|
RE: CH ignition versus Chinese version.
Well the RCXL we're running is showing about 800ma @ 10000.
|
RE: CH ignition versus Chinese version.
ORIGINAL: tkg Well the RCXL we're running is showing about 800ma @ 10000. That sounds reasonable. |
RE: CH ignition versus Chinese version.
In an earlier post, it was stated that, "At 8000 RPM the Rcxel draws 3000 mA." That figure also sounds reasonable. However, it's quite a bit different than 800ma at 10,000 rpm as stated by TKG. Did TKG mean 1,000 rpm, which would be about right for that current? John
|
RE: CH ignition versus Chinese version.
ORIGINAL: jpanhalt In an earlier post, it was stated that, "At 8000 RPM the Rcxel draws 3000 mA." That figure also sounds reasonable. However, it's quite a bit different than 800ma at 10,000 rpm as stated by TKG. Did TKG mean 1,000 rpm, which would be about right for that current? John Roger |
RE: CH ignition versus Chinese version.
Idea!![sm=idea.gif] This makes just too much sense.
Anyone that's terribly concerned with the engineering specs and theoretical designs of someone elses ignition should run out and buy one in question, run it on an engine with a prop that will let it turn 12,000-16,000 rpm and actually measure what it does and get back to everyone. Unless you're racing who the heck cares what the ignition draws over 8,000 rpm? It's easy to pick somebody elses work apart when you don't have any of your own on display. |
RE: CH ignition versus Chinese version.
ORIGINAL: Silversurfer Idea!![sm=idea.gif] This makes just too much sense. Anyone that's terribly concerned with the engineering specs and theoretical designs of someone elses ignition should run out and buy one in question, run it on an engine with a prop that will let it turn 12,000-16,000 rpm and actually measure what it does and get back to everyone. Unless you're racing who the heck cares what the ignition draws over 8,000 rpm? It's easy to pick somebody elses work apart when you don't have any of your own on display. R. |
RE: CH ignition versus Chinese version.
ORIGINAL: jpanhalt In an earlier post, it was stated that, "At 8000 RPM the Rcxel draws 3000 mA." That figure also sounds reasonable. However, it's quite a bit different than 800ma at 10,000 rpm as stated by TKG. Did TKG mean 1,000 rpm, which would be about right for that current? John If anybody cares a USA CH unit is 500ma @10,000rpm |
RE: CH ignition versus Chinese version.
So if you're going to fly really high rpm for extended periods a 2,400mAh regulated lion would give you a safe 3.5 hours, right?
|
RE: CH ignition versus Chinese version.
ORIGINAL: jpanhalt In an earlier post, it was stated that, "At 8000 RPM the Rcxel draws 3000 mA." That figure also sounds reasonable. However, it's quite a bit different than 800ma at 10,000 rpm as stated by TKG. Did TKG mean 1,000 rpm, which would be about right for that current? John BCCHI. The only ignition I no of that really draws 3000 MA is the one on the Zenoah G-20. We have a really good cure for that. |
RE: CH ignition versus Chinese version.
ORIGINAL: RCIGN1 Now you've done it, another product war....:eek: Bill tested all the other ignitions....He is now selling the rc exl Chinese ignition with his label on it....Good enough for me, I use Bill's US made circuit in all my Zenoah conversions and the Chinese C&H with engines that use separate ignition boxes....0 problems.If I converted the engine I will replace any of either one that ever fails, no charge...Beat that :D FWIW, Bill and I are the only ones that have been doing this continuously for at least 20 years, we probably have a good idea of what works and what doesn't...;) BCCHI |
RE: CH ignition versus Chinese version.
RCIGN1, No war here Ralph, WW2 was enough....I purchased an EI unit with the BCMA label?..... Not certain who or what brand, it's origin., or quality... Spending much time, and frustration, as close as I can get the timing is 28-30.. This is on a G-45.I've had no chance to fire it up(weather) and the old man was wondering if this is in the ballpark.. |
RE: CH ignition versus Chinese version.
I also second the low current draw of the RCexl ignition. The twin uses a bit more. I use a 1200 mAh battery pack, and it serves me well without having to worry about capacity.
In one test, the twin ignition reliably fired down to as low as 3.6 Volts and 7000 rpm. I found out, that if you start the engine, you should not hesitate, but handle that prop as if you mean business, or else don't. If flipped fast enough, there is no kickback at all. If turned over, or lazily flipped, it kicks back. When I took the 45cc engine to the field for others to play with, some found out that a live gas engine is no toy to be handled carelessly. No serious harm done though. Just a few raps on some knuckles, without blood being drawn. |
RE: CH ignition versus Chinese version.
The 10,000 rpm number has very little to do with reality when flying models. A basic test we do to check out units is to remove the side electrode from a spark plug, then spin it up to a mininum of 10k. A correctly working ignition will fire the .125" gap easily. If it passes this thes then it will run an engine at normal rpms.
|
RE: CH ignition versus Chinese version.
I believe the high current previously reported in this thread for the RCexl may all be a misunderstanding. The RCCDI site actually shows 500 mA at 3000 rpm and 1100 mA at 8000 rpm and 6 volts. How one measures the current (for example, peak or average) could make a big difference. I may actaully put a scope on the supply line and see what's really happening. However, enough people have commented about lower current needs, which are apparently average current values, that I can now plan accordingly. That is, I will use a smaller battery than I would have used, if the expected current was truly 3000 mA. Thanks. John
|
RE: CH ignition versus Chinese version.
Wow, this thread is generating some really interesting stuff and is certaintly expanding my learning curve about our electronic ignitions. Thanks to you all for your inputs so far.
Karol |
RE: CH ignition versus Chinese version.
That is how I tested the ignition at 7000 rpm. Objective in my case was to find the lower voltage for function.
At 3.6 Volts the pack was all but drained, and we stopped the test with ignition still sparking. |
RE: CH ignition versus Chinese version.
Hi
From which reason pic driven ignition works with sensor-magnet on 40 deg BTDC , max ret/min advance on low rpm and after rpm counting and calculate compared, move to min ret/ max advance? Old and good CH mechanical linked advance works with sensor/magnet on 2-4 deg BTDC and advane ignition with throttle opening gain rpm. I think is same principle in Falkon.cz electronic ignition. First flip at 2 deg BTDC. pro and cons ? BTY External Syncro Spark addapter from CH works also from 28 BTDC and with rpm gain , advance ? Thanks, |
RE: CH ignition versus Chinese version.
1 Attachment(s)
when there is a direct signal from sensor to discharge cirquit you can get away with simple reasoning and/or a mechanical advance contraption.
In the chinese ignition, the sensor just provides a signal to be processed by the pic algorithm, which in turn drives the discharge moment depending on rpm. The first spark has seen no rpm yet, so there is nothing to calculate. In my experience the first sparks have a simple time delay that allows for safe starting without kickback. Included is a pic processing curve of a similar Dutch design. |
RE: CH ignition versus Chinese version.
Hi Pe,
I know pic drive ignition principle. my question is: If i put side by side Falkon Ignition and "Chinese" ignition Falkon have fist spark on 2-4deg BTDC where sensor /magnet located and after this whith rpm increse move/advance it. Ignition advance with rpm increse. "Chinese " bring signal 40 deg BTDC delayed it (whitout calculating yet rpm) and have first spark somewhere.....depending how healty you bit the prop. Whay Chinesse algoritm is preffered? more accuracy on Hight RPM ? spark producet w/o delay ?? Maybe a compromise between, with 2 sensors one directly at 5 deg for starting and second at 40 deg driven by PIC ? Thanks for comments. |
RE: CH ignition versus Chinese version.
RC ign. I do not no what the deal is with the 40 degrees on the RCXL ign. I put a CHRCEXL on a engine that I had timed at 30 before TCD it turned the same RPM and responded the same as our CH timing board. I think some one is Dreaming. Looked at it both on a scope and timing light and they seemed to be exctly the same. They do not have my program that I no of ,but any pic writer could write the code. I will never learn to do T rolls, I think there is a secret we do not no.Maybe I am to old. BCCHI |
RE: CH ignition versus Chinese version.
Y'all listen to Bill, he knows..
I set all the conversions to 28 BTDC...It works just fine... My G26s are set to 28 BTDC with no electronic control, work fine.. Falkon ignitions are set to 2 BTDC static and advance... C&H heavy duty and Chinese ignitions work the same, static 28, retard when starting, full advance at 4000..... My old and C&H old with mechanical advance were set to 28 or 30, spark advanced with throttle opening, about 4 BTDC for starting, full advance at WOT, linear in between... All this talk about advance curves is confusing...If you think some type of curve between idle and 4000 rpm makes any difference, so be it, betcha you can't tell the difference...;) |
RE: CH ignition versus Chinese version.
To put a few things right first.
0) The chinese algorithm is not preferred. It works, and the ignition is reliable. That is most important. 1) Like Ralph said, 28 degrees fixed ignition works fine. My racer in days long gone had fixed contact breaker ignition (not at 28 degrees), yet would idle well. 2) With electronics, the timing can be retarded for safer starting. Old motorcycles had the manual ignition manette so you could set the ignition late for starting, or the kickstarter would launch you. 3) electronic ignitions can be made to switch off after a small time of inactivity. This is for safety 4) The ignition timing curve is realy unimportant. If it jumps from full late to full advanced at ~2500 rpm, that is OK. As long as full throttle timing is right, there will be no influence on power. The full rpm timing even has a sweet spot, so +- 2 degrees are no big deal. 5) Which ignition is used is not so important as the reliability of the spark arriving at the right time, every time. Considering all the above, and choosing an EI, multiple magnets have a few advantages over a single magnet, or fixed mechanical. 1) The ignition has more time to calculate when to fire 2) The calculations can be reset every revolution, so response time is quicker. 3) If the magnet angle is not 180 degrees, the ignition can sense direction of rotation and act upon it. 4) The time between the magnet passing can be used for many other things 5) Magnets of different polarity provide extra calculation possibilities ......... put your imagination here..... |
RE: CH ignition versus Chinese version.
Early Reichmuth ignitions had 2 magnets and would jump from starting to full advance around 2500 rpm...worked OK until you were landing and the rpm jumped from the high to the low and the plane would suddenly slow down...He later switched to one magnet...
The originator of the syncro spark the Bill used for so many years is on this forum, he might have a few words.. The syncro spark controlled ignition using 1 magnet is so stable that a timing light on the prop makes it look like you could reach right in and set the carb...At any rpm...[8D] |
RE: CH ignition versus Chinese version.
1 Attachment(s)
In this link:
http://www.mayimodel.com/shop_view.asp?id=703 As shown below you can see how to set up the rcexl ignition in a very simple and static way at 40 degrees. All you do is calculate the distance needed from magnet at TDC to center of the sensor corresponding to 40 degrees. I guess this angle will go down to 30 once the engine is running. I compared this setup to the one i have in my stock spe 26 engine and does not fit . Do you think this ignition setup method is o.k.? |
RE: CH ignition versus Chinese version.
gpar,
How many degrees is it off? Remember, the actual switching of the Hall sensor may occur before the magnet reaches the center of the Hall device. Also, although it is unlikely the magnet is in upside down, be sure it is situated correctly. I believe with that ignition, the South pole should be nearest the detector. And last, the value you calculate using pi for linear offest is actually an arc distance. What you are measuring with your calipers is the straight-line distance. The error is probably too small to mater (about 2%), but it could contribute to the overall error. In your case, the trigonometric calculation of the straight-line distance would be: Radius*(sin 40)/(cos20). It's been many years since I studied geometry, so be sure to confirm that equation for yourself. John I just did a quick estimate from a CAD program. The arc distance is 13.265mm, and the straight-line distance is 12.997mm. |
| All times are GMT -8. The time now is 07:43 PM. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.