Ignition Coil Driver Questions

[WHONOES]

See attached a schematic for the first part of your circuit. It covers the 200V generator. I have included notes.
I would suggest that you build it one bit a time starting with the oscillator. As an aside, you could use a 4093 in place of the 40106. Just join the 2 inputs together.
Come back if you have any problems. Once you have got this bit working ok we'll go onto the pulse bit (which I haven't designed yet).

 

[QMESAR]

Hi
Thank you very much ,I can only say I will do my best to build it and get it working ,it can take a few days as our local electronic store does not have much and if they have to order the components it can take some time .I will be back once I have build the circuits thanks a million your a kind person .

PS, Thank you for the clear descriptions around the circuit ,I am sure I can build this ,will go look for the parts tomorrow ,The MOSFET and Diodes I do have ,it is only the Transformer and the Schmidt trigger IC the rest I all have in garage

 

[duke37]

D1 to D4 could be replaced by a single diode if it were connected the right way round.
A faster diode than the 1N4007 would be advantageous, I suggest a UF4007.

 

[QMESAR]

D1 to D4 could be replaced by a single diode if it were connected the right way round.
A faster diode than the 1N4007 would be advantageous, I suggest a UF4007.

Thanks for the comment however I believe I must crawl before I can walk or run for now I will stay with the circuit as WHONOES has tested and posted.
He has put in an large effort to help me which very few people were prepared to do ,I stick to his circuit as these vague suggestion (replace with one diode if connected the right way around )helps me nothing if not shown what is the correct way around and secondly for me 1 or 4 diodes make no difference it is a hobby project not commercial that cost is an issue

 

[duke37]

When Q1 turns off, a large voltage is generated on the drain and if the transformer is connected as shown, a much larger voltage is generated at the lower end, The upper end must be connected to earth , leave or short D2. D3 passes the positive pulse to the output. There is little disadvantage in using a bridge but means the transformer can be connected either way round. A single 1N4007 will cost the magnificent 1p but turns off relatively slowly and may overheat. A UF4007 may be 5p and four will be 20p so a mortgage will not be mandatory.

The simpler the circuit, the easier it is to make correctly and less likely to go wrong. WHONOES has done a good job which is why I have not intervened before, I thought I would add a little polish, I am sorry if it is not welcome.

 

[QMESAR]

The simpler the circuit, the easier it is to make correctly and less likely to go wrong. WHONOES has done a good job which is why I have not intervened before, I thought I would add a little polish, I am sorry if it is not welcome.

@duke37 My appologies it was not the intention to make my comments sound like your advise are not welcome , I do appreciate what WHONOES has done, he actually build and tested the circuits to help me , and figured I go his way to get going regarding the UF4007 diodes I will see if I can get them ,I am in a rural country where things are hard to get .

 

[QMESAR]

Hi All,
I went to our local electronic shop ,They can order the transformer for me takes about 2 weeks to deliver to Siberia ,
Please can you check if this is the correct Transformer ,UF4007 Diodes they have stock ,I also have with me 1N4007 ,I will get some UF4007 diodes , The Trigger they have in stock is a CD40106 from TEXAS Instruments ,I suppose this is correct ?

The polypropylene capacitor is really a problem needs to order it from EU can take 1 month ,is there something similar that I can use
Paper or metal Capacitor ?

Transformer 1.6W 2 x 7V Primaries 114mA and 2 x 115V Secondaries .

 

[WHONOES]

D1 to D4 could be replaced by a single diode if it were connected the right way round.
A faster diode than the 1N4007 would be advantageous, I suggest a UF4007.

Yup, it would work with a single diode. The 1N4007 works fine.

 

[WHONOES]

Hi All,
I went to our local electronic shop ,They can order the transformer for me takes about 2 weeks to deliver to Siberia ,
Please can you check if this is the correct Transformer ,UF4007 Diodes they have stock ,I also have with me 1N4007 ,I will get some UF4007 diodes , The Trigger they have in stock is a CD40106 from TEXAS Instruments ,I suppose this is correct ?

The polypropylene capacitor is really a problem needs to order it from EU can take 1 month ,is there something similar that I can use
Paper or metal Capacitor ?

Transformer 1.6W 2 x 7V Primaries 114mA and 2 x 115V Secondaries .

View attachment 47959

A 7-0-7 secondary is not mandatory. It could be 5-0-5, 6-0-6, or even 12-0-12. If it is the 12-0-12 then only one winding need be used. It could, of course, have just a single 12V secondary. It really depends on what you can easily get or may have to hand. The transformer does not have to be a toroid, it is just what I had to hand. A conventional E,I lamination type would work just as well. As I said, what ever you have to hand or can get easily.
The CD 40106 is fine.

 

[WHONOES]

When Q1 turns off, a large voltage is generated on the drain and if the transformer is connected as shown, a much larger voltage is generated at the lower end, The upper end must be connected to earth , leave or short D2. D3 passes the positive pulse to the output. There is little disadvantage in using a bridge but means the transformer can be connected either way round. A single 1N4007 will cost the magnificent 1p but turns off relatively slowly and may overheat. A UF4007 may be 5p and four will be 20p so a mortgage will not be mandatory.

The simpler the circuit, the easier it is to make correctly and less likely to go wrong. WHONOES has done a good job which is why I have not intervened before, I thought I would add a little polish, I am sorry if it is not welcome.

You make a salient point regarding the fly back from the lower end of the transformer. Have checked with my trusty scope and it is about 50V peak which should be manageable for the IRF530.

 

[WHONOES]

Hi All,
I went to our local electronic shop ,They can order the transformer for me takes about 2 weeks to deliver to Siberia ,
Please can you check if this is the correct Transformer ,UF4007 Diodes they have stock ,I also have with me 1N4007 ,I will get some UF4007 diodes , The Trigger they have in stock is a CD40106 from TEXAS Instruments ,I suppose this is correct ?

The polypropylene capacitor is really a problem needs to order it from EU can take 1 month ,is there something similar that I can use
Paper or metal Capacitor ?

Transformer 1.6W 2 x 7V Primaries 114mA and 2 x 115V Secondaries .

View attachment 47959

Regarding the Polyprop' capacitor. Not sure if a paper type would be OK. Haven't used one in over 50 years. A polyester type may be OK.
As a thought, a motor start or run capacitor could work, again I haven't tried one so can't say for certain.

 

[QMESAR]

Great Thank you for all the good answers,I will check what they have on hand ,I am excited to get this part working asap ,
Have nice weekend what is left of it,

 

[QMESAR]

Good Morning WHONOES,
I check all my stuff in the garage and I found these two transformers they are PCB mount transformers but not 115 V
1- 230V primary and 1 12V secondary
1-230V primary and 2 x 9V secondary
if these could work it will save time a lot if not then I have to order the transformer The one they can order for me is also opposite to yours as your transformer is 7 0 7 secondary and 115V primary ,the one they can order for me is 7 0 7 Primary and 115V secondary ,I suppose I just connect correctly ,it will work .Thanks for looking at this

 

[WHONOES]

AS I said previously, the 7-0-7 is not mandatory, it was just what I hand to hand at the time. I see no reason why a single 12V secondary and single 230V primary should not work. Similarly, the 2 X 9V secondary and single 230V primary will probably work. You could use just a single 9V secondary. Try them and see what you get. Nothing wrong with a bit of experimentation. That's how we learn stuff.

 

[QMESAR]

Thank you , Well what I did in the mean time was that I made a small layout for the circuit and ready to put it through the small Chinese CNC tomorrow and then I will populate the board and run some real tests.
However running the circuit in Simulator(SPICE) after I measured the 12V coildand the 230V coil inductance with my cheap LCR meter(maybe not so accurately) and used these values for the transformer model it looks good(worked out well ) 194V at 1700Hz so excited to get the real circuit connected . Again I appreciate your help


[

 

[WHONOES]

Good. Glad you are having a go and getting results.
As a point of interest, when doing simulations of this type of oscillator, it pays to set capacitor C1's initial conditions to 0V otherwise it may not start or take a long time to start.

 

[hevans1944]

takes about 2 weeks to deliver to Siberia

Wow! That is very rural. May we ask where in Siberia that you live?

 

[QMESAR]

Wow! That is very rural. May we ask where in Siberia that you live?

Yes sure I live in Yakutsk [Якутск]




Yakutsk
Here is the english page on the wiki:
https://en.wikipedia.org/wiki/Yakutsk

Moderators note : added english page.

 

[QMESAR]

Good. Glad you are having a go and getting results.
As a point of interest, when doing simulations of this type of oscillator, it pays to set capacitor C1's initial conditions to 0V otherwise it may not start or take a long time to start.

Hi All,
That is very good advise thank you so much !
I have build the circuit with what I have at hand and it is somehow working (12 Secondary and 230V primary I just back drive as you did WHONOES) I can adjust the output voltage with the drive frequency with my multi meter I see 150V - 205V measured at the output .
I was afraid to put my little cheap scope on the output ,should it be ok ,if I use x10 probe setting ?

 

[hevans1944]

Not sure why you want to 'scope the output? The pulses at the 220 VAC winding are rectified and filtered in @WHONOES test circuit, so without much loading of that output all a 'scope should reveal is a constant DC level. Were you planning to use the pulses developed by the circuit, adjusting their frequency to correspond to the idle rpm of your V12 Jaguar engine? I think @WHONOES believes you need to switch the output of his circuit at the proper rate to do that. The rate at which his circuit is switched determines the transformer output voltage, which after filtering is then switched to correspond to the idle rpm. @WHONOES has not revealed his design for this second switching.

In the Jaguar's original ignition, I am guessing the bottom end of the coil primary winding (normally connected to distributor points) is connected to the EMU to provide the EMU with engine rpm information. This seems to correspond with your original drawing that asked about the RC snubber connection. So, are you trying to replace the real ignition coil with its points and distributor, and substitute a "dummy coil" for the sole purpose of making the EMU think it is connected to the V12 engine? That would allow you to test the fuel injection system without actually running the V12 engine, if that is your intent.

Some more clarification, please.