Sparky-1 & Sparky-1E: A 5-Volt High-Voltage Board for CDI Ignitions
An open-source, flexible high-voltage board for CDI ignitions — free for personal use.
Sparky-1 was designed to be used with the open-source project Programmable Open Source CD Ignition PIC1840 located on the RC Groups forum, but it will work with almost any widely used signal input. In today's age of electronics, I don't feel it should be necessary to wind a step-up coil. I also don't really like ZVS, ZCD or Royer oscillator circuits because they are hard to control, so I used something I know: SMPS (Switch Mode Power Supply) technology. With SMPS I can use almost any step-up transformer I want, limit the voltage, and limit the power.
Sparky-1E is designed to use an external ignition coil like the Zenoah Grey Coil or the GY6 scooter coil.
I designed the Sparky-1 to be as flexible as possible and to be easily understood. Another major feature was that it had to run the whole circuit with 5 volts. For a detailed description of how the circuit works, read the circuit description PDF below. Sparky-1 is free to use for personal use only; commercial use requires a written agreement.
Main Features of Sparky-1/1E
- Whole circuit runs off 4.5 – 18 volts.
- Use 4.8-volt to 18-volt battery power.
- Adjustable high-voltage output with feedback circuit.
- Adjustable power output — use only as much as you need and save battery power.
- Adjustable frequency to match transformer uH and inductive reactance (XL).
- Half-bridge driver cuts out when battery voltage goes down to 4.1 volts.
- No complicated circuits — an excellent way to learn SMPS and CDI ignitions.
Batteries You Can Use
Use a 1500 mAh or greater battery. For a 4.8-volt NiCad or NiMH, don't use a regulator — remove it and jumper the regulator holes; the circuit will shut down at 4.1 volts. With a regulator you can use 6–18-volt NiCad or NiMH. For Lithium Ion / Poly / LiFePo you can use 6.6–18 volts, but you will need a volt monitor so you don't wreck the batteries.
Recommended Regulators
There are lots of different types of 5-volt positive regulators, and which one you use is up to you. Try to use one with at least 2 amps continuous duty and a drop-out voltage of 0.7 volts or lower. Max current with the parts I used was 1.8 amps, so it is best to use a 2-amp heatsinked regulator. I plan on using the side of the case for my heat sink.
Note: To use the Eagle files you need to use or upgrade to Eagle 6.4.0, otherwise you will get errors. All board files are 1:1 scale.
Any questions? Email me at rrichter@unimatrixtech.com.
Sparky-1 Files
- Sparky-1 Circuit Description.pdf — a detailed description of how the circuit works.
- Sparky-1 CDI HV Schematic IR2302-NE555.pdf — PDF of the schematic.
- Sparky-1 Eagle File CDI HV Schematic IR2302-NE555.sch — Eagle file of the schematic so you can make changes.
- Sparky-1 Eagle File CDI HV Schematic IR2302-NE555.brd — Eagle file of the board so you can make changes.
- BOTTOM LAYER POUR Sparky-1 CDI HV Schematic IR2302-NE555.pdf — bottom board layer with copper pour.
- BOTTOM LAYER Sparky-1 CDI HV Schematic IR2302-NE555.pdf — bottom board layer without copper pour.
- TOP LAYER POUR Sparky-1 CDI HV Schematic IR2302-NE555.pdf — top board layer with copper pour.
- TOP LAYER Sparky-1 CDI HV Schematic IR2302-NE555.pdf — top board layer without copper pour.
- Combined Layers Sparky-1 CDI HV Schematic IR2302-NE555.pdf — combined layers, 3X enlarged.
- Component Layout Sparky-1 CDI HV Schematic IR2302-NE555.pdf — components-only layer.
- Sparky-1 BOM CDI HV Schematic IR2302-NE555.pdf — PDF of the Bill of Materials.
- Sparky-1 BOM.xls — Bill of Materials in Excel 97-2003 format.
Sparky-1E Files
- Sparky-1 Circuit Description.pdf — a detailed description of how the circuit works.
- Sparky-1E Eagle File CDI HV Board External Ignition Coil.brd — Eagle file of the board so you can make changes.
- Sparky-1E CDI HV Schematic External Ignition Coil.pdf — PDF of the schematic.
- Sparky-1E NO FILL BOTTOM.pdf — bottom board layer without copper pour.
- Sparky-1E NO FILL TOP.pdf — top board layer without copper pour.
- Sparky-1E POUR FILL BOTTOM.pdf — bottom board layer with copper pour.
- Sparky-1E POUR FILL TOP.pdf — top board layer with copper pour.
- Sparky-1 BOM.xls — Bill of Materials in Excel 97-2003 format; just delete the RT-442 coil.
- BOM Sparky-1 1E CDI HV Schematic IR2302-NE555.txt — Bill of Materials in text format; just delete the RT-442 coil.
Movies of Sparky-1
Video demonstrations of the Sparky-1 in action (links to be added):
- CDI Spark Design 1
- Sparky-1 movie 2
- Sparky-1 Movie 3 — 21,000 rpm
- Sparky-1 Movie 4 — hits 37,200 RPM
- Sparky-1 Movie 5 — very low power usage
- Sparky-1 Movie 6 — big sparks, cool
- Inductive reactance adjust for power