TKG,
Thanks for the explanation.
I knew that they measured before firing, but not how they did it.
As always, the most simple solution is the best.

That means NO large magnets.

TKG...I like how you explained that...so I bought it to the next page. Also I like the small magets you can get from radio shack. Capt,n

TKG, How large is large ? I'm using those 1/4" square super magnets, are these big enough, is two of them end to end too big ?

The clock is calibrated around a 3/16 magnet. Using a 3/8 wide magnet mean that you have to flip 2x as fast to retart the timing.
With a CDI ignition a bigger magnet does not make a hotter spark than a little one. We use a 1/8" cobalt magnet in our conversions

The RCEXL and the CH are exactly the same circuit. I have a RCExl circuit that was not working ,I striped it and drew a schematic same circuit as my older C&H.I guess Mr, XU has not seen my new circuit. I will have to send it to him. This is OK after 26 yers I am tired of building ignitions . This is why he has a good reliable Ignition . He says some one has cloned his ignition.Very funny. I have just received my new DL-50 just ran it on the test bench ,I am impressed.I am installing in a Bling. No the wings will not fail
BCCHI

Don't get tired of building ignitions, I still need/want good ignitions and to heck with all those UAV guys

i got some nicd battery's today.
grandad gave em to me today (christmas day after dinner) and said they were stuffed.
i looked them over and they are new casings but i wondered what the cells are like, i tested voltage from full and it read 11.2v (on my xmas multimeter hehe)
then i tested each individual cell and they are all over the place, some at the correct 1.26v (3 of them) and the others wary from 1.08 to 1.12v
if i charged the pack and get a proper 4 cells reading 1.26v then could i use them as a ignition pack?
they are 1300mah and my testing shows that they are in good condition.
all i need now is a peak charger for 4.8v and i'm set.

whay do you guys reckon?
shaun

trickle charge first to equalize the cells.

ok,
i'm charging them at 450ma and they are still in the 12v pack configeration.
i hotwired a charger from another 12v pack to charg this one.
shaun


edit, charges and they are now all reading 1.3v (prolly more charging to go but i don't want to overcharge yet untill i get a peak charger)

trickle charge is at 1/10th C. 0.5A probably is too much when individual cells have reached 100% charge, and the others still need some juice.
Wtch the cell temperatures. Fully charged voltage is 1.56V per cell.

i hope i ordered the right magnet[&:]
i ordered the 3/16 X 3/8 magnet and a hall switch to go with the CHRCEXL ignition.
is it the right magnet?
TGK said in a previous post that the clock is calibrated around a 3/16 magnet....is that diameter? and if so is the magnet i ordered 3/16 dia and 3/8 deep?

shaun

magnet length is hardly of influence to the magnetic field over the poles.
Important is the magnet quality. Rare earth magnets are best. Ferro magnets are to be avoided, unless they are high quality.

Both McMaster-Carr and MSC offer a large size selection of neodymium, rare earth, magnets. You can get a .250 diameter X .250 long but i would advise staying around the .157 diameter X .1 length. They run about $3-$4.00 each. If available, use the nickle plated. MSC does a shielded magnet but they are a little pricey. I've used both in different applications and the cheap ones are just as good. Another good reason to stay with the smaller magnets is balance. Those magnets don't weigh the same as the aluminum they're replacing.

bump

Well sense this thread got (bump) i will add this.just got done converting a mvvs 45 with a bad Vlach ignition and replace it with a Rcexl and had no problems at all just had to relocate the timing sensor to get it at 28 degrees BTDC and all is good.

I have the little 1/8" cobalts like Terry describes above in everything I have. They work great and like Al said, the lighter the better so you don't throw the balance off as much. CH builds an incredible CDI ignition unit; kinda like a Timex watch they just keep on a ticking.

These ignitions work very well and many people are selling them now under thier own brand name. Everyone is using them since they are so inexpensive.

I thought of one thing to add here,[sm=idea.gif] although most will not be interested, a few might. I am running both the CH and CHRcXL on my SuperTigre G51 converted to Gasoline. I am turning this little fellow over 15,000 on the ground and whatever it unloads to in the air without any misfire at all. This thing sounds just like it did on glow save for it's just a little louder on Gas. Yes, I am a racer, and also an experimenter. For some unknown reason I just love to hear engines scream. Point is these ignitions Bill and Terry make and sell will far exceed the rpm range of most gassers. I haven't yet found their limits rpm wise but it must be pretty high.

P.S. All of this is done using a 4.8 volt pack.[8D][8D]

A question for Herby 1

I've never run a Quadra, or used a CH ignition.
At work, we have a Quadra 150 with a CH Synchro Spark.
It's marked 12 Volt.

Is this normal, or something special?

Who is Herby 1, cause if you are referring to Ralph from RC Ignitions, he does not post here anymore, but quite possibly might be lurking.

Karol

Special custom unit for Quadra.

Thanks for the reply.

I guess I was looking at the older posts.

Hi,
A question for CH .
I have a old CH ignition which was used with OS 91 4T (methanol).
I have a new project and want to use it with a YS110 4T methanol.
Form my memory YS don''t like much advance. In your early doc. (15 ears ago) was wright ~20-24 deg max advance for mechanical CDI and idle point fire on TDC.
How can i use your External Syncro Spark module ? If i will put the magnet 20 deg Btdc where will be retarded puint ?

2. the unipolar hall sensor is like an On/Off with a hysyeresis curve between on and off stade.
This time is calculated for initial retard and afrer this when the engine fire the time calculated is between two consecutive "ON" ?

1The Synco spark has 26 degrees of timing movement built in. Static set to 30 degBDTC means 4 deg BDTC startup timing. 20 Deg BDTC means 6 deg ATDC startup.
Order soon we may have a few 20 deg chips left
2 Close enough, the hall switch produce a square wave, other wise thats right