|View Poll Results: What’s the most important thing to you?|
|Lowest possible cost||3||23.08%|
|Make it as small and light as possible||6||46.15%|
|Battery longevity is very important||3||23.08%|
|Highest power possible||3||23.08%|
|Highest RPM possible||2||15.38%|
|Only use through hole construction||2||15.38%|
|No winding of transformers||4||30.77%|
|Group buy of components including boards||0||0%|
|Group buy of boards only||1||7.69%|
|I’d rather buy a kit with everything in it||0||0%|
|I want to buy a pre-built & pre-programmed system||0||0%|
|I only want to use a 4.8v Ni-MH battery||2||15.38%|
|I only want to use a 2S battery||1||7.69%|
|I only want to use a 3S battery||1||7.69%|
|I want to use a 4.8v battery to 3S battery||5||38.46%|
|I want to use only off the shelf parts from Digi-Key or Mouser||3||23.08%|
|I want the Timer board to be separate from the HV board||6||46.15%|
|I want a combination Timer & HV board||1||7.69%|
|I want all the options possible using jumpers||3||23.08%|
|I want a USB connection||2||15.38%|
|I want a serial connection (DB9) and I’ll use my own USB adapter||3||23.08%|
|I want a ICSP connection||3||23.08%|
|I want a premade parts list (BOM) at Digi-Key||2||15.38%|
|I want a premade project parts list (BOM) at Mouser||1||7.69%|
|I want 1 design and 1 design only||1||7.69%|
|I want optional designs to choose from and Ill make the boards myself||8||61.54%|
|Multiple Choice Poll. Voters: 13. You may not vote on this poll|
|Feb 08, 2015, 06:28 PM|
I know you were thinking of using the 1840 for pulsing the step-up transformer, did you try a circuit yet? Sparky-1 is a good circuit because everything is broken out as much as I could do it. It is a good teaching circuit. Using a 12F1840 or a MC3406 to pulse or turn the primary current on/off is better but, they are more complicated to use.
I have seen circuits that use 1or 2 transformer/s and 1 or 2 caps to boost the voltage higher (like 1300v). The biggest problem is the charging time, this is where the Time Constant of a capacitor comes in. Also the step-up transformer must be able to handle the charging current and the power supply must be able to deliver the current. Almost all CDI ignition coils will quit sparking when the primary voltage on the coil drops to 100-120v. As the RPM goes up there is less time to charge, eventually you hit a point where you can no longer charge the caps up fast enough. 1.3Kv should be good for @ 60,000 RPM on a 1 cylinder 2 stroke engine and 15,000 RPM on a 4 stroke 8 cylinder all CDI. Also 1.3Kv is hard to control and keep in the wires, furthermore do we need that much energy?
I am a big fan of SMD components but, unfortunatly most hobbyists and DIY's aren't, so keeping this in mind I try to make all my shared circuits through-hole (PTH). With SMD there are more parts available and they are smaller.
Temperature has very little effect until about 75C when you might start to see something, at 105C caps will start to fail and at 150C transformers will start to fail. I constantly monitor temps when I'm testing and if the temps get to high I change the design. I would like to put a RTD in the exhaust to have the 1840 montitor exhaust temps.
|Feb 09, 2015, 05:10 AM|
United States, ID
Joined Sep 2011
There's a couple potential problems though. If we charge before the SCR turns off then we'll have problems. I'm also not sure how easy it will be to get everything working right since there will be a lot going on at once.
One thing I found with my quasi-resonant experiments is that it's pretty easy to control primary current through timing, and it's not hard to get ZVS using preprogrammed delays. I'm not sure if this will hold throughout a range of input voltages, but if it's close enough I would think there should be no problems.
|Feb 09, 2015, 08:06 AM|
To calculate the R/C or L/R time constants for charging and discharging of coils and caps and to calculate the delay:
Simple explanation: http://www.learnabout-electronics.or.../dc_ccts45.php
More complex explanation: http://en.wikipedia.org/wiki/RL_circuit
For coil charging use the inductance of the primary side and the resistance of the transistor or IGBT or whatever you are using to turn the circuit on & off.
For coil discharge it depends on which coil we are talking about but, use the resistance of the components on the secondary side only.
|Feb 12, 2015, 11:39 AM|
France, Pays de la Loire, Chalonnes-sur-Loire
Joined May 2013
a toroidal transfo 220V/12V 4VA producing H.T. for experiment , and that's sufficient to spark on a 125CC motor. I think on sparky1, the CCFL (1300V 6W) is not exploited at its max. I have posted a calc sheet to explain that if the voltage doubles the energy squares and the value of the capa(s) can be smaller, the challenge for the rc purpose!
There are 650V CCFL: but difficult to find on the market... I have now two on a samsung supply card( ccfl ref TM-2326 HYD750DCI), but they are big (maybe 14W), .
|Mar 03, 2015, 05:03 PM|
Joined Jul 2014
If you would like to build, rather than buy, an Arduino type development board, here is an Open Source site for the "Pinquino;" based on PIC18F2550:
It is also documented for a 18F4550 version.
Also do searches for "Pinquino" and "18F4550 Bit Wacker." You will find lots of additional information.
I have created a "stick" style, double sided, 18F4550 development board... See attachment. I call it "The Sandwich." It is about 3.5" x 1.25." The folder has Eagle files. (I am not the author of the circuit, just the board layout.)
If you have questions, please send me a private message, so we don't end up highjacking this thread...
|Mar 04, 2015, 09:15 AM|
France, Pays de la Loire, Chalonnes-sur-Loire
Joined May 2013
Hi Tee One Dee
i' m looking for a domotic solution (some n.t.c. and relays), and that would be a choice.
In parallel, i want a mini usb/B on my C.D.I., and my choice for the interface is actually on the MCP2221, from microchip also, but i have not statued.
Sometimes this site is difficult to domesticate... (i had problem of time-out with multiple tabs opened in firefox...
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