What, if any, is the advantage of a master vibrator? I have a 1914.
One coil, 1/4 the problems.
Of course, if that one coil fails, youre walking home instead of limping back on three....
Basical on set of points
Hmmm, I should wake my wife for this one!
I just sent you a PM.
Marty, I am about the biggest Dummy when it comes to things electrical, but I think I have read on here that it has something to do with the early style coils. I'm sure someone(anyone!) that has more info than(not THEN)me on here will chime in! Dave
The purpose of the master vibrator is to eliminate the variation in performance in early coils, which by their point design are difficult to adjust for consistent firing.
To use the master vibrator, the points for all four coils are bridged out, and the master vibrator, being in series with the supply to the coils, substitutes with its one set of points all four of the previously used coil points. Thus there is only one points adjustment required and all coils will fire the same.
Once the later designed points became available with proper cushion spring design, the master vibrator was made redundant.
It started as a challenge and it became a little passion. Some one said: "You can't make it run properly."
Since 2013 I am running two model T's with a master coil. There is no difference in driving with a good working master coil or driving with four good coils.
Sometimes I call it: "The 1910 Electronic Ignition for the Model T."
In total I have 9 working Master coils, three are K&W made but have different switches or the inner box is different.
The best running are the K&W coils because they use all the well know coil points.
The other coils are J&B; New York Coils; Menominee; R.C. Wells coils and Chicago Coils.
As said before the master coils were made in the early 1910s to eliminate the difficulty to get the four coils set up the same way and get a smooth running engine. The reason for that was the way the coil point were made.
As soon as K&W came with the point with cushion spring the master coils became redundant and disappeared.
I start the rebuild of the M.C. by taking it apart and clean all the brown stone like stuff out of the box. The capacitor is replaced by one
Fun Project offers and the point are redone or replaced if available.
At the original coils in the car you need to bridge the points.
To set them right I use a HCCT and try to set them as close as I can to the normal coil setting: Single spark and a little less as 1.3Amp.
Only the K&W M.C.s give a single spark the other are set at the strongest spark but not over 1.3Amp .
To run the coils in the cars I made a wire loom that is easy to replace by the original wiring and connect the battery and the M.C. in a similar way as the original wiring loom at the coil box.
One wire is connected to the B post of the M.C. and the battery, an other wire between the M post and the Magneto output, and the third wire between the C post on the M.C. and the coil box.
The coil box need to be disconnected from the original wiring loom.
In each car I have four good coil for the case the M.C. fails, Till now, about 10,000 miles later, I never had to replace one.
John H is 100% correct in his reply above.
And what's old is new again. The E-Timer electronic ignition works on essentially the same principal as the Master Vibrator. All 4 coils points are bridged out (shorted) and the E-Timer repeatedly charges and fires the coil. Only there are NO coil point adjustments required for all coils to fire the same.
Thanks all! Basically it sounds like if I have good, well tuned coils, a master timer is not needed. My 14 runs great with the 4 rebuilt, six screw brass-topped coils.
With a master timer, do you get the same familiar buzzing? I like that sound, It's iconic.
The buzzing is there but only when running on battery, on magneto it is hard to hear and come out of the M.C.
The buzzing is more a flapper noise that came out of my coil box because I first left the old contact points on the coils. Two seasons ago I took out the under contact bridges on the four coils. Now it sound like a heart beat, steady and calm.