w8ye

My Feedback: (16)

Ralph, Terry,

This goes to show that its hard to beat a man doing his own job. Good work.

Enjoy,

Jim

jstanton

My Feedback: (14)

RCING1

Will your ignition work on a Poulan 40 cc chain saw engine OK? And if it will how much is the cost and does it come with directions. I need all the help I can get.

Thanks

Antique

My Feedback: (4)

Any ignition works on any chainsaw if properly set up...C&H sells kits..The C&H system comes in a small box and is completely shielded..I can't compete, except on Zenoah and other engines where I make a complete mount with the ignition inside.....Most of these are $150....

Rambo-RCU

My Feedback: (1)

Has anyone had much luck getting there JEHI system flying?I've had my Q35 running but not for long enough and lately not depenably enough.I replaced the 500Mah. 4.8 Volt Battery with 1300 Mah. 6 volt battery but it has'nt hepled that much .My dwell is now 75 FDeg. and 28 Deg. BTDC.static timing

Sky Viper

I'm dealing with a few "issues" with my first JEH.

I work in an electronics shop so I'm slightly fortunate to be able to do some "tests" durning lunch and break.

I'd like to offer a couple things to think about and maybe get w8ye to get more specific.

The design of the JEH TIM4/TIM6 is just like the schematic shown on 5 Bears site as the TIM4.
The basic difference is in the resistor values and HAL Part Number. Jerry also adds an LED for "timing" purposes. I.E. you can see it flash when the magnet passes the sensor.

The function of the circuit is basic.
The magnet turns the sensor on and passes a low (.5v) to a transistor (2N2907A) that turns on the TIP42C. The TIP42C acts sort of like a switch, applying battery voltage directly to the coil. While this voltage is applied, the coil builds a field. When the voltage turns off, the field collapses and causes an induced voltage to be applied to the secondary side of the coil. This collapse is so rapid that it created a very high voltage pulse that is passed to the spark plug. ZAP...Spark.

So, here are the issues to address:
1. Dwell.
As a function of time, the size of the hub holding the wheel is very important in this circuit.
Jerry gives some formula info but it's not going to cover the entire RPM range.
The longer the magnet is under the sensor, the longer the voltage is applied to the coil. Too long, and it burns up, too short and you don't get a hot spark.
Translation: if you set your hub at a diameter good for 5,000 rpm you can burn up your coil at idle and not run very well at higher rpms. If you set it for 2,000 rpm you'll preserve the coil but probably won't get any rpms out of it.
2. Coil damage:
The Modelectric PE coil that I have came with a paper that indicates that 2/1000 seconds (2 ms) is the optimum time for voltage to be applied to the coil.
To quote the paper: "Power applied to the primary winding longer than 2/1000 seconds does not produce a stronger spark. It does waste battery power and more importantly, it causes heating of the coil winding."
I also believe that the TIM6 may be applying too much voltage to the coil. The coil is designed for 3.6-6.0 volt applications. But running it at the lower voltage would certainly lower the current and prolong the life of the coil.
That said, I could not get my TIM3 to fire with 3 NMHi AA cells. (4.1 V)Using my bench power supply at 4.0 volts I got great spark. Converting it to a TIM6 (2 resistors) and powering it with a standard flight pack (4 AA NiCads) at 5.2 V produced spark with a vengence! So, I'll try to address the 3 cell issue another time or perhaps, by fixing issue 1.

So, here is my idea for fixing issue 1. and this is where I need help.
The idea would be to eliminate the change in dwell that happens when RPM changes, or when different hub designs are used. By the way, distance between the sensor and the magnet also effects dwell time.
To eliminate the change, we need to trigger that TIP42C for 2ms every time the magnet passes under the sensor. If we could use the magnet/hal sensor to trigger a single shot IC...the IC creates an output that is .5v or less for 2ms. This output, when applied to the existing 2907a base would provide a more precise/desired result.
Because the circuit would only fire once for each passing of the magnet, it would not "stay fired" if the magnet stayed under the sensor and would not burn up the coil.

I'd bet it can be done with 1 IC and an R-C (resistor-capicitor) network.

Summary
We need a circuit with the following:
.5v input trigger.
Static High (5.2 V) output with a single 2ms .5v low for every trigger.


Tom

Antique

My Feedback: (4)

TKG and I will be watching..If you guys find an ignition circuit you can sell for about $15 that uses only one sensor and triggers a REAL coil be sure to let us know, we'll quit making ignitions and go fly for a while
Good luck........

Sky Viper

Well Ralph, I'm not sure what to say.
I've seen your posts and I'm not sure what your ignitions costs, what it looks like, or if I want it.
I've checked out your web site(s) at rcignition.net and rcignitions.com and I have yet to see an ignition shown or described.
I've e-mailed you about it and received empty and short tempered replies in return. I even called you yesterday; busy signal for 10 minutes, then an answering machine. No return call as yet.
Microsoft word will "Save As" html and there are a good many programs that are very easy to use that will upload the files to your empty web site. We can see you know how to type, so now you just need some good digital pictures.

So before you get short and snotty with us again, why don't you put your goods where we can see them and let us decide if it's worth a try.
Otherwise, go fly and rest assured that you and TKG are not the only ones smart enough to figure this out.

TKG (C&H ignitions?) sells a product for $120 and then I have to buy an engine mount ($15), and muffler($25). $160.
With JEH and wackerengines, I've spent $121.

Not a great savings, but it has potential.

Can you do better? And don't give me any crud about a "REAL" coil.

Tom

tkg

My Feedback: (1)

OK no name calling or finger pointing.
Basic fact the Timm 4 and 6 are not designed for high speed operation. Look at the engines that are on the JEH site. This ignition is for them and IT WORKS VERY GOOD when used as designed. You can make it run on a weedie with a little engineering, but often you exced its design specs. A few more parts and more $$ you can add a latching hall or even build the auto reset RC circuit. But again you are asking it to do something it isn't designed to do.
If you enjoy the challange of doing stuff like this and have the ability, way cool, but there are folks who can't. Thats where RC and CH come in we design, sell and make a living at, conversion kits that the average modeler can install on his weedie engine and convert it to a model engine. These kits are simple to install and are designed for this use.
By the way we got one of the two Blue light ignition kits back. It looked like somebody had used a 100w solider iron on it and it would not work any more, it took about an hour to repair it. Thats why no more blue lights
If cheap is your operating mode, fly it on the magneto using Carr or Wacker parts. There lots of these mag conversion flying and the owners are having a blast with their plane and engine. However if the "need for speed" rears its head we are here to "help" with your problem.
I had a article published about 8 years ago in High Flight about converting the Mac 28 and 32 engines. At that time there were almost no 30cc sized gassers, so the weedies made good $$sense. But even then I warned about have a $300 conversion, a CH kit and a tuned exhaust, in a $25 engine. Each to his own need and budget.
Lets have fun and get some flying in.

captinjohn

Sky Viper....I think if you do a search, you can find photos of the ignitin system you mentioned. I do not know why RCIGN does not have photos. I have one of his systems. It is in a small black box. I did peek inside. Looks well made. I could place a photo of it(with cover off) on this forum.....but I want his permission first. By the way, he has the best warrentee on his ignition systems also. I have to say, a person could save a lot of time and money just buying these systems ready to go. Take Care Capt,n

Sky Viper

In my thinking, the electronic ignition is not a need for speed thing.

I want the lighter weight and easier starting, but I don't want to lose any power.

C&H is not out of the question for me.
The web site is a little confusing (I'm simple minded) ).

TKG, Item 125 on your site ('bout time it's back up ) is less than item 98 (ryobi conversion) + item 4 (synchro spark).
Is 125 different? Single box rather than 2 modules?
Item 98 does not say that it includes the hub with the magnet...does it?

I have a short shaft Ryobi, proper mount, muffler and a wackerengines hub for flywheels; what will it cost me to buy an ignition that is synchro spark controled?
Discount for buying 2?

Is your machinist back on line?
Do you do paypal?

Thanks in advance,
Tom

Antique

My Feedback: (4)

All yours, TKG....Now that your site is back up...ABOUT TIME
(But be nice)
He's being nicer to you than he was to me

tkg

My Feedback: (1)

Its simple read the fine print
PN 125 is a Syncro Spark Single Cylinder igitions module for use with a 1/4x32 spark plug. For use in something like a Saito 180.
For a Weedie you would want PN 26 or 126 (same but with syncro). These are ONLY a complete ignition system.
PN 98 is a complete ignition conversion kit. ( missing a comma in the web site) it is an ignition system AND a prop hub, nut, washer, magnet, sensor and bracket.
You would need PN 98 with a Syncro Spark upgrade and a short shaft adapter ($5).Your Wacker flywheel adapter is not of any use here.
If you don't have a NEED for SPEED then you can retard the timing so that the power is the same as the mag you are running, that way you won't need the Syncro Spark. The Syncro DOES NOT ADD any power to a properly set up engine.[X(]

Sky Viper

Thanks, I noticed just before I came here today, that the paragraph before the "complete ignition" says that it is not complete. I guess the simple part of me bit on the word complete and expected that complete meant that is all that is needed. Do a lot of people buy it with out the magnet and sensor? Those 2 items would make complete.

So, items 126 + 103 is the same as 98 + 4 ? Is the 126 is a single module where as 98 and 4 are seperate?

Short shaft adapter? Is the magnet in the adapter or the hub?

And one other thing do you gents take Paypal? Visa?
Or just checks in the mail?

Tom

tkg

My Feedback: (1)

PN 26 and others are complete ignitions. Like it says they are for engine that are already set up for our ignition and all that the owner needs is the ignition cause something happened to the orginal one.
126+ 103 is same as 98+4 except 126 is a single unit and 98+ 4 is two parts
Magnet is in prophub, adapter is to mate prophub to the short shaft crankshaft
Also like it says under ordering we take Visa , MC and Discovery