I believe Heavy duty refers to high current rating. Am i right sir ? .

Transformers will be specified in Watts or VA. Big, heavy transformers will be high wattage, little light-weight transformers will be low wattage.

 

Transformers will be specified in Watts or VA. Big, heavy transformers will be high wattage, little light-weight transformers will be low wattage.

Thank you sir. I'll try it out today and keep you posted.

 

Thank you sir. I'll try it out today and keep you posted.

What is your duty cycle of this coil?

IE- how many times per second do you sever the Input Signal to the smaller NPN to produce the spark?

At high frequencies - Inherent backflow from the coil, and phase mismatches between the coil and/or any LC parts of the circuit and the input NPNs put huge stress on all of it.

A coil may peak at over 10Amps - this is by design since current isn't exactly in short supply in a car (With a several-hundred-CCA battery and a hundred-and-something-Amp alternator). Make you DC power supply at least 120W and throw a couple 4,700uF 100V caps in parallel with the output of the rectifier to try and take some of the surge-load off the transformer when it's near half-wave (0-volt).

Remember a low-ESR capacitor (or RC) in parallel with the coil is the typical mechanism to protect upstream circuitry (which, in a car was the Lead Acid battery that could potentially arc across it's plates and incur damage).

 

What is your duty cycle of this coil?

IE- how many times per second do you sever the Input Signal to the smaller NPN to produce the spark?

At high frequencies - Inherent backflow from the coil, and phase mismatches between the coil and/or any LC parts of the circuit and the input NPNs put huge stress on all of it.

A coil may peak at over 10Amps - this is by design since current isn't exactly in short supply in a car (With a several-hundred-CCA battery and a hundred-and-something-Amp alternator). Make you DC power supply at least 120W and throw a couple 4,700uF 100V caps in parallel with the output of the rectifier to try and take some of the surge-load off the transformer when it's near half-wave (0-volt).

Remember a low-ESR capacitor (or RC) in parallel with the coil is the typical mechanism to protect upstream circuitry (which, in a car was the Lead Acid battery that could potentially arc across it's plates and incur damage).

Thanks for your suggestion sir.
"How many times per second do you sever the Input Signal to the smaller NPN to produce the spark?"- 30-50 times/Second

"What is your duty cycle of this coil?" 50%. I had never thought about this. Will increasing duty cycle make my circuit more efficient ?

 

Thanks for your suggestion sir.
"How many times per second do you sever the Input Signal to the smaller NPN to produce the spark?"- 30-50 times/Second


"What is your duty cycle of this coil?" 50%. I had never thought about this. Will increasing duty cycle make my circuit more efficient ?

Firstly - yes it could yield better efficiency - but that requires a fair bit of complex math to pinpoint it (Which is beyond me).

Secondly - I'd say you'd want to reduce the duty cycle (increase the time where no voltage is applied to the input pin). This would reduce the load on the NPN switching transistors and the supply as well as increase the time where the HV side is left to dissipate the last cycle before the primary is re-engaged.

I would experiment with the duty cycle until you find the best results (visually/audibly from the spark plug) - one would speculate that the greatest efficiency would be found at the "edge" of where it starts to diminish sharply.

 

Firstly - yes it could yield better efficiency - but that requires a fair bit of complex math to pinpoint it (Which is beyond me).

Secondly - I'd say you'd want to reduce the duty cycle (increase the time where no voltage is applied to the input pin). This would reduce the load on the NPN switching transistors and the supply as well as increase the time where the HV side is left to dissipate the last cycle before the primary is re-engaged.

I would experiment with the duty cycle until you find the best results (visually/audibly from the spark plug) - one would speculate that the greatest efficiency would be found at the "edge" of where it starts to diminish sharply.

Got it sir. I'll try it and keep you updated.