12V 60A car battery , maybe dead?

[Mars67]

The power supply delivers 12.06V DC. The two large resistors are 100 Ohm 5W connected in parrallel. I checked the value and get 49.5 Ohms. The pot is exactly 500 Ohms.

[Groundloop]

Hi Groundloop

Thanks yet again for your input. I am not sure about the connection of the pot as indicated on your circuit diagram. Again please excuse my ignorance. The pot has three connectors. The sweeper is in the middle. At the moment the 50 Ohm Resistor (2 x 100 Ohm 5W resistors connected in parallel) is connected in serial from the one connector on the side of the pot to the sweeper. The sweeper is then connected to L2. Should the two outside connectors i.e. the full 500 Ohms be in serial with the 50 Ohm with the sweeper going to L2? I will measure all the values and get back to you this evening.

Mars67,

The attached drawing may help you to verify that you have everything connected correct.

What is the type marking on your voltage regulator?

GL.

[Mars67]

Hi GL

Thanks for the schematic. I connected the pot correctly.
The Voltage Regulator is an ST L7809CV (L7809CV GK1AA v6 CHN308)
The Transistor is an BU208A made by ISC
The Cap is rated at 220nF 260V
I could not find the BYV29-500 so was given U1560 Diodes in stead (NFE16G U1560). I did manage to get BYV29-300s but did not try them in the circuit yet.

Your assistance and information is greatly appreciated.

[Groundloop]

Hi GL

Thanks for the schematic. I connected the pot correctly.
The Voltage Regulator is an ST L7809CV (L7809CV GK1AA v6 CHN308)
The Transistor is an BU208A made by ISC
The Cap is rated at 220nF 260V
I could not find the BYV29-500 so was given U1560 Diodes in stead (NFE16G U1560). I did manage to get BYV29-300s.

Your assistance and information is greatly appreciated.

Mars67,

I did download the data sheet for the L7809CV voltage regulator and it's a 1,5 Ampere rated type.
So the regulator will be warm at the current you are using in the circuit. It was right of you to put
the regulator onto a heat sink. The transistor and diodes you are using is alright for the circuit.

There is one test you can do to see if we get rid of the pot-meter heating:

Connect your 12 Volt test bulbs at the output and reverse the wires on the L1 coil.
See if the circuit runs with the L1 coil wires reversed. If the circuit runs and you get
light in the bulbs, try to notice if the circuit current usage went down with the L1
wires swapped. If the circuit does not run then just put the wires back as they where.

GL.

[Mars67]

Thanks GL

I will test it this evening when I get home. When I had the circuit built on the bread board it did not run with the L1 wires reversed but will test it anyway on the circuit as built.

Could the way the coils were wound have anything to do with it?