9 Terminal Lucas Regulator Replacement Project

[Kameron M]

Hello, Kam here. I'm new. I'm also restoring TC5086. She is coming along slowly slowly, but well.
I'm a computer engineering student (well, almost done), and I do a lot of Electrical Engineering stuff in my spare time, and in my work. Electron pushing is my thing.

Lucas stuff horrifies me. I am de-lucasing the entire car. This is a combination of my desire to A- Not have anything Lucas. B- Not have anyting Lucas. C- because I can. D- Because I wanna.

Anyway, I have been awake for the past... dunno, 60 hours at a hackathon event, and my project (which lost -- possibly because no one understood it) was reverse engineering and subsequently re-designing the Lucas 9 terminal regulator.

Presently, the status of the project is as follows:
I was poured through the "documentation" about the regulator, and after doing a lot of experimentation- I was able to figure out how it works-- at least enough.

I designed a circuit, then simplified it, using a single inexpensive analog electric chip which monitors the output of the generator and can activate or de-activate relays depending on various conditions.

The above circuit was then modified such that it could be used on the positive ground system and monitor the negative voltages the car uses.

The circuit was then tweaked and made conveniently adjustable for battery voltage that it will regulate towards, drop in/drop out voltage of the cutout relay.

Presently my regulator uses two $3.95 auto relays (which are a little slow)- I might work now on a solid-state regulator with transistors-- which won't tick, or a faster relay (which will tick).

I then went and fixed what I thought was a horrible problem, that the dash Ign warning light- if it burns out will cause the car to not have electricity. This is no longer the case, but the ign warning light still works, and could now also be replaced with an LED, or a lower draw light bulb (like a 28 volt bulb for longer life)

The new circuit draws a lot less power than the original regulator, and is also significantly less expensive. My prototype has about $12 worth of electronics in it. In total, it is a complete drop-in replacement for the lucas unit, and is pin-for-pin compatible with the 9-terminal regulator as original.

I plan on continuing on the design of this all to make a regulator that works a little bit faster than my circuit does now. I am considering designing a PCB (printed circuit board), and possibly selling it.

I might make this as a simple bag of parts you solder up yourself style kit, or an assembled product. Currently, the amount of electronics used was small enough that it would be super easy to fit it in a housing styled to look like the original, but having that made would require a significant consumer interest for me to be able to do it, it would be expensive.

Anyway, I would like to gather the TA/TB/TC community's thoughts on the subject, and I will keep posting here about this project, and my TC as well as things move right along.

Here's my prototype (not in box yet) happily clicking away on video.
I had it configured to output ~9v here because my matco impact driver did not have enough oomph to make reasonable amounts of 12 v output on the generator.

https://www.youtube.com/watch?v=N4ptALA_s8M

<iframe width="560" height="315" src="https://www.youtube.com/embed/N4ptALA_s8M" frameborder="0" allowfullscreen></iframe>

[Steve Simmons]

Welcome, Kam. I applaud you efforts with this project and there are those who run solid state conversions. Personally, I am not one of them. The way I figure it is that the original control box when kept in regular use will last for decades. Case in point, I dug an old factory refurbished (early 1950's I believe) 9-post control box out of a closet and put it into my car 12 years ago. Still runs flawlessly!

If the mechanical control box gives you trouble, the car continues to run. With electronics you have multiple potential issues, including high heat, vibration and varying voltages in the system which aren't as gentle on electronic devices as they are on mechanical ones. And if the electronic item has an issue, you're dead in the fast lane with no chance of a speedy repair. If you know what you're doing, you can repair the original part on the side of the road with a screwdriver and a nail file, should it have a problem.

Where I see electronic parts having an advantage is on cars that aren't driven regularly. In this case, contact points can corrode and will require a bit of fiddling now and then to keep them running at their best. But if the car is kept more as a showpiece than a driver, then it probably doesn't matter anyway. I'm sure some will disagree with my views.

I don't want to dissuade you, rather quite the opposite. But I'm a bit of a luddite when it comes to old cars. I just like 'em old. My wife has a modern thing, in case I ever get tired of driving mechanical contraptions. (fat chance!)

Now if I WERE to go electronic, I would want it to look 100% original from the outside. Not that I'm a purist by any means, but I don't like looking at modern parts when I lift the bonnet even if I know they are in there. I have a few, but you'd never know it.

Do keep us updated on your progress. Nice to see fresh ideas on old machines.

[jamesmdavis]

There is currently a solid state replacement digital regulator available in the original housing. Please see http://www.vintagemecha-tronics.com It is available for pos and neg ground, RF95, RB106, or RB340 regulators.

Jim Davis
TC 7225

[stephen stierman]

"Lucas stuff horrifies me. I am de-lucasing the entire car."

Sorry to hear that and since most of the electrical stuff on TC2911 still has 1947 stamped on it, I feel it has served pretty well. Can't say the same for the throw away electronic junk on modern cars that takes a special code reader to diagnose and then cannot be fixed but must be replaced. You know I can rebuild my fuel pump or windshield washer motor, of if my regulator goes bad I can transplant the guts from a newer unit inside of it. I suspect that long after we are gone if some bright fellow can read a greasy thumb printed Bentley manual he will be able to figure out how to keep that TC running for a lot longer. There are still a lot of Model A's around and plenty of replacement parts. Probably won't be able to do that with a new Honda. Just sayn'.

[Steve Simmons]

There's a guy in our TC club whose father back in England used to buy and sell cars. The first thing he would do when he got an American car was to strip the electrical system, throw it away and install Lucas parts instead.

Lucas parts are of high quality and I agree, most of it will literally last 100 years if kept in good order. There is no car made today that will still have its original parts, let alone exist, in 100 years unless it's a museum piece.

By the way... what ticking noise? The only ticking should be from the fuel pump!

[Kameron M]

By de-lucasing, for the most part I am running all new High voltage rated wire, adding fuses in a fuse box, going for a starter solenoid instead of the pull-cable arrangement, building a current-mirror circuit such that the ammeter will function as original but without all the electricity for the car and from the generator running through it.

Also, someone already did 80 percent of the work for me by simply chopping through all the wires when they took this car apart. With a hacksaw. The only original parts I have remaining are the coil, the corroded regulator, two rotary switches, and the dash instrumentation.

I think it goes without saying that the electrical system has a few flaws. Off the top of my head these are ones I can think of:
Unfused electric lines running long distances.
Horn - 10-15 amps, Headlight - 10 amps are powered directly through the switches on the dash. As are components connected to the ignition keyswitch.
The incandescent dash lights are regulated with a wirewound resistor- Instead of using a higher voltage bulb.

Most of my planned improvements center around countering these issues with fuses, relays, and better wire.

What I am not doing is making my entire car run off of a microcontroller.

That brings me to what I noticed on the solid-state controller box. First of all, it appears to cost about as much as the original regulator. It also appears to be using an arduino microcontroller that is powered off of ~5v. This kind of electrical device, admittedly, would not be particularly compliant to changing voltages.

I don't think I would ever do it that way, for a number of reasons.
1- parts cost.
2- Arduinos are not very well known for their reliability in the ultra-long term
3- it doesn't look adjustable
4- if I were to suspect, the Arduino is using ADC's to sample the voltages in the car, and then making the mosfets change state accordingly in some sort of P-I-D control (or maybe just P). While this would surely work, it is unnecessarily complicated.

I'm not really looking to make a huge ammount of money for myself, I mostly do this for fun. For anyone that likes this sort of thing, i've put my annotated schematic up to show how I made this thing work with two relays and $15 or less worth of parts.

[Duncan M]

Kam-
I did something similar when the ignition points condenser finally failed after 66 years. Lucas of course. Check out my thread about 6 down from this one on condenser alternative. I agree with above on not being able to tell. The particular electronic chip design was chosen because it can easily be hidden inside the distributor cap.

[Warmuthb]

go take a look see at: www.worldphaco.net. this chap has added a few items and made some mods which fit in the original housing. I have done several 5 post regs and they work well....same mods for a 9 post. Uses the original points set-up, just uses a transistor, diode, and a resistor.

Brian

[Gene Gillam]

Welcome Kam...

And I'm on your side...modernize while keeping the original appearance. No one will know unless you tell them.

Gene

P.S. - Please tell me your TC isn't really purple

[Kameron M]

Neat use of a transistor to shunt field current around the contacts instead of through them. How delightful. I might try that fix on my RB-95 to see how well it works and leave it be.

I have a few different color combinations I have been drawing up, and one of them will be eventually selected for my TC. Presently white base and purple fenders and running boards is on the top of the list. Black and purple is also being evaluated, perhaps.

Sure, this isn't *exactly* an original color combination that the factory offered, but since when is that a necessity of car ownership? If someone after me doesn't like it, they can repaint her in any color they like, for sure.

[Marv]

Uh-Oh Kam, Now you've done it!!! You've offended the O.P. (Originality Police) big time with the color combinations you're playing with. They might have turned their heads a bit when you were attacking poor old Lucas but now this... Purple fenders on a TC!!! Sacrilege!

Marv TC5141

[frenchblatter]

Kam. It's a pity you weren't around 80 years ago when the Lucas regulator was first made. You'd be as rich as Bill Gates now if you'd have done this then.

The later Lucas stuff was bad, it was built to a price. But the pre 1960's stuff was good and many 60 year old components are still working. Of course they're not as efficient as modern stuff, but as said above will the new stuff be working in 60 years?

I would not call myself a purist but I am rebuilding my TC as close to original as possible. Why? Well what's the point of modernising it, may as well buy an MG B or TF. No, originality is what makes one car more valuable than a non original. So the market dictates that mine will be as original as possible.

[Kameron M]

I figured this topic of discussion would come up at some point. Honestly though, must monocles really fly out of eye sockets if I paint my car a non-original two tone?

There are a few of them out there in the world, and I think it looks pretty good the way the body lines work out.

What I'm NOT doing is handing some craigslist joe 50 bucks to airbrush flames on the side of it. That would look purely awful

[Kameron M]

Kam. It's a pity you weren't around 80 years ago when the Lucas regulator was first made. You'd be as rich as Bill Gates now if you'd have done this then.

The later Lucas stuff was bad, it was built to a price. But the pre 1960's stuff was good and many 60 year old components are still working. Of course they're not as efficient as modern stuff, but as said above will the new stuff be working in 60 years?

I would not call myself a purist but I am rebuilding my TC as close to original as possible. Why? Well what's the point of modernising it, may as well buy an MG B or TF. No, originality is what makes one car more valuable than a non original. So the market dictates that mine will be as original as possible.

I'm leaving be what I can. Some things I can't leave be. Some things that I have which are original are simply broken.
I'm trying to leave be anything that can't be turned back the way it was. No new holes, no welding crap on, etc.

The lucas switchgear is pretty mediocre. The rotary switches are very badly designed and 'wear in' such that there are click detents that shouldn't be. In either case, I think it is pretty foolish to run 6, 12, 15 amp currents through a 60 year old switch on the dash when it is so eassssy to put in a relay, and I think likewise that it is a fool stunt to not put in some fuses where they ought be but weren't originally.

And, like I said, someone previous to me took the liberty of hacksawing through all my wires, so if I'm redoing it all, I might as well use some modern safety conventions and things that weren't in place back then such that the chance of say... an electrical fire is lower.

Admittedly, the RB95 is a pretty amazing piece of electromechanical engineering. The guys that built that really REALLY knew what they were doing. We have transistors now. Transistors, comparators, microchips, all that stuff simply provides a better solution to the problem that was solved back then with a buzzy box.

I am looking into doing the single transistor modification to my buzzy box, though, it sounds like a neat workaround and improvement. On that note, does anyone know how I can get new points to service it? Mine is severely blackened.

[stephen stierman]

So what someone cut your old harness big deal. Why don't you just buy a new one from any number of sources and add a few fuses as some of us have done and install it? You are going to rewire it yourself, so will the wires be color coded and will there be a schematic so that when you decide to sell it in a few years the next owners will be able to figure out what you have done? There is nothing wrong with the switch gear, my stuff has lasted close to 70 years and still operates. If need be it can be disassembled and repaired. You did away with the pull starter!? Why, apparently you aren't aware that some of this stuff has a great degree of charm associated with it and is valued by TC owners. I suspect you will want to do away with the original cat eye lamps if you have them and install halogens so you can see while doing all that night driving. Perhaps an engine and gearbox from a Miata would be best since you haven't gotten into that yet and found that the originals aren't very powerful and leak oil? And what is wrong with the several original color combinations that were tasteful and available from the factory. Sorry but I don't see your choices as an improvement. I don't mean to be rude, but I spent too much time and money trying to return my car to a semblance of how it left the factory after 60 years of people trying to "improve or fix" it. Since I am just a caretaker, I hope the people that have it after I am gone will be likewise as considerate of nice vintage automobile

[frenchblatter]

Stephen, I think you've summed it really well, for all of us.

Thank you.

[stephen stierman]

I believe you should gain an appreciation of how and why they did things a certain way when these cars were built, there is a wonderful historical significance to be found, there are never going to be any more. Look at the folks on this board who have delved into the minutia of why things were done a certain way, an interest to all of us. Anyone can change something and put a modern widget in place of an old Lucas switch, is this an improvement? Is that what owning these cars is about? He!! no, not for me and probably for most of us. I don't want to see a street rod wiring kit or home made wires where those pretty tracer colored original wires should be, because someone thinks it is better, it isn't. My car is not perfectly original, the vast majority are not. I have a spin on filter and a real air filter hidden in that canister, and brake lights and turn signals on both sides. But I spent a lot of time putting the stuff that looks right back on the car after studying the photos in books and visiting others. Color and trim are individual choices, I understand that, but the factory did a pretty good job with what they had and they look right on the car. There is not a bad line on a TC and the right color combinations are an asset, unfortunately not everyone has the best taste even if they think they do. I apologize if I have offended..............

[Duncan M]

Kam-

With mod's you tend to end up with something not very reliable, or desirable. Trick is to know what you can get away with. A hidden relay to take the warmth off a dash switch is typical, and works good. Also, there has been talk of harvesting the regulator and/or cutout from the later Lucas 5 post. Though those are getting harder to find that are not cheap junk from wherever. Not to mention the cool date code on the regulator and dynamo, and elsewhere.

[Kameron M]

Pooh! I know, I'll do an LS swap!

Kidding.

Yes, I did away with my pull starter. Mine was quite in a bad way, and I found it difficult to source a replacement. If someone wants to replace the pull starter, or I do when there is more surplus cash available surely they would be able to source the appropriate parts to make it so. For the moment, a Mallory type push pull switch- and solenoid were substituted.

I don't have cat-eye lamps, nor do I have an extra grand to source them. If I could, I would. The chrome headlights which I happen to have do not have the original rings but 7 inch adapters. I tried my darndest to find a replacement vintage lens, but to little avail.

I think, there is a growing misconception here of my intentions. In hopes of not starting any hostilities between me and the vintage car community, allow me to concisely explain what I have, who I am, and what I am trying to do.

I'm a 21 year old college student.

I saved up for a number of years to purchase what has been a dream car of mine for at least 10 years
I found one, in a trailer, with *most* of the major components, intact that was a failed attempt at restoration.
I bought it, and have been re-assembling since for the past 6 months, in attempt to create a running example.

When it comes to anything that is broken or missing (e.g. wiring components, electrical stuff, headlamps, small mechanical bits and pieces, etcetera), I evaluate a number of criterion when it comes to working a solution out

1- Can I purchase the original part at reasonable cost, for what it does?
2- If that isn't the case, which often is so at my state of things, is it possible to fashion a considerably less expensive replacement which preforms the function I need?
3- If 2, can this replacement be fashioned to the car without cutting, drilling, welding, or tapping?
When it gets to 3, I evaluate how well I can do any particular task, and then look back to 1 to see what exactly can be done.

I don't ever intend on selling this car. Invariably, of course, it might get passed on eventually. When I have more funds to put in this thing, surely then I can afford things like absolutely correct switchgear, the right starter put in, a new set of Girling Dampers, an engine rebuild from the bottom-up, the correct carburetor linkages.

Every time I put a part in, I think: can this be put back together like it was, or to look like it was, someday by me or somebody else?

Sure, from an end-point analysis of market value and all that, there is an advantage to a concours grade restoration. Every little bit as it was, valve caps all correct to period, everything meticulously cleaned to grade with a toothbrush.

Right now, I'm trying to make TC5086 into a car again. Presently, it isn't a car.

Is the frame going to rust on me, is the engine in good enough order to run, do I have fuel, water, spark, and oil? Is the suspension in a condition that won't be either dangerous or destructive to the components? Can the body be preserved?

These are the sort of questions I'm up against.

From my background in Electrical Engineering and electronics, I find the rewiring and general tweaking of the electrical system to be enjoyable. Positive ground systems are odd, and fun. For the most part I'm following along with the original wiring diagrams, even using an SU fuel pump. I'm using modern connectors and the mallory switches which I personally like, even if they aren't original- they fit in the original holes.

I'm not cramming in a digital dash, or a Miata engine, and I think I should take a little offense at the analogy.

I don't intend on selling something which I have been infatuated with for 10+ years.

Right now, I'm a young kid, on a shoestring budget, laboring rather tirelessly to save a car that was otherwise left-- quite alone in a trailer. Concours or not, you can understand that cars are meant to be driven.

I know for a fact that people with money have done a lot worse:

https://www.youtube.com/watch?v=oRx6LqWTE-I

[Duncan M]

Kam-
Many people prefer their TC's bone stock. It takes some talent and skill to set up a TC properly in original form.