Old electronic ignition

[mike1864]

(I've spun this out from the recent "1098 not starting" topic, as this story is of no help to that OP.)
My electronic ignition was probably the first to be fitted in a Minor, around 1973. I built it as a kit, as featured in an electronics magazine. It was all mounted in an Eddystone box. It retains the points, which switch only a tiny current to generate a 400V pulse to the primary of the standard coil, which then operates as a pulse transformer, rather than as the usual inductive energy storage device.
Its secondary then delivers a huge (and rev independent) voltage to the plugs. I once warned a colleague to keep his hands away from the leads when the engine was running, but he didn't believe me (the first time!).
Performance was vastly improved. The only downside was that adjusting the points became a pain; gently easing the starting handle to open the points would result in the engine instantly starting on that single spark.
In 2012 my restorers removed this "unknown" device, but fortunately I found it in their bin. It's currently awaiting refurbishment, mostly the replacement of time-expired capacitors.
When I re-install it, I'll use a multipole relay to perform the reversion to standard ignition. That puts the emergency changeover onto a dashboard switch, rather than as an under-bonnet re-wire.
Did any other members buy one of these kits?

[ndevans]

Can you post the circuit schematic please?

[svenedin]

I think the half-way house electronic ignition systems that retained the points as a trigger were quite common. It was probably quite a good selling point that they could be reverted to standard points ignition at the flick of a switch.

Lumenition Optronic which has an infra-red optical trigger was launched in 1971. I remember helping my father fit it to his Mercedes as a child in the 1970's.

Stephen


From Holden.co.uk

Lumenition

With 30 years of innovative experience, Lumenition is your key to perfect ignition. Whether it be a simple points replacement for an old classic or engine management on the latest racecar, Lumenition has a system to fit your budget and your needs.

Synonymous with quality ignition products, Lumention's reputation was not earned overnight. It is the result of innovation and commitment to excellence over the past thirty years.

The Lumenition story begins in 1968 when Autocar's then managing director E.H. Ford designed an infrared 'Optronic' trigger to form the basis of a revolutionary electronic ignition system. Thirty years on, this trigger system, unaffected by dirt or distributor shaft wear, is still regarded as the most reliable and accurate available.

Adopted as original equipment by specialist performance car manufacturers, fitted to fleet vehicles and made under license in the U.S. by industry giant TRW, the range went on to include a special commission from the Ministry of Defence: an ignition system for Scorpion tanks. Lumenition was the only manufacturer that could meet their need for an ignition system to withstand the electromagnetic pulse of a nuclear strike!

On a happier note, Lumenition began to concentrate on the racing world. As the science of microprocessors progressed, so did Lumenition, taking advantage of the latest advances in technology. Under the management of E.H. Ford's son Michael, (who was there when a Lumenition system created it's the first spark in Autocar's lab), new products have been introduced. The new products include the laptop controlled Engine Management Systems and accessories such as Lumenition's own throttle bodies, suspension products, meters, specialist silicone HT leads and more."

IMG_9615.jpeg (2.01 MiB) Viewed 19311 times

[philthehill]

I have had Lumenition optronic ignition on my car for many years and think highly of it.

[svenedin]

I have had Lumenition optronic ignition on my car for many years and think highly of it.

Absolutely agree. I did not know it had been used by the MoD and could withstand the electromagnetic pulse of a nuclear bomb.....

It really is a "bombproof" system!

Stephen

[mike1864]

Can you post the circuit schematic please?

Hi Neil
This is the first page of the 9 page manual.
Let me know if you want more (better to PM you than clutter up this topic)

IMG_20251203_0001.jpg (1.44 MiB) Viewed 19299 times

[svenedin]

Although the half-way house type electronic ignition is quite an attractive idea it still suffers from many of the downsides of points. The points still need adjusting periodically (because the points heel wears) and the points still put lateral pressure on the distributor spindle which causes wear of the spindle bushes.

Stephen

[myoldjalopy]

Quote: "The only downside was that adjusting the points became a pain; gently easing the starting handle to open the points would result in the engine instantly starting on that single spark."
I don't understand. Why have the ignition on when adjusting points? And how can a spark reach the plugs if the dizzy cap is off to adjust the points. There is something about this set-up I don't understand...

[mike1864]

Quote: "The only downside was that adjusting the points became a pain; gently easing the starting handle to open the points would result in the engine instantly starting on that single spark."
I don't understand. Why have the ignition on when adjusting points? And how can a spark reach the plugs if the dizzy cap is off to adjust the points. There is something about this set-up I don't understand...

Silly me! You are of course right to be puzzled. It wasn't the point gap tweak that triggered the start; I was in fact checking the static timing (ie the pulley notch versus the three btdc timing cover peaks). The dizzy cap was in place, and the points opening was supposed to be determined via a test bulb (hence ignition ON). But in practice the single opening was signified by the engine bursting into life!
My memory failure is due to last experiencing this (with electronic ignition fitted) forty years ago.

[myoldjalopy]

Ah, I see! Thanks, Mike. I guess the answer to that was to remove the leads from the plugs, or just take the cap off......

[mike1864]

Ah, I see! Thanks, Mike. I guess the answer to that was to remove the leads from the plugs, or just take the cap off......

Yes, that's one solution. But the module's instructions warn against running it with no load (ie the plugs).
Once I'd experienced it, there were other ways of avoiding this instant start; reverting to standard ignition (a 10 second job), or putting a bulb between the battery+ and the points, with the coil out of circuit. This also saved having the ignition on, and the petrol pumping.
In most ways, this over-easy starting was a joy. I'm looking forward to reinstating it; this engine/ignition combination last ran in 1988. Around that time I tried to impress a friend by ignoring the starter knob and just letting the car roll down the slight incline and bringing up the clutch to start it. To my dismay it didn't work. Then it didn't even work on the starter. It was only as I lifted the bonnet that I remembered that two weeks earlier, to prevent theft, I had removed the rotor arm
With the rotor arm back in, we were back in business, establishing that the no-load warning was perhaps pessimistic.
PS Did Neil need the circuit diagram for any particular purpose? The unit would be hard to reproduce now, as - aside from the pcb - the transformer (T1) was highly bespoke.

[ndevans]

PS Did Neil need the circuit diagram for any particular purpose? The unit would be hard to reproduce now, as - aside from the pcb - the transformer (T1) was highly bespoke.

No, I was just interested to see how it was done. Would be grateful if you could post the rest of the doc if not too much trouble. I doubt if there will be any copyright issues now. Not really intending to replicate it, but I'm sure I could come up with something even if not exactly the same.

[svenedin]

One of the ready built systems that retained the points and had an ignition amplifier was made by Sparkrite and in fact you can still buy that system as the Sparkrite SX4000.

https://simonbbc.com/sparkrite-sx4000-u ... er-module/

Stephen

[mike1864]

One of the ready built systems that retained the points and had an ignition amplifier was made by Sparkrite and in fact you can still buy that system as the Sparkrite SX4000.

https://simonbbc.com/sparkrite-sx4000-u ... er-module/

Stephen

A neat-looking unit. I suspect it wasn't on the market in 1973, when I built mine. Its principle seems to be the same as mine, though it's not clear how the Sparkrite "adjusts the dwell angle". Also I'd prefer the switch to be remote, ie near the dashboard. Or mount the whole thing in the parcel shelf?

[Myrtles Man]

The so-called Sparkrite unit currently available has been the subject of consideration on this forum fairly recently viewtopic.php?t=77029&hilit=Sparkrite. The SX 4000 is, apparently, nothing more than a fancy-looking container with very little of worth inside. The Auotoshite people took it apart to check it out a few years ago and what they found therein did not impress them. Unfortunately I can no longer find the piece in question on their forum.

[mike1864]

The so-called Sparkrite unit currently available has been the subject of consideration on this forum fairly recently - check out the following:- https://autoshite.com/topic/30553-the-n ... page/1476/

I can't see any mention of Sparkrite on that link; just a lot of foul-mouthed rants on other subjects (the site name should have been a clue ).

[Myrtles Man]

The so-called Sparkrite unit currently available has been the subject of consideration on this forum fairly recently - check out the following:- https://autoshite.com/topic/30553-the-n ... page/1476/

I can't see any mention of Sparkrite on that link; just a lot of foul-mouthed rants on other subjects (the site name should have been a clue ).

Yes, sorry about that. The link was one I lifted from the earlier discussion on the unit which, at that time, did indeed take you to the analysis of the SX4000. Maybe they've had to remove it for whatever reason.

[mike1864]

The so-called Sparkrite unit currently available has been the subject of consideration on this forum fairly recently - check out the following:- https://autoshite.com/topic/30553-the-n ... page/1476/

I can't see any mention of Sparkrite on that link; just a lot of foul-mouthed rants on other subjects (the site name should have been a clue ).

Yes, sorry about that. The link was one I lifted from the earlier discussion on the unit which, at that time, did indeed take you to the analysis of the SX4000. Maybe they've had to remove it for whatever reason.

I'd actually be suspicious of any compact unit. My one needs its 6" by 4" by 2" Eddybox, as the capacitors need to be big to store the required (ie fat!) charge; you cannae change the laws of physics, cap'n.

[Myrtles Man]

As you obviously have a good understanding of such kit plus first-hand experience you may be interested in pulling apart an SX4000 to confirm/refute Autoshite's verdict; if so you can, for the cost of postage alone, have the one that I bought and briefly fitted to my Moggie, removing it soon after fitting as it made the car run worse!

[mike1864]

As you obviously have a good understanding of such kit plus first-hand experience you may be interested in pulling apart an SX4000 to confirm/refute Autoshite's verdict; if so you can, for the cost of postage alone, have the one that I bought and briefly fitted to my Moggie, removing it soon after fitting as it made the car run worse!

My time time constraints lead me to offering first refusal to Neil