I built a portable propane pizza oven. I light it manually.

I want to install an ignition system that is battery operated. Not piezoelectric. I could buy one but I want to learn how they work.

Can anyone steer me towards a published circuit please

Thanks in advance

Mellisa

 

Look for spark generator circuits.

There are a lot of different ones, but I think most of them are based on an LC tank circuit that is charged by a battery when the button is pressed and when it is released the tank circuit rings. The inductor is part of a transformer (possibly an autotransformer) that generates high voltage across a gap.

 

Search youtube for Spark generator or Spark plug tester...

 

I applaud your wish to build it your self Mellisa ... that is how you learn ..
Some may be drawn to this thread looking for an off shelf item , and I have to mention this

It's the electronic package you find in a taser ...a very serious item input 3-6 volts @2A output 400Kv .. hundreds are being sold on eBay at $2 each , I don't now what people are doing with them , but it would make a very nice spark!

 

Look for spark generator circuits.

There are a lot of different ones, but I think most of them are based on an LC tank circuit that is charged by a battery when the button is pressed and when it is released the tank circuit rings. The inductor is part of a transformer (possibly an autotransformer) that generates high voltage across a gap.

Many thanks

I did as you suggested and found this. It uses a car engine coil to build up a high voltage through induction. An oscillator circuit (not shown) produces a pulse into a MOSFET which starts the process.

All good. However, I don't understand why or if the spark plug is necessary. I don't know how spark plugs work. If the spark plug does something integral to the circuit then I can't use the circuit because it's an engineering problem I don't want to tackle to get the bulky plug into the burner.

Can the spark plug be replaced or dispensed with?

 

I applaud your wish to build it your self Mellisa ... that is how you learn ..
Some may be drawn to this thread looking for an off shelf item , and I have to mention this

It's the electronic package you find in a taser ...a very serious item input 3-6 volts @2A output 400Kv .. hundreds are being sold on eBay at $2 each , I don't now what people are doing with them , but it would make a very nice spark!

 

I applaud your wish to build it your self Mellisa ... that is how you learn ..
Some may be drawn to this thread looking for an off shelf item , and I have to mention this

It's the electronic package you find in a taser ...a very serious item input 3-6 volts @2A output 400Kv .. hundreds are being sold on eBay at $2 each , I don't now what people are doing with them , but it would make a very nice spark!

No thanks!! I don't want to mess with that. How can 800,000 watts go down skinny wires like that? I could die

 

Search youtube for Spark generator or Spark plug tester...

Thankyou I did find something I liked and posted about it in reply to @WBahn

 

Thankyou I did find something I liked and posted about it in reply to @WBahn

Thanks for this link. It's not for me though: it relies on a hack of an existing product which I don't have available.

This is a YouTube video with a circuit diagram presented in one frame. I can't capture the diagram and examine it. I need a circuit diagram on a page so I can see it and preferably with a commentary.

 

Can the spark plug be replaced or dispensed with?

Yes.
If the ground wire is attached to the burner of your pizza oven, you just need a non-meltable conductor on the end of your spark plug wire. It should be mounted near the burner so the spark will jump through the propane stream. Where you mount it needs to be insulated.

 

I’m posting this because you said you wanted to learn, so I am going to make two corrections…

1. Do not times the input current by the output voltage, so no that unit is not 800,000 watts.
2. Wattage does not “travel” in a circuit, it is produced at different points.

 

Yes.
If the ground wire is attached to the burner of your pizza oven, you just need a non-meltable conductor on the end of your spark plug wire. It should be mounted near the burner so the spark will jump through the propane stream. Where you mount it needs to be insulated.

Brilliant! Thankyou.

So just to be clear, the hot wire (currently on the top of the spark plug in the diagram) can act directly as the electrode in the propane stream with ground electrode within say a few millimetres also in the propane stream. No need for a sparkplug, yes?

 

I’m posting this because you said you wanted to learn, so I am going to make two corrections…

1. Do not times the input current by the output voltage, so no that unit is not 800,000 watts.
2. Wattage does not “travel” in a circuit, it is produced at different points.

Many thanks I'm eager to learn. I thought the 2A was I'm the output.

 

The output would be in micro amps.

 

Yes, No need for a spark plug but you don't want the wire to melt or short out where it is mounted. A rigid piece of clothes hanger wire could be mounted a few inches away from the spark end and would be easily adjustable and cheap to replace if it melts. Silicone glue is heat resistant.

 

Brilliant! Thankyou.

So just to be clear, the hot wire (currently on the top of the spark plug in the diagram) can act directly as the electrode in the propane stream with ground electrode within say a few millimetres also in the propane stream. No need for a sparkplug, yes?

You don't need a spark plug but you do need a spark gap. That is what a spark plug provides.
A spark gap is made up of two pieces of metals connected to the output of the HV power supply. The tips of the two pieces of metal are separated by a gap about 0.5-1.0 mm and placed within the area of the ignitable gas (not in the ensuing flame itself). The metal and mounting material must be able to withstand the heat of the flame. The commonly used material to hold the tips in place is usually ceramic.

 

You don't need a spark plug but you do need a spark gap. That is what a spark plug provides.
A spark gap is made up of two pieces of metals connected to the output of the HV power supply. The tips of the two pieces of metal are separated by a gap about 0.5-1.0 mm and placed within the area of the ignitable gas (not in the ensuing flame itself). The metal and mounting material must be able to withstand the heat of the flame. The commonly used material to hold the tips in place is usually ceramic.

 

Many thanks I've got it now. Spark plugs nothing more than rigid electrode keeping constant gap within a ceramic body within a metal threaded body that keeps the fuel mixture sealed from the atmosphere.

I always thought they were more than that.

 

Many thanks

I did as you suggested and found this. It uses a car engine coil to build up a high voltage through induction. An oscillator circuit (not shown) produces a pulse into a MOSFET which starts the process.

All good. However, I don't understand why or if the spark plug is necessary. I don't know how spark plugs work. If the spark plug does something integral to the circuit then I can't use the circuit because it's an engineering problem I don't want to tackle to get the bulky plug into the burner.

Can the spark plug be replaced or dispensed with?

A car ignition circuit is close to what you want, but there are some differences.

A car ignition has critical timing needs. The fuel-air mixture is highly compressed and easily ignited and the ignition has to occur within a very narrow time window of ten or twenty microseconds. So the circuit produces a single, high energy spark.

For a propane burner, the timing is immaterial but the fuel-air mixture is very low pressure and, relatively speaking, not as easily ignited. So a typical battery-operated circuit produces a number of relatively low energy sparks, only needing one of them ignite the mixture. Piezo circuits generally only produce a single spark, which is why you often have to activate them a number of times in order to get ignition.

 

I built a portable propane pizza oven. I light it manually.

I want to install an ignition system that is battery operated. Not piezoelectric. I could buy one but I want to learn how they work.

Can anyone steer me towards a published circuit please

Thanks in advance

Mellisa

The tricky bit is the HV pulse transformer - they're available as salvage from gas stoves & central heating units.

Its essentially a CDI unit, one of the UK magazines did an almost copy of a commercial product.

You need a blocking oscillator converter to generate a tad over 250V. the project used a 1.5v cell, the pot core had 15T oscillator windings and a 250T HV secondary. 15R resistor in series with the base winding. can't remember the transistor type, but it was rated 80V in a TO5 can.

The capacitor discharge bit uses a Siemens high energy discharge device with 220V breakdown - they sometimes turn up on telephony gear and modems. You might get away with an SCR if you drive the gate via a diac fed by divider resistor from the HV reservoir cap, they break over somewhere around 32V ish.

The capacitor is 1uF - at the time, the only survivable type found was made by ITT, but others exist.