12V 60A car battery , maybe dead?

[Mars67]

Thanks Groundloop

That is a great idea! I was thinking along the same lines but was worried if the insulation on the wires might not be damaged. I'm not sure how easily that could happen. I was thinking of mounting the bobbins with the shaft around which the bobbing spins horizontally to the plane of the disk with the feed end directly over the hole to minimise the risk of chafing. I just don't know how I am going to ensure enough tension on the bobbins for controlled feed. Perhaps use small machine screws as shafts and just tighten them. I will experiment with some ideas and post here. I also need to find something to use as bobbins.

[Mars67]

I made a wire winder out of Plexiglas that I had lying around. I mounted the bobbins with the axis vertically to the plane of the disk as suggested by Groundloop because the disc is a little too small to make it practical and I was in a hurry to get going. As I suspected I was going to have some issues with feeding the wire off the bobbins and it was the case so I ended up feeding a meter or two and then winding it up with my battery drill/screwdriver as I was going along. I had the drill set to screwdriver setting. You need to do this whilst concentrating on the tightness of the winds and trying to keep you fingers out the way of the spinning bobbins. The end product, whilst not professional, should work ok.

I did not know what to use and decided to try using the spools solder wire is supplied on. It turns out that 78 meters of 1mm Magnetic wire fills up the spool almost completely. I simply measured off 78 meters of wire and then ran it onto the spool with my drill. I found that the spool I took the most trouble to roll on the wire slowly and neatly also fed the best in my spinning tool.

I then rolled the twisted wire onto a 2lt soda bottle with an od of 100mm by hand. This was quick but did not come out as neatly as I would have liked. It would be better to make some spooling tool like another post in this thread. I think it should be ok though. I made off the ends of the coils and tested them for continuity. The coils are fine with no short. Unfortunately I do not have a means to measure the inductance of the coils.

I decided on 75 meters as per another post on this thread but used 78 meters to account for the wire shrinking due to winding it up. It ended up a little over 75 meters. The twisted wire only made 184 turns and not 200 as specified. Perhaps because I rolled it a little too thick as the od is slightly over 120mm. I wonder what impact this will have on the circuit?

The only thing I still need is a heat sink for the TO3 transistor and then I can test the circuit. My supplier was out of stock. I am going to build the circuit this week and will hopefully be able to test it soon.

Here are some pics of the tool as well as the completed coil.

[Groundloop]

I made a wire winder out of Plexiglas that I had lying around. I mounted the bobbins with the axis vertically to the plane of the disk as suggested by Groundloop because the disc is a little too small to make it practical and I was in a hurry to get going. As I suspected I was going to have some issues with feeding the wire off the bobbins and it was the case so I ended up feeding a meter or two and then winding it up with my battery drill/screwdriver as I was going along. I had the drill set to screwdriver setting. You need to do this whilst concentrating on the tightness of the winds and trying to keep you fingers out the way of the spinning bobbins. The end product, whilst not professional, should work ok.

I did not know what to use and decided to try using the spools solder wire is supplied on. It turns out that 78 meters of 1mm Magnetic wire fills up the spool almost completely. I simply measured off 78 meters of wire and then ran it onto the spool with my drill. I found that the spool I took the most trouble to roll on the wire slowly and neatly also fed the best in my spinning tool.

I then rolled the twisted wire onto a 2lt soda bottle with an od of 100mm by hand. This was quick but did not come out as neatly as I would have liked. It would be better to make some spooling tool like another post in this thread. I think it should be ok though. I made off the ends of the coils and tested them for continuity. The coils are fine with no short. Unfortunately I do not have a means to measure the inductance of the coils.

I decided on 75 meters as per another post on this thread but used 78 meters to account for the wire shrinking due to winding it up. It ended up a little over 75 meters. The twisted wire only made 184 turns and not 200 as specified. Perhaps because I rolled it a little too thick as the od is slightly over 120mm. I wonder what impact this will have on the circuit?

The only thing I still need is a heat sink for the TO3 transistor and then I can test the circuit. My supplier was out of stock. I am going to build the circuit this week and will hopefully be able to test it soon.

Here are some pics of the tool as well as the completed coil.

Mars67,

A very nice build to solve the coil twisting problem. :-)

The circuit is not critical in any way and your 184 turns will do just fine in the circuit.

Looking forward to see you completed circuit.

Regards,
GL.

[Mars67]

I finished building the circuit on Tuesday and eventually had time to test it last night. Success!!! Here are some pictures of my progress to date.

I then tested it the charger on a 6V battery that just to see if it charges. It is an old battery that will not hold a charge above 5.7 V and will be the first one I am going to test the desulphating process on.

I am using a 15v/3A Lab supply and was surpised to feel that it was getting quite hot after about 15 minutes (the large heatsink at the back was quite hot to the touch even if not hot enough to burn) although I have never actually kept it on for more than a few minutes at a time. The diodes were cold and the transistor barely perceptibly hotter than ambient temperature. The pot was feeling warmer to the touch. Is this normal? I set the voltage to 9V and then adjusted the pot until it was indicating 0.6 Amps and then left it there. I noticed that the voltage gradually increased ever so slightly.

Some other observations that may be useful to someone. I could only buy the magnetic wire by weight so had absolutely no idea how much wire to buy. Three lengths of 1mm/18# wire (77 to 78 * 3 = 234 meters) weighs 1.62 Kilograms (3.56 pounds). At least this can provide a guideline to someone who can only buy the wire by weight.

Another was that when I tied off the ends of the coils I left one side longer than the other for easy identification. I found that the trigger coil had to be connected to the opposite of the other two coils. Is this a rule of thumb?

I did not have a 10W 12 lamp so used two 5 Watt lamps in series.

[Groundloop]

I finished building the circuit on Tuesday and eventually had time to test it last night. Success!!! Here are some pictures of my progress to date.

I then tested it the charger on a 6V battery that just to see if it charges. It is an old battery that will not hold a charge above 5.7 V and will be the first one I am going to test the desulphating process on.

I am using a 15v/3A Lab supply and was surpised to feel that it was getting quite hot after about 15 minutes (the large heatsink at the back was quite hot to the touch even if not hot enough to burn) although I have never actually kept it on for more than a few minutes at a time. The diodes were cold and the transistor barely perceptibly hotter than ambient temperature. The pot was feeling warmer to the touch. Is this normal? I set the voltage to 9V and then adjusted the pot until it was indicating 0.6 Amps and then left it there. I noticed that the voltage gradually increased ever so slightly.

Some other observations that may be useful to someone. I could only buy the magnetic wire by weight so had absolutely no idea how much wire to buy. Three lengths of 1mm/18# wire (77 to 78 * 3 = 234 meters) weighs 1.62 Kilograms (3.56 pounds). At least this can provide a guideline to someone who can only buy the wire by weight.

Another was that when I tied off the ends of the coils I left one side longer than the other for easy identification. I found that the trigger coil had to be connected to the opposite of the other two coils. Is this a rule of thumb?

I did not have a 10W 12 lamp so used two 5 Watt lamps in series.

Mars67,

Glad you got the circuit running. :-)

The circuit does make "a lot of noise" on the plus input line. Use a large electrolytic capacitor
over the plus and minus of your lab power supply. This will probably reduce the heating in
the power supply. 1000uF 25 Volt or thereabout.

The pot-meter should not be very warm.
What is the wattage rating on your pot-meter?

0,6 Amp at 9 Volt input is OK. Lots of copper wire in an air-core, yes.
Trigger coil ends is opposite to the power coil ends, is correct.

The 12 Volt lamp is only used to test if there is a output for those that do not have a o-scope.
So two 12 Volt 5 Watt lamps in series or in parallel is OK for testing.

GL.