12V 60A car battery , maybe dead?

[Groundloop]

Just to add. I put the two 100 Ohm resistors in serial. With the pot fully open the circuit draws 150mAmps. It does not seem as if the other components are getting hot but the two resistors went up to 120 Degrees F and stays there.

I will check the circuit closely to see if there are any issues.

The charger does seem to work as the battery could only hold a charge of 1.2 Volts but can hold a charge of 10.5 Volts after about two weeks.

Mars67,

You can use resistors with higher wattage ratings. Wire wound resistors is OK to use in this circuit.
Keep charging on your sulfated battery until you get over 12 volt. Then discharge battery (with your bulbs)
down to approx. 12 Volt. Re-charge and repeat. Also check the water level in the battery and add distilled
water if low.

GL.

[Mars67]

Hi GL
The Capacitor I was using before was rated 220nF 250V. the one I am currently using is an Alcon KPF-9 0.22uF/2000VDC K/CD.

[Mars67]

Well I checked the circuit very critically and cannot find any glaring errors. What I decided to do was to build another circuit to see if I get a different result. This time I used TinyCAD to draw the circuit and then used a licensed version of VeeCAD to transfer the design onto veroboard and then built the circuit last night. I used the BYV29-300 Diodes that I also got and a 56 Ohm 5W resistor. the rest of the components are the same. I did not integrate the voltage regulator onto the same board and used my lab ps to power the circuit.

The great news is that the circuit worked the first time. I used two 6V 4A batteries that are quite old as a load and tested the circuit. I got the same result. D5 gets hot, R1 gets hot and the pot gets hot. I am really beginning to wonder what is going on here. I know some electronic engineers with very fancy oscilloscopes. I am going to ask them to help me do some measurements.

Any advice on what I need to measure where would be very welcome.

Here are some pics of the circuit. At least the actual circuit is much cleaner. Any comments would be appreciated.

Thank you

[Groundloop]

Well I checked the circuit very critically and cannot find any glaring errors. What I decided to do was to build another circuit to see if I get a different result. This time I used TinyCAD to draw the circuit and then used a licensed version of VeeCAD to transfer the design onto veroboard and then built the circuit last night. I used the BYV29-300 Diodes that I also got and a 56 Ohm 5W resistor. the rest of the components are the same. I did not integrate the voltage regulator onto the same board and used my lab ps to power the circuit.

The great news is that the circuit worked the first time. I used two 6V 4A batteries that are quite old as a load and tested the circuit. I got the same result. D5 gets hot, R1 gets hot and the pot gets hot. I am really beginning to wonder what is going on here. I know some electronic engineers with very fancy oscilloscopes. I am going to ask them to help me do some measurements.

Any advice on what I need to measure where would be very welcome.

Here are some pics of the circuit. At least the actual circuit is much cleaner. Any comments would be appreciated.

Thank you

Mars67,

You did a very clean and nice build.

If the components gets hot, but not smoking hot, and the circuits can be run for hours
without failing, then just use the circuit. Put it into a nice plastic box and use a fan
for cooling.

GL.

[Mars67]

Thanks Groundloop.
Two things have happened. The 5W pot on the original circuit was damaged (burnt?) at the position where the circuit draws 0.6 Amps. I am assuming this because trying to set it to a current draw of 0.6 it either jumps to 0.4 or 0.8. I have not yet tried a 0.47uF Capacitor but will try it on the original circuit this weekend.

The second is that I have managed to get a used analogue oscilloscope. So the learning curve has suddenly steepened somewhat for me.

It is a Pintek PS-605 60MHz dual trace oscilloscope. I am sure that it will be more than adequate for my purposes. It has a really cool function where you can test different components such as resistors, capacitors, diodes and transistors. I am busy studying the manual and have managed to take some measurements on the second circuit that I built last night. If my calculations are correct the circuit oscillates at 11.9 KHz. (the wave length is 4.2 divisions at a time/div setting of 0.2uS) It was interesting to see that the waveform on the "positive" side of L1 and one of the outputs of L3 looks very similar except that L3 is more "noisy". 

The peak to peak voltage on the positive of L1 (again assuming that my maths/understanding has not failed me) is 40V. (4 Divisions at a setting of volt/div setting of 1V and the probe at 10x gives me 40V)

The Voltage on L3 (L1 and L3 are connected the same way and L2 is reversed) Taken at the same side as L1 looks the same and the frequency appears to be exactly the same. The voltage there is also about 40V.

Does this seem correct?

Here are pics of the two waveforms I am talking about. The second one is L3.

Thanks
Marnus