I didn't measure the resistance. It was 3157 bulb, tail/stop. just clipped on a couple of leads to one filament.
I had tried a variable resistor, I use to simulate sensors, but it couldn't handle the current, and it lost all its "magic smoke"
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| Got a newish ND alternator--How do I make it work? https://slantsix.org/forum/viewtopic.php?t=32521 |
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| Author: | gmader [ Fri Dec 05, 2008 8:14 pm ] |
| Post subject: | test report |
Hi all, Test #1 Quote: connected the voltmeter between the + field terminal on the alt and the battery +, only had about .1 volt drop. That will test all the wireing in the field circuit, except the - side. The voltage drop on that side was less then .1 volt.
results= 15.60 volts from alternator to ground, 15.60 volts from battery to ground. 0 volts different.Test#2 Quote: start the engine, put your voltmeter's positive lead on the battery positive terminal, and your voltmeter's negative lead on the regulator's "IGN" terminal, and see what the voltmeter reads. You'd do this with the stock wires all hooked up, and then with the test leads hooked up.
Results= 15.17 volts (engine was warming up).Test #3 Quote: One test lead between battery (+) or alternator B+ and the regulator's "IGN" terminal (the ring terminal held onto the regulator with a nut or screw), and another test lead between the regulator's "FLD" terminal and the ungrounded field terminal on the alternator. Remove the original wires and tape off the regulator IGN wire before you attach the test leads. From what I am seeing, I think it changed a little bit, due to the motor warming up, but it still seemed(felt?) like it was getting more juice. It is consistently staying at 15 volts or higher. |
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| Author: | SlantSixDan [ Fri Dec 05, 2008 8:58 pm ] |
| Post subject: | |
Still too high. Very strange! Let's see what happens with CS' adjustable-regulator experiment. |
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| Author: | gmader [ Fri Dec 05, 2008 9:19 pm ] |
| Post subject: | |
I have a bazillion resistors here. Charrlie, do you have any guesses as to what resistance your small light bulb is? I can try the resistor trick, and see if that gets close. Thanks, G |
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| Author: | Charrlie_S [ Sat Dec 06, 2008 4:23 am ] |
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I didn't measure the resistance. It was 3157 bulb, tail/stop. just clipped on a couple of leads to one filament. I had tried a variable resistor, I use to simulate sensors, but it couldn't handle the current, and it lost all its "magic smoke"
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| Author: | SlantSixDan [ Sat Dec 06, 2008 7:27 am ] |
| Post subject: | |
The 3157 bulb has two filaments: the "major" (bright) one rated 26.9 watts at 12.8 volts, and the "minor" (dim) one rated 8.26 watts at 14.0 volts. These are nominal ratings; production values are nowhere near as precise as with calibrated resistors. Nevertheless, let's go with those values. "Twinkle, twinkle, little star; power equals I-squared R": Major filament 26.9 = [(2.1)(2.1)]R 26.9 = 4.41R R = 6.1Ω Minor filament 8.26 = [(0.59)(0.59)]R 8.26 = 0.3481R R = 23.7Ω Of course, using a bulb as a resistor is a handy test, but not a good fix; as soon as the bulb burns out, you lose all charging. |
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| Author: | gmader [ Sat Dec 06, 2008 8:27 am ] |
| Post subject: | |
Thanks for the physics refresher, Dan. I am wondering how many amps it took to burn out the Variable resistor that Charrlie was using? I didn't think that the field wire current would be very high. [EDIT] In reading back and checking, would the field connection really draw 7 amps? That seems pretty high. [/EDIT] I will start digging around in my box o' resistors, and see what I have. Thanks again! G |
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| Author: | Charrlie_S [ Sat Dec 06, 2008 10:31 am ] |
| Post subject: | |
Quote: Thanks for the physics refresher, Dan. I am wondering how many amps it took to burn out the Variable resistor that Charrlie was using? I didn't think that the field wire current would be very high.
If I remember correctly the current was over 2, but less then 4 amps. The resister was similar to a volumm control. No current handling capacity.[EDIT] In reading back and checking, would the field connection really draw 7 amps? That seems pretty high. [/EDIT] I will start digging around in my box o' resistors, and see what I have. Thanks again! G The field draw, would depend on the design of the alt. It is possible the altnator for use with the adj regulator is for a commercial truck or police/fire vehicle, and has a different internal design. When I was building fire trucks, the alternators all were 200 amps minimum, with adj regulators. Part of the preship inspection/setup was to full load the electrical system, and adj the regulator for 13.8 to 14.2 volts. |
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| Author: | gmader [ Sat Dec 06, 2008 11:35 am ] |
| Post subject: | |
Next experiment- Resistors in the field circuit I put a 10 Ohm (10 Watt) power resistor in the circuit. Cold engine Voltage at 13.3 Volts. I might wire this up on a board, and go with this for now. That is pretty close. If I could find a 7 Ohm power resistor, I would try that, and see if I could sneak up on 14 volts. |
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| Author: | SlantSixDan [ Sat Dec 06, 2008 12:28 pm ] |
| Post subject: | |
13.3 is lower than you want. Keep in mind that the charging voltage temperature compensation depends on ambient temperature, not engine temperature, as a proxy for battery temperature, which is what really matters. As the engine gets warm it'll heat up the engine compartment and battery. You should shoot for the following (temperature right at the voltage regulator, but not touching it): 0° to 50° F: 14.45 to 14.95V 50° to 100°F: 13.85 to 14.45V 100°F to 150°F: 13.75 to 13.85V 150°F to 200°F: 13.75V Once you get your resistor selection roughed-in to get you into the right ballpark, try heating the regulator with a hair dryer while you watch the voltage across the battery on your voltmeter, to make sure you have roughly this kind of temperature/voltage curve. |
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| Author: | gmader [ Sat Dec 06, 2008 12:43 pm ] |
| Post subject: | |
Agreed, 10 ohms is too much. I am getting 12.6 volts warmed up. I gotta find a 5 ohm power resistor around here..... G |
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| Author: | emsvitil [ Sat Dec 06, 2008 1:28 pm ] |
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What happens to the voltage when you put a load on the system (lights, fans,etc.) ? |
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| Author: | Charrlie_S [ Tue Dec 09, 2008 10:08 am ] |
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Just called to check on my adj VR. It was back ordered, but Weitzels should have it in a couple of days. It will then be shipped to me. I should have it within a week. |
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| Author: | gmader [ Sat Dec 13, 2008 1:59 pm ] |
| Post subject: | Now it is working as expected? |
Hi all, I got back to the project today. After trying the hair dryer trick, and a bunch of different resistors, I am back to square one. Well warmed up, without a resistor, and after hair dryering the VR, I am getting 13.79 volts out of the alternator. I need to keep monitoring this, obviously..... |
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| Author: | SlantSixDan [ Sat Dec 13, 2008 2:00 pm ] |
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I'm kinda curious to know if you've tried more than just the one regulator, GMader. |
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| Author: | gmader [ Sat Dec 13, 2008 2:28 pm ] |
| Post subject: | |
2nd test, after a good test drive, and well warmed up. 13.3 V, without any resistors. Same Voltage Regulator, no changes there. I am using the same multimeter, in the same way. I did go through all the connections completely. Maybe I inadvertently fixed a bad connection, or ground. I give. 
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