Ignition Coil sparks with Relay Driver/Interrupter

The NC contacts (one of the pair) of a 12 volt 10 amp DPDT relay are bridged by a .25 uF capacitor and wired in series with the relay coil to form a vibrator. The relay coil is then wired across the ignition coil primary. The capacitor is essential, but its value is not critical but it should be about 400 volts. I use a condenser from a points/condenser ignition system.
You only need one NC contact pair. The DPDT relay is easy to obtain but only half of it is used.

Category:

Science & Technology

Tags:

• Ignition
• Coil
• Induction
• HV
• High Voltage
• Spark
• Arc
• Interrupter
• Driver
• Relay
• Breaker
• Buzz
• trembler

[helixwinder]

Sorry, no schematic.

[Migillicuty420a]

how did you wire this up?

[helixwinder]

@Migillicuty420a Sorry if my description wasn't clear. You wire the relay so that the Normally Closed (NC) contacts are in series with the relay coil. One side of the relay coil is connected to the battery. The other side is connected to one of the NC contacts. The other NC contact is connected to the battery forming a buzzer. You put the capacitor across the NC contacts(aka points) as in a standard ignition system. Now you place the ignition coil primary across the relay coil. OK?

[toadsEATbugs]

what does the relay look like?

[helixwinder]

@toadsEATbugs Visit the Futurlec site and see the part no. GR12V10ABL. I'm using the Radio Shack 12 volt 10 amp DPDT relay. Futurlec's is the same and costs less.

[125varma]

Hello :) I have got a relay, but it doesn't show NC contacts, but it has numbers such as 87, 87a, 30 and... Could you please send me the circuit of your coil driver? I would really appreciate it if you could do so :) My email address is: morad.murat@yahoo.com

[remzi133]

Great sparks!

[hscess]

How long will the relay last. Hopefully a long time? I like your setup.

[Hvdavi]

@helixwinder for beter sparks you can usea a microwave oven cap

[prototype9000]

works good with lawnmower magnetos to