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Observations of JB's Solar Tesla charger
It has been quite a while since I posted here and I haven't done any work on the bench since my father passed away in January. I'm not sure when I will get back to doing some bench work so I wanted to relay some thoughts I had been working on.
First, I want to pass along some thoughts on JB's Solar Tesla charger videos. On the input side we see a DC power supply set around 17v with current fluctuating from zero to around 3 amps. I was pondering on what kind of circuit or circuit function could cause the fluctuations that we see on the input. What do we know about the circuit?
1 The DC power supply is taking the place of a solar panel for demonstration purposes.
2 The purpose of the circuit is to boost performance of charging a battery from a solar panel.
3 From the name, the Tesla switch or some derivation of it must be part of the circuit.
4 The output of the device is generating 10+ amp pulses to the charging battery that appear to be about 1/2 second apart. So we have an output that behaves exactly like the cap discharge circuit of the SG charging the battery. To show 10+ amp pulses on the amp meter, the voltage of the cap being discharged must have been quite high relative to the charging battery.
Under normal conditions, the voltage output of the panel must exceed the voltage of the battery for the battery to charge. So how do we keep the battery charging when the panel output voltage has dropped below the charging battery voltage? We need to boost the avaliable potential from the panel to a potential above that of the battery. How do we do that? The joule thief circuit and the SS SG will both accomplish this but they both draw constant current from the source. JB's charger shows fluctuating input current. So what other ways are there? One way would be to charge several caps in parallel from the panel and discharge them in series to get a potential higher than the charging battery. Sounds like what the Tesla switch or scalar charger does. That would also explain why the input current from the Power supply varies. The current would be the highest when the caps being charged were empty and would diminish as they charge up. Now this does not explicitly imply a single charging stage. A primary set of caps could be discharged into a secondary cap which in turn is discharged across the output battery. In this case, the charging and discharging of the primary caps into the secondary cap can be performed at a much higher frequency than the discharge of the secondary cap into the battery. Even in this two stage system, the input current would vary the same as before. It would diminish as the secondary cap gains voltage. It may be possible to draw some energy from the environment if the pulse from the primary caps to the secondary cap was kept short such as 100us or less.
This brings me to another thought on the behavior of caps to DC current. A cap will displace DC current until the potential on both sides of it equalizes. So by displacement it appears to pass AC current continuously and blocks continuous DC current. Can we use the partial DC current displacement to our advantage?
Experiment: hook up a battery with a cap and a light bulb in series. The bulb will be lit by displacement current until the potential equalizes. Now disconnect the cap and bulb from the battery and hook the bulb in parallel with the cap. The bulb lights as before until the cap is drained. So we now have just lit the bulb twice using the battery only once.
What if we apply this to the 4 battery Tesla switch. Think of it as a compound Tesla switch. Arrange the switches so the left bank of 2 batteries is in series for 24 volts and the right bank is in parallel for 12 volts. Now connect several caps in parallel to each other and place this cap bank in series between the right and left bank positives with the negatives of the battery banks connected together. The parallel battery bank is charged via displacement current thru the cap bank until it equalizes. Now disconnect the caps from the circuit, hook the caps up in series and discharge them across the parallel bank. We just charged the parallel battery bank twice but only discharged the series battery bank once. It stands to reason this should be a net gain in charging even after the switching and cap losses.
Food for thought,
Alex
It has been quite a while since I posted here and I haven't done any work on the bench since my father passed away in January. I'm not sure when I will get back to doing some bench work so I wanted to relay some thoughts I had been working on.
First, I want to pass along some thoughts on JB's Solar Tesla charger videos. On the input side we see a DC power supply set around 17v with current fluctuating from zero to around 3 amps. I was pondering on what kind of circuit or circuit function could cause the fluctuations that we see on the input. What do we know about the circuit?
1 The DC power supply is taking the place of a solar panel for demonstration purposes.
2 The purpose of the circuit is to boost performance of charging a battery from a solar panel.
3 From the name, the Tesla switch or some derivation of it must be part of the circuit.
4 The output of the device is generating 10+ amp pulses to the charging battery that appear to be about 1/2 second apart. So we have an output that behaves exactly like the cap discharge circuit of the SG charging the battery. To show 10+ amp pulses on the amp meter, the voltage of the cap being discharged must have been quite high relative to the charging battery.
Under normal conditions, the voltage output of the panel must exceed the voltage of the battery for the battery to charge. So how do we keep the battery charging when the panel output voltage has dropped below the charging battery voltage? We need to boost the avaliable potential from the panel to a potential above that of the battery. How do we do that? The joule thief circuit and the SS SG will both accomplish this but they both draw constant current from the source. JB's charger shows fluctuating input current. So what other ways are there? One way would be to charge several caps in parallel from the panel and discharge them in series to get a potential higher than the charging battery. Sounds like what the Tesla switch or scalar charger does. That would also explain why the input current from the Power supply varies. The current would be the highest when the caps being charged were empty and would diminish as they charge up. Now this does not explicitly imply a single charging stage. A primary set of caps could be discharged into a secondary cap which in turn is discharged across the output battery. In this case, the charging and discharging of the primary caps into the secondary cap can be performed at a much higher frequency than the discharge of the secondary cap into the battery. Even in this two stage system, the input current would vary the same as before. It would diminish as the secondary cap gains voltage. It may be possible to draw some energy from the environment if the pulse from the primary caps to the secondary cap was kept short such as 100us or less.
This brings me to another thought on the behavior of caps to DC current. A cap will displace DC current until the potential on both sides of it equalizes. So by displacement it appears to pass AC current continuously and blocks continuous DC current. Can we use the partial DC current displacement to our advantage?
Experiment: hook up a battery with a cap and a light bulb in series. The bulb will be lit by displacement current until the potential equalizes. Now disconnect the cap and bulb from the battery and hook the bulb in parallel with the cap. The bulb lights as before until the cap is drained. So we now have just lit the bulb twice using the battery only once.
What if we apply this to the 4 battery Tesla switch. Think of it as a compound Tesla switch. Arrange the switches so the left bank of 2 batteries is in series for 24 volts and the right bank is in parallel for 12 volts. Now connect several caps in parallel to each other and place this cap bank in series between the right and left bank positives with the negatives of the battery banks connected together. The parallel battery bank is charged via displacement current thru the cap bank until it equalizes. Now disconnect the caps from the circuit, hook the caps up in series and discharge them across the parallel bank. We just charged the parallel battery bank twice but only discharged the series battery bank once. It stands to reason this should be a net gain in charging even after the switching and cap losses.
Food for thought,
Alex
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