1916 hint for magneto lights

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2011: 1916 hint for magneto lights
Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Kable on Monday, November 21, 2011 - 01:54 am:

In a Motoring page published in 1916 is this hint for Ford owners with the new magneto headlights.

Mr. Steele (Davies and Fehon - the NSW state distributor) gives the following tip to Ford owners who want to crawl over bad roads on high gear, and yet obtain plenty of light from their Standard electric light equipment :-Fix a small press button let into the steering wheel to cut out temporarily the left-hand head-lamp. This is an efficient and exceedingly handy arrangement, and costs only a few shillings. By the above means the low voltage obtaining at slow speed, divided between the two lamps, is turned on to one only-that in front of the driver, and the resultant light is equal to that given by the two lights at a speed of 20 miles per hour There is very little risk of damage to the bulb, as the press-button is operated only when going very slowly on high gear, the current is insufficient for both lamps collectively, but ample for either separately. The careless driver who uses the button when the motor is speeding has only him- self to blame if he burns out a filament and lets himself in for the purchase of a new bulb, costing about 3s. The special switches let into the steering rim makes a very neat job on Mr. Steele's car. The electric horn is similarly operated, both switches being thus handy under the finger tips when steering, and the pearl inlaid switches are quite an embellishment

Any comments John Regan???

Sounds like it might work.

This may be an answer for those who want to keep the magneto lights in use and its a period fix.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George - Cherry Hill New Jersey on Monday, November 21, 2011 - 03:38 am:

Peter.

I can see his logic, in general terms it does work. Yet I also like the 'you burn a bulb, your fault' :-)

One thing I have always looked for on this forum is a general plot of mag output v. rpm, but have never seen :-) (hint)

You can wait for a more real reason from John, I just have the lamp tables memorized as to interchange of nameplate v. buss and what happens. My Dad was Brewster Aircraft Chief Instrument Engineer and in the era had limited bulbs to work with...so from the time I was a pre-teen he felt it was imperative I know the lamp tables, and know how to make resitor packs that looked like a tarantula and still work, and how to solder with 1000% success, and how to mix all of the above together to get any vacumm tube in the box to work in an emergency. Boy did he have insight :-):-):-)but he taught me so many other life skills where the technology still works. I actually don't know squat about electricity, he never got around to self excited fields and how to seat armatures and comms...haha..but hey, your post allowed me to recall that moment on bulbs and do mental slide rule....thanks.

Wired as suggested still has 'issues'...a lamp will do no more than glow up until about 1/2 voltage rating and its first real illumination at 2.1 CP will be at that point. Still better than having to wait twice that for series connected bulbs :-)

Then a 9V Mag output @ ?????rpm/????mph actually is at a 21 CP rating as opposed to 18V on the series connected.

So far, so good!

Now in this proposed idea watch that ?????rpm/????mph...because at 10V, a 200 hour lamp rating is reduced to 66 hours but hey, the CP actually goes to a whopping 30CP :-):-)

At 12V and forgetting to turn it off which is ________rpm/_________mph the filament is screaming and now unstable if it already hasn't vibrated itself to bits, and by 13V the answer is 'what filament' as it just exploded like an old flash camera for sure which is _______rpm________mph.

So the author is correct in what he says, the 'operator' just really needs to know (and have some way of actually knowing) what his mph is :-):-):-) or else the other good thing about the idea is you have a built in spare with a quick rewire :-):-)

OH wait, they sell magne-meters now in 2" size :-):-) but then you need a dash light to see it in the dark, and a mag dash light...oh heck go with a 24v bulb for the dash light and when is finally starts to actually shine and not halo, be ready for the 'pop'...oh heck...just go get a 5 buck (batteries not included) LED push puck light for the dash :-):-):-) a lot easier. sorry for the closing levity...it went through my mind what follow up question might come...and thats where my mind meandered, so thought to share the levity


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hal Davis - SE Georgia on Monday, November 21, 2011 - 07:37 am:

Sounds like a good solution to me. Any suggestions on a period correct switch?

I find it amusing how you accellerate in low gear with really bright lights and then shift into high and the road goes dark. Slowing down for corners gets pretty dark too. It's an amusing characteristic of the Model T. I know you can power the lights from a battery and not have to worry about it, but then this unique characteristic is lost. The fix described above kinda gives the best of both worlds. You still have the unique characteristic, but have a safer, yet period correct, work-around.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Semprez - Templeton, CA on Monday, November 21, 2011 - 10:17 am:

Thanks Peter,

I worry about your "One Eyed Jack" running on mag now. Maybe a rheostat would help, or a second headlight! Any luck finding a replacement?

I do like the thought of pearl inlaid switches embellishing my wheel rim though!

Regards to you and Sally.


Top of pagePrevious messageNext messageBottom of page Link to this message  By KEN PARKER on Monday, November 21, 2011 - 10:28 am:

In order to not involve the rest of your correct system, an easy fix has been suggested. A 12 volt garden battery under the back seat and a period spotlight. I have that setup on a '14 Touring. I bought a RedSpot spotlight on ebay and the battery was $27.

I don't normaly drive at night but last night I drove an hour in the dark in my '25 Touring to get home from my daughter's home. Poor schedule on my part.

Ken in Texas


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Monday, November 21, 2011 - 04:59 pm:

On the "No Dollar Speedster" we wired the guts of a T coil primary in series with two six volt bulbs. Bright and steady lights at virtually all speeds.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John H on Monday, November 21, 2011 - 05:17 pm:

It would certainly work; shorting out one light means the other one gets full voltage.
One light working at with a white hot filament would be much easier to drive with than two lights with red hot filaments.
The only proviso is to use the switch correctly otherwise you run the risk of burning out a bulb and since both are in series then you have no light.
Used correctly, it's certainly a very elegant scheme which keeps the car "correct" except for one wire and a switch added. The existing wiring does not get altered.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George - Cherry Hill New Jersey on Monday, November 21, 2011 - 05:41 pm:

Hal,

No ideas on a fancy switch, but for general era type 'stuff', they still make the aircraft type toggles used in the 20's (close enough for 3 foot rule, anyway :-) )and they are pretty cheap.

I get them at www.led-switch.com

Their K series, and the nice thing is they offer the toggles in just about any internal contact arrangement you might want and they all look the same on the outside for the most part. These are what I do on the hidden turn/flasher/four-way design and then don't feel I have to also hide the switch, it looks ok and period somewhere in the open. I just don't use their little label washer, but think you still could and be 'era'


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erich Bruckner, Vancouver, WA on Monday, November 21, 2011 - 07:10 pm:

Tom,
can you explain or, better, show a quick drawing of that set up? Not sure what is happening with it.

Mechanical things make sense to me but I never did get electricity to make a clear impression on me. (except when I put my finger on it)


Top of pagePrevious messageNext messageBottom of page Link to this message  By John F. Regan on Monday, November 21, 2011 - 08:34 pm:

Typical automotive incandescent lamps have a very narrow operating range. If you take a typical 6V lamp you will find that if you go below its design voltage (usually about 6.3V) by very much it will get really dim pretty quick. If you go above its design voltage it will get very bright pretty quick but its life will be radically shorten very quick. Thus you need to keep it operating at is design voltage for good briteness and long service life. For example a typical 6V bulb operated from a typical 8V battery will find itself connected to over 9V when the battery is charging and the life of the bulb will be reduced to something like 5% or less of its normal design life. That is very short indeed. This is what happens to mag bulbs. The idea of shorting out one bulb certainly would add current to the remaining bulb but the whole concept is an exercise in "guessing" since you don't know how much voltage you have before or after you push the button but if the bulb burns out quick well.... you had too much! It is too dangerous to be driving around at night with any form of headlights that are not reliable - period. If you intend to drive at night with your T - get a battery (6 or 12) and hook up some proper lights both front and rear and then either charge the battery when you get home or rig up some sort of trickle charging to recharge the battery during the day time driving. Make sure your battery is large enough to keep your lights on for awhile. Typical car battery might power your lights until morning if it was fully charged.

Tom's approach of using a T primary coil as a "dimmer coil" is the concept that Ford also used on the cheap car during the T era. The cheap car is the one without a battery and starting system. The dimmer coil idea is to stick a chunk of inductance into the light bulb load so as to have a form of AC resistance (called reactance by us engineering types) that increases with increasing RPM since the AC voltage is also changing frequency as it changes voltage magnitude. That idea of course works as Tom reported but the fact is that at idle you don't have much light power and the Ford dimmer coil version basically acted like a current limiter. Tom's novel idea of using an old T coil primary sounds interesting. Perhaps he will post some data on the lamp current using it. I would be interested in how well it works and what exact lamp he used since this comes up all the time and the typical Ford dimmer coils are not that plentiful although I have a couple of them I keep for experimental purposes. What is neat about Tom's idea is that you can peel turns off the primary rather easily if you pull one out of a T coil so perhaps you could dial in the exact amount of inductance needed for a particular set of bulbs.

Whatever version you use, I personally think it is foolish to wire headlights in series for modern highway driving and I think Tom's approach is not that way but I repeat that you need good lights both coming and going if you intend to drive at night. You are far more likely to be rear ended at night in your slow moving black car with one small tail light with stock 3 cp bulb - not good. Your mileage may vary.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Monday, November 21, 2011 - 09:09 pm:

Of course, John nailed it, as usual. I just ripped the guts out of a T coil with a bad secondary. The primary is about the size of a cigar. I believe the bulbs I used were 21cp #1130. They draw 2.63 amps and are 6.4 volt bulbs, according to the book. As John pointed out, I just unwrapped windings until I got close to 12 volts rms. The other nice thing about the T coil primary is that it doesn't saturate, (magnetically) which would drive it into non-linearity.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Kable on Tuesday, November 22, 2011 - 12:09 am:

Hi John,
Yep have another light ready to put on the Kamper which by the way gets here in Australia tomorrow.
The lights are 1915 Canadian one which are different to the USA ones. So it was a bit hard finding one while over there but I have about 4 on the shelf here.

Did you get my email? I don't have your postal address.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Semprez - Templeton, CA on Tuesday, November 22, 2011 - 02:39 pm:

Hi Peter, I did and sent it to you via MTFCA mail. I'll send it again!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Kable on Sunday, November 27, 2011 - 05:20 pm:

Seem that quite a few Model T owners thought the idea to short out one light was a good idea.

But like anything else it can create problems. Two years after the following was published in a motoring column. Don't forget we are talking RHD here. The left side of the car is called the "near" side (near the gutter) and the right side is called the "Off" side which may be new to some of you.


The headíighls of the Ford, being arranged in series, can be easily " shortcd out " individually, thus leaving the whole of the current available for the one remaining lamp. Many owners of Fords have taken advantage of this, by providing a switch that enables one headlight to be cutout at will. The only disadvantage is that an artificially high voltage is imposed upon the remaining lamp, and this shortens its life,to a considerable extent. Unfortunately, many of those who have adopted the one headlight in this way have chosen to leave the " near " headlight illuminated. Nothing more dangerous to traffic can he imagined. The writer met no less than three such vehicle's one night last, week, all of them with a strong near side, headlight. , The first one met was almost the cause of a collision, for the strong light from the one headlight was almost blinding, and the writer could not see the whole outline of the approaching car at all distinctly. Surely any intelligent schoolboy would have sense enough to know that the "off' side headlight 'should be the light giver I am not firm as to the law in the matter, but believe it to be actionable, when running on one headlight,to use the near light for the purpose. Prompt police action in the matter will probably prevent serious consequences.

John I got the email


Top of pagePrevious messageNext messageBottom of page Link to this message  By Craig Sutton on Sunday, November 27, 2011 - 09:40 pm:

When I win the lottery, I'm going to build a community where the only vehicles permitted are '31 and older. That way, everything moves at the same pace and slightly deranged people like myself can drive around at night with poorly illuminated lamps and hard to see hind ends.

Of course, there would have to be a remote garage so when you got out of the community you would pull your antique into one bay and your modern vehicle out the other.

Hey, if people can live in airparks I can have my T village somewhere!

Craig


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harry Daw on Sunday, November 27, 2011 - 09:59 pm:

When Dad built his 1915, we used a loop of resister wire connected to the headlight on/off switch. We put an alligator clip on the wire that went to the front head lights. He then would find the spot to tap into the resister wire for the driving which he was going to do. Worked well.
At the time I could not find a reastat that would carry enough amperage to use instead of the resister wire.
Today one could probably use a LM317 adjustable voltage regulator (good for 1 amp with heat sink) and use it to control a 2N3055 pass transistor to keep from burning out those expensive mag bulbs.


Posting is currently disabled in this topic. Contact your discussion moderator for more information.
Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration