JEH Ignition
 

Well,
I sent for 3 of the TIM6 kits and 3 "S" coils from Jerry Howell.
I got them in 4 days!

I quickly assembled one, and tested it on the bench.
It worked perfectly!

I then turned down a Ryobi flywheel (to 1-3/8), and installed the magnet.
I used the tiny magnet that Jerry supplies.
The Ryobi engine I tried it on was fresh off of a very used weed wacker.
I used a tie wrap to hold the hall sensor to the engine case, making it adjustable.

I put the sensor at about 10 degrees BTDC (eyeball), and choked till wet.
I turned on the switch, flipped the prop, and she fired right up, at a high idle.
When I went to full throttle, it ran rough, and had a "miss".
As I moved the sensor, the engine smoothed out, but still had a "miss", almost sounding too rich, although if I tried to lean it, it would just die.
I imagine that the dwell time is much too short with the small magnet (about 11 degrees).

The engine was not tested with the magneto first.

Here is what I got:

High- 6400 (rough running)
Low-1800-2100 (surging)
Prop- Pro Zinger 18x8

Again, this engine was not run on the stand prior to the ignition conversion.

This is what I plan to do:

Establish a baseline, with the magneto installed.
Change to the JEH Ignition system with tiny magnet.
Try different magnets and combinations of magnets to get the 64 degrees of dwell the formula says it needs.

Bottom line?
I think this system has serious potential, as long as the price stays as low as it is, and you like to tinker.

More later...

Joe Petro

JEH Ignition
 

Thats good to hear Joe, good job ;) So what does the whole ignition setup add as far as weight??? Battery; coil; electronics??
I assume some total weight is saved with the removal of the flywheel right??
Adam

JEH Ignition
 

do you have a way to measure current draw once you sort things out?

dave

JEH Ignition
 

Total weight savings are just over 6 ounces.
That is with a 700mah 4.8v pack.

I will measure current draw, once I get the dwell right.

You can see Jerry's site at:

http://www.jerry-howell.com/Ignition.html


Joe Petro

Dwell
 

There special hall sensors called latching sensors.
They will turn on with one pole of the magnet and turn off with the other. Just set your two magnets far enough apart to get the needed dwell.

JEH Ignition
 

Sounds like you have a classic case of not enough dwell, about the only "downfall" you can get into with this system. You will find you will need to install more than one magnet. I have gone over this thoroughly with Jerry. With the one magnet, you do not have the coil "turned on" long enough for it to charge properly at higher rpm's. Here is a picture of how to easily figure it out.


Good luck,
AV8TOR

JEH Ignition
 

Joe Petro...

See the "Scratch built ignitions???" page three for more info I posted about this subject.

Thanks,
AV8TOR

Me again for Joe Petro
 

I just did a search for "Scratch built ignitions???" and it didn't come up so you might have a hard time finding it.

Here is the address of the page:

http://www.rcuniverse.com/showthread...ber=3&forumid=

Have fun,
AV8TORR

Dwelling...
 

I bought some magnets from Radio Shack.
They are .200 dia. by .060 thick.
I turned the flywheel down to 1 inch, and drilled for two magnets.

This increased the dwell to about 51 degrees.
I have yet to try it on the stand.


TKG,
That latching sensor sounds like a plan!
I could not find anything in my electronics catalogs, though.

Do you have a number, or a series for these?


Thanks,

Joe Petro

hall sensor
 

Try digi-key look under sensors.

RE: hall sensor
 

Hey Joe I plan on ordering TIM 6 kit & PE coil from JEH tomorrow.Will this trigger properly with points as I don't mind using them to simplify everything.I have a Q35 W/points and am trying to shed weight.Also what do you use to cut down your flywheels as I want to use it just as a hub to strengthen area between threads and hub in case of crash.Thanks[&:]

RE: hall sensor
 

Rambo,
I would imagine that you could use the points instead of the hall sensor. I would keep the capacitor, though. There might be more info on Jerry's site about this.
As for turning down the flywheels, I use the end of a Ryobi crankshaft, chucked in the lathe, with the flywheel bolted to it.

I have been very busy with work, and have not had time to do much more with the JH ignition, but I did build my own CNC machine to cut parts out with.
You can see it at
[link=http://www.ibuyrc.com/7th.wmv]CNC Machine Video[/link]

Good luck,

Joe

RE: JEH Ignition
 

Joe

I have a Poulan 42cc I got out of a barely used chain saw. The engines flywheel is part of the case and not on the engine itself. I need to use an electronic ignition for it. I am tight of funds and cannot afford the CH ignition right now. Do you this this JEH ignition might work on my Poulan 42.:eek:

Thanks

RE: JEH Ignition
 

Sure, it will work fine. Just be sure you set it up correctly. See my drawing/explanation about dwell above. On a 42cc engine, be careful about kickback when starting with this system, as it has no automatic retard. But other than that it will work fine.

The only problem is that by the time you buy the system and the coil, you aren't too far off from being able to buy the basic CH Electronic ignition system dollar wise.

Good luck,

AV8TOR

RE: JEH Ignition
 

Don,t forget about the neat system RC(Ralf) ignition Has...good price also!!! Capt,n said that

RE: JEH Ignition
 

Capt John

Who is RC Ignition? Do they have a web site. i am open to looking into all options.:D

Thanks

RE: JEH Ignition
 

Do a search ...type in rcignition....you should find a lot of his posts. He is a very smart man and can convert just about anything out there. Got to go...Good Luck Capt,n

RE: JEH Ignition
 

Guys I just ran up my Q35 equipped with JEHI system triggered with points and I'm very pleased.Not only Did I loose at least a pound in dead weight, (I was able to remove the 5 oz. tailweight) but also saw a nicer running engine.One prob. though the run time on 500mah. nicad 4.8v. is'nt long enough I suspect it's because the dwell is way to long>The timing led lite stays on for almost 260deg. with the points system excessively draining battery. Also top Rpm's are down from 6900 to 6400 w/18/10 MA classic but i think thats just timing. I set points at 17 as thats what the author of Quadra bible recomends but that may change with electronic ign.[&:]

RE: JEH Ignition
 

I built one of these systems and overall am pleased, especially the simplicity and cost. But, I have burned up two coils. Is there any way to install a small/small current fuse so that if the coil remains energized the fuse will blow? Any help would be appreciated.

Doug

RE: JEH Ignition
 

A different idea but you could use a "One-shot" trigger system for your pick up. That way there is only one impulse going to the ignition module whether the points or pickup is still energized or not. The dwell can be varied by the use of a R-C circuit (resistive-capacitive).

Enjoy,

Jim

RE: JEH Ignition
 

Jim.....I think that reply flew right over our heads! Can you post a circuit diagram showing more details. Thanks Captin...not so smart

RE: JEH Ignition
 

The trigger circuit will go into a latch chip as Terry has already said. But this circuit will become unlatched after a time delay governed by a R-C network. "Latches" are chips that can be bought at Radio shack. R-C networks are a combination of a resistor and a capacitor value that will give the proper "delay-off". When the resistor and capacitor are in "series", the capacitor will not conduct until it charges up. The resistor will vary the time required to charge the capactor. We should be able to find a acceptable time value versus the rpm of the engine? In other words, the "Latch-On" chip will be energized, but when the "R-C" circuit energizes, it will "Unlatch" the Tigger circuit. The chip packages usually have typical circuit diagrams on them. Radio Shack, at one time, had a logic circuit book with typical diagrams.

74HCT259 8-Bit Addressable Latch
16 Pin DIP $1.29 Catalog #: 276-2868
The RCA CD54/74HC259 and CD54/74HCT259 Addressable Latch features the low-power consumption associated with CMOS circuitry and has speeds comparable to low-power Schottky.
This latch has three active modes and one reset mode. When both Latch Enable (LE\) and Master Reset (MR\) inputs are low, (8-line Demultiplexer mode) the output of the addressed latch follows the Data input and all other outputs are forced low. When both MR\ and LE\ are high (Memory mode), all outputs are isolated from the Data input; ie, all latches hold the last data presented before the LE\ transition from low to high. A condition of LE\ low and MR\ high (Addressable Latch mode) allows the addressed latch's output to follow the data input;all other latches are unaffected. The Reset mode (all outputs low) results with LE\ is high and MR\ is low.


Jim

RE: JEH Ignition
 

Try this link http://www.rcuniverse.com/forum/sear...&author=RCIGN1
Good luck Capt,n

RE: JEH Ignition
 

I've been thinking, and one of the original questions raised was how to keep the coil from burning up and second question was how to vary the dwell time?

I mentioned the latch/reset circuit in an effort to prevent the circuit being energized for long periods and burning up the coil. The reset time was used as a means of adjusting the dwell time.

But I'm wondering, that in the person's system that was burning the coils up, was he running too much voltage to the coil? I remember that back in the good ole days, that the coil on a car was fed directly from the battery (12V) by the starter solenoid when starting but was powered through a resistor with just the ignition switch being on. There was a resistor in the line from the ignition switch that reduced the voltage down to about 8V. Also if you left the resistor out and left the ignition on with the engine not running, the coil was history in short order. At any rate, it would run the battery down eventually if you left the ignition on with the engine not running. In later years, I had a garden tractor without points but with a electronic trigger module. I left the ignition on one time for a week and it didn't bother anything. At the time, I was thinking that the points must have not been closed?

Enjoy,

Jim

RE: JEH Ignition
 

Hey, I llke to tinker as much as the next guy, but.....the CD circuits sold by myself and TKG use ONE sensor, there is NO dwell time, the circuit trigggers every time the magnet passes the sensor, and will run for hours on a 4.8 volt 500 MA battery..No calculating dwell, just a DG6852 sensor from Digi-Key and a magnet.,Set the timing at 28 BTDC and fly....The small coils sold for use with these circuits were made to be used with points from a 3 or 6 volt battery, not a CD ignition that puts around 300 volts into the coil....
TKG and I both had "blue light" specials, he sold 3 and I sold 2...These circuits, when used with a proper coil, will outlast the engine and won't burn out any coil, although the Modelectric coils with their weaker insulation don't last as long...We put about 300 volts into the coil....
I guess $50.00 is too high a price....How much do 3 coils cost ? :D