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Search took 0.00 seconds. Search: Posts Made By: B_man_Al
Forum: Early V8 (1932-53) 08-12-2013, 08:18 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Looks fine to me. Be sure to check the actual numbers with measurements to be sure.

With the engine off, the dissipation in the loom resistor will be about 25W (6.16V x 4.1A) …. That’s quite a lot...
Forum: Early V8 (1932-53) 08-11-2013, 05:29 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Here's the requested slide
Forum: Early V8 (1932-53) 08-11-2013, 05:27 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Ideally the voltage at (across) the points would be zero, if they were a "perfect" switch, with 0 ohms resistance. The coil voltage will not impact the voltage at the points significantly. I put a...
Forum: Early V8 (1932-53) 08-11-2013, 01:12 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

AS requested for 1.5 ohm ballast, 1.5 ohm coil, and no loom resistor. Added engine running case with points closed for peak voltages and currents. These need to be averaged by the dwell to get...
Forum: Early V8 (1932-53) 08-10-2013, 05:48 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

As requested, for .7 and 1.4 ohm ballast ... slight modification on the first one from post 82. Current drops from 3.3 to 2.8A with ballast change
Forum: Early V8 (1932-53) 08-10-2013, 09:58 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Attached is what you should get for voltages and currents for the 12v, engine off case with R loom=1.5, R ballast = .7, R coil = 1.4. If you want other cases let me know.
Forum: Early V8 (1932-53) 08-09-2013, 08:02 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Gasoline ...

Thanks for your kind words !

In your original configuration, .7 ballast, .7 coil, and a wiring resistance of 1.5, the "engine off" current would be 12/(1.5 +.7+.7)=4.1 A.

This...
Forum: Early V8 (1932-53) 08-09-2013, 07:41 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Hi George ...

I just did the experiment I suggested to you in post 76 with my model B, 1.5 ohm ballast, 1.5 ohm coil. Here's what I got using a digital multimeter.

1-Ignition off: V across...
Forum: Early V8 (1932-53) 08-09-2013, 04:20 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

George ..

Here's a test you can do to illustrate what I'm trying to say. Make the measurement you usually do with the car running. Clip the meter across the ballast resistor and measure the...
Forum: Early V8 (1932-53) 08-09-2013, 12:00 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

George .... your right about 1.5 ohms x 2 amps being 3 V . That's called ohms law. But what you are missing is the fact that when the car is running, the 2A is only flowing while the points are...
Forum: Early V8 (1932-53) 08-09-2013, 07:22 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Gasoline … hope you dont glaze over here, it’s a long one!

I think the digital meter is giving you false readings when the car is running. This is because the meter is set to DC (I presume) ,...
Forum: Early V8 (1932-53) 08-08-2013, 03:00 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Gasoline ...A couple questions:

1- Are your key on/ engine off measurements in ohms or volts? It says ohms.

2- What is the measured resistance of the ballast resistor and the coil measured...
Forum: Early V8 (1932-53) 08-08-2013, 06:36 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

The voltage across the coil is determined by both the ballast resistor and the coil resistance. If the ballast resistor is the same in both cases, the voltage across the coil will be less for a lower...
Forum: Early V8 (1932-53) 08-04-2013, 08:50 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Hi George ...

I just went to the MACS website. Typed in 32 ford and the A12001 came up as the resistor to use for a stock model B coil when used for 12v operation.
...
Forum: Early V8 (1932-53) 08-03-2013, 01:15 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Just to keep a good thread going, and to answer George. My 32 4 cylinder with the MACS A12001 ballast resistor gives a current of 4A when not running and just turned on. (Ballast resistor cold)....
Forum: Early V8 (1932-53) 07-31-2013, 11:43 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Hi George ...

My 8BA is not on the road yet, so its only running in the garage occasionally. This is the one I did the measurements on. However I converted my 4 cyl Model B to 12v the same way in...
Forum: Early V8 (1932-53) 07-31-2013, 07:46 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

In post 36 I tried to explain what I did to determine the current and voltages associated with my 8BA coil/external ballast resistor combination on a 12V system. Key to the whole thing are two...
Forum: Early V8 (1932-53) 07-31-2013, 07:14 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Tom .. Yes the coil resistance will go up with temperature as I posted in post #34. But because the ballast resistor is made from a special steel wire, it will increase a lot faster with temperature...
Forum: Early V8 (1932-53) 07-31-2013, 06:12 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

BillM … thanks for the link to the coil site. Well I guess I got to eat some crow here. Didn't know that coils designed to work without a ballast resistor, have them built in! Makes sense though, to...
Forum: Early V8 (1932-53) 07-30-2013, 07:47 PM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

Below are some results I measured on my 8BA with a 6V coil, and a nominal 1 ohm ballast resistor. It has been converted to 12V.

I found the best way to estimate the primary current was by adding...
Forum: Early V8 (1932-53) 07-30-2013, 06:26 AM
Replies: 92
Views: 56,436
Posted By B_man_Al
Re: Mallory tech answer to coil/ballast ?

BillM ...

I'm not sure of the tempco for the ballast resistor, but any coil which is wound with copper wire (all of them I believe) has a positive tempco of .293 % per degree C. Check the spec on...
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