Ignition circuit query

[MMK]

I followed this circuit diagram for making my ignition Circuit and connected it to an ignition coil of a car but it does not produce any spark at the spark plug?? Where do I get it wrong??? Also I didnt had 3 in qty 22000 ohm resistors that is why i used 27000 ohm resistors in place of the two resistors connected at pin 2 of NE555 IC! the other 22000 ohm resistor is correct!

 

 

Also I am using a 12V 80 Amps Car battery for powering this circuit!

 

 

 

Plz help me on this!!!!

Edited June 10, 2013 by MMK

[pwagen]

It's kind of hard to know what's wrong without actually having a look at your setup. The obvious thing to do would be to check if you've made a mistake. Is everything rotated the way it's supposed to? Is everything connected where it's supposed to be?

 

After that, start measuring. Make sure pins 4 and 8 are supplied with the right voltage (should be 12 V if you're connecting it to a car battery). Make sure pin 3 is around 1.7 V below what you measured at pin 8 (if I'm reading the link below right). Make sure your components can operate at 12 V, so they don't burn.

 

I'll look into the resistors you changed for 27k, see if they'd make a difference.

 

http://en.wikipedia.org/wiki/555_timer_IC#Astable

[Externet]

Is the ignition coil metal body connected to the spark plug thread ?

 

You need to probe for pulsing at pin 3 and bases of transistors.

[MMK]

No! The Ignition Coil is not metal body bottle shaped one......... Its a standard Suzuki Cultus Coil!

 

@pwagen:-

When the Coil was connected with my circuit I didnt get ant potential difference w.r.t ground at pin 3...... but pin 4 and pin 8 shows 12 Volts! All I get is around 2 Volts at the base of transistor BC559 that is after 5.6Kohm resistor at pin 3! Even if I disconnect the whole Pin 3 with the 5.6K ohm resistor I am getting No output at Pin3..........

 

I am using a Multimeter to check for voltages!

 

But when I disconnected this Ignition Coil from my circuit....... the Pin 3 showed a potential difference of around 11.86 V! Pin 8 and 4 showed 12.26 Volts!.......

Edited June 12, 2013 by MMK

[MMK]

Umm do u think my IC has burned or something? plz help its urgent!!!!

[Brett Nortje]

Well, if you were to take the ignition circuit, and redesign it so it is simpler, you got to look at what you want it to do, and in this case, you want it to ignite the engine. So, you need to hook it up to your car lighter. then, you need to push it in and watch the sparks - the power used in the lighter will easily light the engine, yes?

 

Or, you could hook the key up so that it carries a charge. when you twist it, it could have a 'battery' and send a shock to the engine. don't connect the circuit, simply make the key go between the circuit to connect it, and off you go.

[MMK]

Well, if you were to take the ignition circuit, and redesign it so it is simpler, you got to look at what you want it to do, and in this case, you want it to ignite the engine. So, you need to hook it up to your car lighter. then, you need to push it in and watch the sparks - the power used in the lighter will easily light the engine, yes?

 

Or, you could hook the key up so that it carries a charge. when you twist it, it could have a 'battery' and send a shock to the engine. don't connect the circuit, simply make the key go between the circuit to connect it, and off you go.

 

Umm Sorry but I dont intend to use it in a car.......... ! I am a Mechanical Engineering Student and am designing a Micro Gas Turbine......... Wanna use this on that!

 

No! The Ignition Coil is not metal body bottle shaped one......... Its a standard Suzuki Cultus Coil!

 

 

@pwagen:-

When the Coil was connected with my circuit I didnt get ant potential difference w.r.t ground at pin 3...... but pin 4 and pin 8 shows 12 Volts! All I get is around 2 Volts at the base of transistor BC559 that is after 5.6Kohm resistor at pin 3! Even if I disconnect the whole Pin 3 with the 5.6K ohm resistor I am getting No output at Pin3..........

 

I am using a Multimeter to check for voltages!

 

But when I disconnected this Ignition Coil from my circuit....... the Pin 3 showed a potential difference of around 11.86 V! Pin 8 and 4 showed 12.26 Volts!.......

 

This 11.86V reading appears only when the 5.6K ohm resistor is disconnected from pin 3 of 555 IC!

[pwagen]

But when I disconnected this Ignition Coil from my circuit....... the Pin 3 showed a potential difference of around 11.86 V! Pin 8 and 4 showed 12.26 Volts!.......

This 11.86V reading appears only when the 5.6K ohm resistor is disconnected from pin 3 of 555 IC!

Ok, so you need to disconnect both the coil and the resistor to get that voltage? Or is it enough to just disconnect the coil? Sounds a bit like the coil might be the problem then.

[Externet]

MMK:

The coil 'metal body' for that Suzuki one is still its non-insulated metal body iron core, as the bracket seems insulated on rubber mounts, or one of the primary terminals is also common with the secondary. It has to connect to the spark plug thread.

 

To see pulses on pin 3 you need to use an oscilloscope. A DC volt meter will not tell such, will show high or low depending on the oscillator status, or somewhere in between for AC scale, which may kind of detect/read the oscillation.

 

If the contraption is not going to operate in a vehicle, you do not need to make it work with a 12 Volt battery nor the oscillator circuitry.

Pick a 'wall wart' 120VAC to 12VAC transformer and connect your coil primary to it, nothing else. Watch were you put your fingers or you may get the jiggles.

[MMK]

Ok, so you need to disconnect both the coil and the resistor to get that voltage? Or is it enough to just disconnect the coil? Sounds a bit like the coil might be the problem then.

 

It takes both the Resistor and Coil to be disconnected to get the above stated readings!

 

MMK:

The coil 'metal body' for that Suzuki one is still its non-insulated metal body iron core, as the bracket seems insulated on rubber mounts, or one of the primary terminals is also common with the secondary. It has to connect to the spark plug thread.

 

To see pulses on pin 3 you need to use an oscilloscope. A DC volt meter will not tell such, will show high or low depending on the oscillator status, or somewhere in between for AC scale, which may kind of detect/read the oscillation.

 

If the contraption is not going to operate in a vehicle, you do not need to make it work with a 12 Volt battery nor the oscillator circuitry.

Pick a 'wall wart' 120VAC to 12VAC transformer and connect your coil primary to it, nothing else. Watch were you put your fingers or you may get the jiggles.

 

Sir are u proposing to run an ignition coil with stepped- down Alternating Current? I heard that an ignition coil works on pulsed DC! plz elaborate on it! Thanks!

[Externet]

Transformers run on alternating current. That ignition coil is a transformer. What you heard does not matter. Nothing to elaborate; D O I T !

[MMK]

Okay I will do it today! If anything happens I will surely hit u okie!

Transformers run on alternating current. That ignition coil is a transformer. What you heard does not matter. Nothing to elaborate; D O I T !

 

Btw will it work with just any step down transformer...... whose output is at 12VAC?

[arc]

Hello MMK, my experience with 12 V coils tells me your coil requires a saturation, a quick drop in voltage that produces the spike in secondary voltage. An old system had a set of points that opened to initiate the coil collapse, the condenser eliminates the voltage arc that would jump the open points. Yours is electronic but is the same in principle. Does your coil have an internal capacitor? Is your coils capacitor tuned to that coil? Those two have to oscillate together to produce inductance in the secondary side. Have you ohm tested the coil? Both secondary and primary. Some coils need the braket to be grounded to work, others use the neg. for both primary and secondary. arc

[MMK]

Hello MMK, my experience with 12 V coils tells me your coil requires a saturation, a quick drop in voltage that produces the spike in secondary voltage. An old system had a set of points that opened to initiate the coil collapse, the condenser eliminates the voltage arc that would jump the open points. Yours is electronic but is the same in principle. Does your coil have an internal capacitor? Is your coils capacitor tuned to that coil? Those two have to oscillate together to produce inductance in the secondary side. Have you ohm tested the coil? Both secondary and primary. Some coils need the braket to be grounded to work, others use the neg. for both primary and secondary. arc

 

Yeah I have ohm tested this coil and i know its perfectly okay!

 

I think this circuit might not be working for me because i might not have used the correct resistors Pin 7 and 2, 6! I used 27k ohm ones in place of 22k ohm!!! What do u all think?? is it might be the problem???

 

Transformers run on alternating current. That ignition coil is a transformer. What you heard does not matter. Nothing to elaborate; D O I T !

 

Sir I followed your advice but it didnt worked!! What should I do now??? i am already short on time and this thungy has taken a toll on me!!!! plz helpppppppppppppp!

[Spyman]

I think this circuit might not be working for me because i might not have used the correct resistors Pin 7 and 2, 6! I used 27k ohm ones in place of 22k ohm!!! What do u all think?? is it might be the problem???

I don't think those resistors are the problem, they determine the timing of the pulses and unless a change from 10 Hz to 8 Hz is crucial, then the circuit should work.

 

In the astable mode, the frequency of the pulse stream depends on the values of R₁, R₂ and C:

The high time from each pulse is given by:

and the low time from each pulse is given by:

where R₁ and R₂ are the values of the resistors in ohms and C is the value of the capacitor in farads.

http://en.wikipedia.org/wiki/555_timer_IC#Astable

 

 

With R₁=22k R₂=22k and C=2.2µ the Output at pin 3 is High for 0.067 seconds and Low for 0.034 seconds -> frequency = 9.9 Hz.

 

With R₁=27k R₂=27k and C=2.2µ the Output at pin 3 is High for 0.082 seconds and Low for 0.041 seconds -> frequency = 8.1 Hz.

 

 

Step 1 is to determine if the output at pin 3 is pulsing or not, this can be done with an oscilloscope or by temporarily unconnect the 5.6k resistor and instead connect a very small 12 VDC light bulb no more than 2 Watts, or a LED in series with a 1k resistor between pin 3 and ground. It should blink around 8 to 10 times each second.

 

If step 1 is OK then the 555 circuit is working properly.

 

 

Step 2 is to connect a small 12VDC light bulb where the ignition coil is ment to be, it should flash rapidly.

 

If step 2 is OK the power transistors are working properly.

 

 

Step 3 is to connect a large 12VDC light bulb where the ignition coil is ment to be, it should flash rapidly.

(With large I mean that it needs to drain an equal amount of current as the coil does.)

 

If step 3 is OK then the problem is with the coil or spark plug.

 

 

EDIT: Changed the typo "pin 2" to the correct "pin 3" in Step 1.

Edited June 13, 2013 by Spyman

[MMK]

Umm Sir isnt it should be pin 3 rather than pin 2? plz tell me.........

[Spyman]

Umm Sir isnt it should be pin 3 rather than pin 2? plz tell me.........

Yes, of course, pin 3, typo.

 

(Edited post #15 to fix it.)

Edited June 13, 2013 by Spyman

[Externet]

Sir I followed your advice but it didnt worked!! What should I do now??? i am already short on time and this thungy has taken a toll on me!!!! plz helpppppppppppppp!

That is unusual. It has worked for me fime testing ignition coils, several times, jumping a spark across the spark plug. What is the measured AC voltage on the primary while energized ?

 

Plan B : Get an automotive relay and connect its common and normally closed contacts in series to your 12V DC battery source. It will provide a faster turn-off. Let me see if I find a schematic for your better understanding...

 

 

+12V--------------C---/ .----NC------------coil primary-------------GND

 

NC------------relay coil----------------GND

 

In other words, both coils in parallel betwee the NC contact of the relay and battery minus. But remember the spark plug thread must be connected to the secondary or common, whatever your coil has.

 

Here is something :

http://www.popsci.com/diy/article/2009-12/shocking-truth-how-make-high-voltage-sparks

 

Come back with results.

 

If you cannot make it work and short on time... try a gas stove spark module, available from most discarded ones or at the appliance parts store.

Edited June 13, 2013 by Externet

[MMK]

That is unusual. It has worked for me fime testing ignition coils, several times, jumping a spark across the spark plug. What is the measured AC voltage on the primary while energized ?

 

Plan B : Get an automotive relay and connect its common and normally closed contacts in series to your 12V DC battery source. It will provide a faster turn-off. Let me see if I find a schematic for your better understanding...

 

 

+12V--------------C---/ .----NC------------coil primary-------------GND

 

NC------------relay coil----------------GND

 

In other words, both coils in parallel betwee the NC contact of the relay and battery minus. But remember the spark plug thread must be connected to the secondary or common, whatever your coil has.

 

Here is something :

http://www.popsci.com/diy/article/2009-12/shocking-truth-how-make-high-voltage-sparks

 

Come back with results.

 

If you cannot make it work and short on time... try a gas stove spark module, available from most discarded ones or at the appliance parts store.

 

at primary it was 12 VAC and i am getting 220 VAC at my wall socket @ 50Hz frequency!

 

I don't think those resistors are the problem, they determine the timing of the pulses and unless a change from 10 Hz to 8 Hz is crucial, then the circuit should work.

 

In the astable mode, the frequency of the pulse stream depends on the values of R₁, R₂ and C:

The high time from each pulse is given by:

and the low time from each pulse is given by:

where R₁ and R₂ are the values of the resistors in ohms and C is the value of the capacitor in farads.

http://en.wikipedia.org/wiki/555_timer_IC#Astable

 

 

With R₁=22k R₂=22k and C=2.2µ the Output at pin 3 is High for 0.067 seconds and Low for 0.034 seconds -> frequency = 9.9 Hz.

 

With R₁=27k R₂=27k and C=2.2µ the Output at pin 3 is High for 0.082 seconds and Low for 0.041 seconds -> frequency = 8.1 Hz.

 

 

Step 1 is to determine if the output at pin 3 is pulsing or not, this can be done with an oscilloscope or by temporarily unconnect the 5.6k resistor and instead connect a very small 12 VDC light bulb no more than 2 Watts, or a LED in series with a 1k resistor between pin 3 and ground. It should blink around 8 to 10 times each second.

 

If step 1 is OK then the 555 circuit is working properly.

 

 

Step 2 is to connect a small 12VDC light bulb where the ignition coil is ment to be, it should flash rapidly.

 

If step 2 is OK the power transistors are working properly.

 

 

Step 3 is to connect a large 12VDC light bulb where the ignition coil is ment to be, it should flash rapidly.

(With large I mean that it needs to drain an equal amount of current as the coil does.)

 

If step 3 is OK then the problem is with the coil or spark plug.

 

 

EDIT: Changed the typo "pin 2" to the correct "pin 3" in Step 1.

 

Sir Step # 01 failed!!!! My LED failed to blink not even a single time....... but when I connect it to pin 4 or even 8 it lights up continuously......... but no blinking at Pin # 03!!!!!!! NOT EVEN ONCE! What should I do now???

Edited June 13, 2013 by MMK

[MMK]

I found out that my capacitor at pin 5 was short...... so I just removed it! Now this done I again connected LED at Pin 3 and yes it blinked rapidly!!!! Now Step 1 as well as step 2 stands verified!!! yupeeeee

But when I connected my ignition coil to it now, it didnt produced any spark!!! What might be the reason for this???

Edited June 13, 2013 by MMK

[Spyman]

Did you test Step 3? A light bulb from the headlights of a car should be large enough.

Does the LED continue to blink at pin 3 when the coil or a large light bulb is connected?

Does the LED blink when connected to the cross point between TR1, 1N4004 and 100 ohm resistor? With and without the coil?
(LED in series with the 1k resistor.)

Does the LED blink when connected from coil+ to coil-, with and without the coil?
(LED in series with the 1k resistor.)

Does the spark plug have a common grounding with the ignition coil so the secondary circuit is closed when a spark jumps?
(Watch out, high voltage in the range of 10 000 to 40 000 volts from the ignition coil's secondary winding when working.)

[MMK]

Did you test Step 3? A light bulb from the headlights of a car should be large enough.

 

Does the LED continue to blink at pin 3 when the coil or a large light bulb is connected?

 

Does the LED blink when connected to the cross point between TR1, 1N4004 and 100 ohm resistor? With and without the coil?

(LED in series with the 1k resistor.)

 

Does the LED blink when connected from coil+ to coil-, with and without the coil?

(LED in series with the 1k resistor.)

 

Does the spark plug have a common grounding with the ignition coil so the secondary circuit is closed when a spark jumps?

(Watch out, high voltage in the range of 10 000 to 40 000 volts from the ignition coil's secondary winding when working.)

 

No Sir Step # 3 is a failure! I couldn't light up my halogen lamp........ also that when i connect the LED at the coil terminals with Coil mounted it doesnt blink a bit! not even it lights up!

 

And without the coil......... LED fails to light up when connected at TR1 or Diode or 100 ohm resistor w.r.t ground!!!!

 

What should i do now sir???

[Spyman]

You did not answer if the LED still blinks from pin 3 when the halogen or coil is connected, does it?

 

What lamp did you use to check Step 2? Voltage and effect? The LED, instrument light 1-2 watt, taillight 10-25 watt or other?

 

Is the 1N4004 diode mounted in the correct direction? The side with the grey line on it should be connected between TR1 and the 100 ohm resistor, while the other side without the line should go to the ground.

If 1N4004 is turned upside down then the TR2 will be choked to only drain ~350 milliamperes or less through the coil/halogen.

 

 

It could also be that the power transistors was not meant to drive such a large load in this setting, the 100 ohm resistor determines how much TR2 will open up and it could have a to high value for a 4-5 ampere load, likewise the 5.6k ohm resitor might have a to high value to fully open TR1 and give the 100 ohm resistor the current it needs to open TR2.

 

Don't have more time right now but we can dive deeper into this later if needed.

[MMK]

You did not answer if the LED still blinks from pin 3 when the halogen or coil is connected, does it?

 

What lamp did you use to check Step 2? Voltage and effect? The LED, instrument light 1-2 watt, taillight 10-25 watt or other?

 

Is the 1N4004 diode mounted in the correct direction? The side with the grey line on it should be connected between TR1 and the 100 ohm resistor, while the other side without the line should go to the ground.

If 1N4004 is turned upside down then the TR2 will be choked to only drain ~350 milliamperes or less through the coil/halogen.

 

 

It could also be that the power transistors was not meant to drive such a large load in this setting, the 100 ohm resistor determines how much TR2 will open up and it could have a to high value for a 4-5 ampere load, likewise the 5.6k ohm resitor might have a to high value to fully open TR1 and give the 100 ohm resistor the current it needs to open TR2.

 

Don't have more time right now but we can dive deeper into this later if needed.

 

Sir I dont know how it happened but my TR1 transistor i.e., C559 is faulty! It was alright when I connected it in the first place! I will buy a new one tomorrow probably and will do further tests and inform u about it! And Sir the answer is no for whether the LED blinks when the circuit is connected to the Coil! And Sir I am using 1N4007 diode in place of 1N4004...... b/c I have plenty of them!

Edited June 14, 2013 by MMK

[MMK]

Thanks everyone....... my circuit is now working fine and its producing sparks too! Thanks for every ones help!!!!!!