position "on" makes sense to me. The mag is ungrounded and thus producing a spark. It follows the same logic as a key switch which is off-R-L-both-start.

Mike S said:

You are correct that the switchs MUST be Double Pole, although I am not sure if "Double throw" would be a correct designation for a three position switch, (I.E. 1, off 2, on 3, start) Perhaps that is known as a triple throw.

Click to expand...

Each position in which a connection is made is a "throw" for naming purposes. "Off" doesn't count as a throw, so they're DPDT switches. You can have both 2 and 3 position double throw switches, the difference being that the 3 position switch has a 'make no connections' position.

I've thought a bit about this now. When (not if) I install my pmag...

You dont have to worry about which mag is running impusle coupler/retard. Just turn them all on. All you need are two on-off (SPST) switch and a seperate guarded push-button for the starter. eezy-peezy

-Bruce

Mike S said:

Bruce, you quote me like there is something I said that you dont agree with, but I cant figure out what it is.
Mike

Click to expand...

Sorry Mike, the quote was to direct my answer... I agree completely! 12v for starter does not belong in the ignition system. I think others have stated this, but I'll re-state since you directed the inquiry at me -

The on-on-mom / pmag issue threw the thread for a loop. The on-on-mom switch is pretty much a half-baked idea for solving a basically simple problem for pmag installations. See my previous post. The solution I posted is DPDT and is for the bad-old grounded manetos only.

-Bruce

I use the system you guys are describing (from Bob's Aerloectric Connection) with one mag on the left and a Lightspeed on the right on my -6A. WORKS GREAT!!

Simple, reliable, safe and foolproof.
Greg

MAG Switches etc

For my RV-4 I kept it as simple and light as I could. I used two SPST toggle switches, one for each mag, and another SPST momentary toggle, with a guarded cover ('missile' switch - I hate that term), to energise the starter. This I copied from the CAC-25 Winjeel I used to fly (P&W 985). It is simple, no tangle of wires, and the momentary guarded starter switch is safe apart from when you want to use it. I dislike intensely key switches.

RV-4 VH-PIO
250hrs

Oops

Bruce, I just went back through the ENTIRE thread---------and figured out that you are the one who STARTED it. Duh.

In my orininal read---------I usually scan through threads to see if anything is usefull to me----------I missed you starting it, and thought the response mentioning the "on-on-mom" was a RESPONSE to the original post.

Haste has its place, but I guess here is not one of them, sorta like doing a pre-flight.

Sorry 'bout that.

Mike

epmags and p-Lead

I hate to see a good tread fade. I looked over the installation instructions for the pmag:

http://www.emagair.com/Installation.htm

They built it as a drop-in replacement for traditional mags. It has a groundable p-lead. So the origonal diagram I provided works great, if you're willing to run a p-lead. Although because you start on both epmags, remove the jumper between Pins 1 & 3 on the right switch.

If you dont want to run that second wire per epmag for p-lead, the two-switch + starter push-button would work just as well too.

-Bruce

I don't see any way you can use 2 switches to control 2 P/Emags. You need a switch for each p-lead and a switch for each power line. The power line could be switched with a pullable breaker, but I've read those breakers aren't rated for lots of use.

Control is needed independently over the p-lead and power line to:
1. Control the new Run Mode Starting Delay feature.
2. Set/check the timing.
3. Test the generator on the Pmag.

And who knows what future feature. Anybody that is planning the wiring for a P/Emag should read the full installation instructions. The Aeroelectric wiring diagram will limit the functionality.

Dave

You nead a fused +12v line that's runs (unswitched) directly off the master bus to both epmag units. Because the pmag is self-generating, you dont have to worry about single point of failure on that wire. Then you run the p-leads like it was a regular mag. same same.

-Bruce

This really works nicely!

I know this is an ancient thread, but now that I'm flying, I really love this simple ignition/starter switch... I found that my old schematic is gone, so I re-did it.

Schematic

Installation picture (above Exp-Bus) notice the placarding

I believe I used NKK S339T-RO from DigiKey $10.26, I found something similar on google... $5.15 each!

So... $150 for a key'd ignition that you will need to replace every 10 years... or $12-$25 for an intuitive switch pair that will last as long as the plane?

-Bruce

Follow up

Just a quick follow-up. I love this ignition/starter switch so much, I'm retro-fitting it to my RV-6 project.

It's really intuitive and so simple.

BruceMe said:

Just a quick follow-up. I love this ignition/starter switch so much, I'm retro-fitting it to my RV-6 project.

It's really intuitive and so simple.

Click to expand...

Can you start with mag only with this system?

I have stopped using EI on start because of a kick back if engine does not keep running after start. This happens sometimes if prime is not just right. This is very tough on starter ring if starter is not disengaged immediately.

Yes, it's wired for single mag start

The wiring in the diagram shows how it grounds the right mag (off) while in the start position. If you set up you EI on the left, just swap left/right.