Battery vs. Power Supply

[greghaa]

From the reading I have done, the best way to run the SSG is with a battery as the primary, and at least the same size and type
of the battery being charged.

I have also read that using a power supply that is at least capable of 3 amps is an acceptable way of running the device.

Is there some insight into this that anyone could provide? Why is it better to use the battery?

What if I use a converted PC power supply that is capable of delivering up to 12 or 13 amps at 12V?
Would that be ok? I know that it will run the device, but will it work as well for charging?
If so, why or why not?

As always, thank you all for your valuable information.

--

[Ren]

Hi Greg,

This is an often debated topic. Yes a power supply can be used, but it will generally net inferior results. My understanding of this is such.

Firstly, with a high resistance coil (low amp draw) this isn't as pronounced but as your builds get bigger and more powerful one must consider more than the "average" current shown on your analogue meter. Think "instantaneous surge current" and you are on the right track. A good batteries ability to surge heavy currents is always going to be better than the power supply. This is one of the factors in producing the transient spike. I remember Bedini talking about his 10 pole monopole that runs on 24v, saying that the total impedance is so low that when it switches on the batteries/switches pretty much think it's a dead short circuit. If his switching time was too long here the currents that could flow would destroy the switches/coils. So even though the meter is pinned @ 10 amps at full steam the peak amperage would be MUCH higher.

Secondly there is an impedance relationship between the primary battery, coil/circuit and secondary battery. The power supply changes this as its impedance is different to that of the batteries. It is said that some of the energy in each pulse is actuay returned to the primary, this unique arrangement is altered when a power supply is used. There is also a strong possibility of permanent damage to the power supply, most electronic switching devices like SMPS don't like transients at all. The sensitive components have a number of filters and suppressors fitted to remove and protect them from this spike.

In the end a spinning wheel is better than no spinning wheel, we make the best of what we have access to.

Regards

[greghaa]

Thanks a lot for that info. I understand why now.

So in terms of batteries, is it always good to have the same size battery for primary and secondary (secondary is charging) or can I have a much larger primary
battery charging a smaller battery? I think I have read that the primary should never be smaller than the secondary, but would it matter if it were much larger?

[Ren]

Tune your machine, figure out it's average amp draw and use this to calculate the necessary battery for the front of the system sticking to c20 rates. Larger is fine on the front end, too large on the back and you may have trouble pushing it past 13v.

Regards

[Dan Heal]

I am able to charge a 7.2AH battery with a 5AH battery, although I do need to put a bit more charge in the primary at the end to get the charge to 14.5v but I haven't fully conditioned the charge battery yet. So it is possible to use a smaller primary, but as Ren said above don't have too much difference between the two.

[ZeusZcid]

Hi Greghaa,

In my experience a good way to charge batteries with HV spikes (transients) is to have a ratio of 1to4 or 1to3. As in 12v charges a 36v(1to3) bank or a 48v(1to4) bank of batteries. Here is my view on why, for instance if I use 12v 180ma to charge a 48v bank of batteries and my meter shows 80ma going through the 48v bank. Then all 4 of the 12v batteries see 80ms. 4x80ma = 320. so 180 in 320 out. Its not exactly like that as battery charging is a complicated and deep study but you can see where this can go.
I would suggest that if you do want to use a power supply like I prefer to, as it gives steady results then use a large capacitor bank between your power supply. Use quick caps so that you can get those fast peek amps but it isolates your PSU. From what I understand transients like caps better then batteries or PSUs mainly cos of impedance. I have found tho that it can be an issue in tuning the ssg or oscillators with a cap bank in front of the PSU. Just a question of what you prefer to do. For ease just use a large battery on the front.

Hope this helps.

[Tom C]

Hi Greghaa,

In my experience a good way to charge batteries with HV spikes (transients) is to have a ratio of 1to4 or 1to3. As in 12v charges a 36v(1to3) bank or a 48v(1to4) bank of batteries. Here is my view on why, for instance if I use 12v 180ma to charge a 48v bank of batteries and my meter shows 80ma going through the 48v bank. Then all 4 of the 12v batteries see 80ms. 4x80ma = 320. so 180 in 320 out. Its not exactly like that as battery charging is a complicated and deep study but you can see where this can go.
I would suggest that if you do want to use a power supply like I prefer to, as it gives steady results then use a large capacitor bank between your power supply. Use quick caps so that you can get those fast peek amps but it isolates your PSU. From what I understand transients like caps better then batteries or PSUs mainly cos of impedance. I have found tho that it can be an issue in tuning the ssg or oscillators with a cap bank in front of the PSU. Just a question of what you prefer to do. For ease just use a large battery on the front.

Hope this helps.

the batteries do not all get 80 milliamps x4 it is divided between the 4 batteries. if your battery is in series it is a 48 volt cell, looks like a single battery, all cells dividing the 80 milliamps. if they are in parallel the current is divided between the cells.


we are not even really concerned with the current, we are concerned with the potential, or the voltage, we want a hi spike not currrent flow, current destroys the dipole.

Tom C


Tom C

[greghaa]

Does the distance of the coil to the magnets affect the current in any way? I think I might have read that before but I am unsure.

I will shim my coil closer and see if it affects it. What other attributes affect current draw from the primary?

[ZeusZcid]

the batteries do not all get 80 milliamps x4 it is divided between the 4 batteries. if your battery is in series it is a 48 volt cell, looks like a single battery, all cells dividing the 80 milliamps. if they are in parallel the current is divided between the cells.


we are not even really concerned with the current, we are concerned with the potential, or the voltage, we want a hi spike not currrent flow, current destroys the dipole.

Tom C


Tom C

Hi Tom C,

May I ask then why is it when you have a 3v LED with a resistor across a 12v battery and it pulls 100ma(with a lot of energy dissipated across the resistor), then when you put 4x3v LED's across the 12v it also sees around 100ma same brightness. Do not all 4 LEDs see 100ma to be able to light up to the same brightness????. Why is it different for batteries? Is not the primary function of amps to push Ions from one plate to another with HV spikes doing the same thing just in a better way? I know that amp readings is not what we have to look at.

[Carlos Galvis]

Hi zeusZcid, i'm not sure on how to connect the charging batteries when in groups.... should it be a standard prarllell conection?

cheers
carlos

[ZeusZcid]

Hi zeusZcid, i'm not sure on how to connect the charging batteries when in groups.... should it be a standard prarllell conection?

cheers
carlos

Yep if your running the monopole as a beginner parallel is the way to go. May I ask what you mean by groups tho??

[Aram]

I have also read that using a power supply that is at least capable of 3 amps is an acceptable way of running the device.

Is there some insight into this that anyone could provide? Why is it better to use the battery?

I've always used power supplies, but I put a capacitor in parallel with the power supply to provide the current spike during the "on" phase, and prevent any reverse spikes from cooking my power supply.

I stopped using batteries because I found that charging was GREATLY affected when my primary battery started going low, even by a half volt. A power supply give me a consistent voltage level, and since I was rejuving batteries, I needed extended run times. Didn't want to worry about swapping out the primary, or recharging it. Power supply with a cap solved my issues.

Per your request below, I used a 15000 microfarads, 35 V cap. Plus others, but that's the size I've used most. Might be better with a larger one, but I haven't had any issues. And I have one a charger that I can adjust up to 3 Amp at 24 V draw with one of those caps, and I've never had any issues. Granted it has a very good quality power supply, a massive jobber designed for some sort of industrial lighting application.

[KarlSchmaltz]

I've always used power supplies, but I put a capacitor in parallel with the power supply to provide the current spike during the "on" phase, and prevent any reverse spikes from cooking my power supply.

I stopped using batteries because I found that charging was GREATLY affected when my primary battery started going low, even by a half volt. A power supply give me a consistent voltage level, and since I was rejuving batteries, I needed extended run times. Didn't want to worry about swapping out the primary, or recharging it. Power supply with a cap solved my issues.

What type/size of capacitor do you use? I would like to do what you do because I don't have enough batteries to run my motor for long periods of time. I don't know much about capacitors. My motor pulls about 2 amps, if that matters.

[ZeusZcid]

Hi Karl,

The higher the amp draw the more heavy duty caps you will need.
Here are some calculations.

1) Watts are equivalent to Joules per second. You have VxA=W in your case given you are probably running 12v then 12x2=24W. So 24w = 24J per second. So you will need a cap bank that can supply 24J per second.
2) Energy = ½*C*V², so if you have half a Farad you get ½*½*12² = 72J this should give you enough of a cap bank to handle anything the motor throws at it including spikes back and amp surges forward.
3) I tend to use high speed caps capable of 60V+ sometimes go to 200V. This protects my power supply very well. Also a diode on the positive coming into the bank makes me feel safe. Usually a power supply will have its own blocking diode. But I like to be redundant at times.

Hope this helps in any way. Don't trust my math tho as I am no math guru and always independently verify everything you get from forums.

Zeus

P.S you should probably also calculate the frequency of you motor as this will change the calculations and the size of you cap bank, it will probably not have to be as big as the calculations above suggest.

[KarlSchmaltz]

Thanks Zeus!

How do I calculate the frequency of my motor?