Longwire EMF power Transfer System preliminary tests

[TomW]

Got a pile of HV parts from Wolvenar and have done some more fooling around with what I am calling the Long wire EMF power Transfer system LWEPTS for short.

This is all preliminary stuff yet. I am going slowly and one stage at a time as I get a feel for how it works from source to battery.

First stage is simply a 555 timer circuit with an approximate 50% duty cycle set up with a pot so I can vary the output frequency from around 250 HZ up to several KHZ. This drives an IGBT switch that drives the primary of my home made bifilar wound 1:1 transformer wound on a microwave transformer core which is wound with about 100 feet of #12 magnet wire. The secondary of the transformer is fed to a bridge rectifier built from individual high voltage [1 KV+] microwave rectifiers. I will call this the pulser stage.

Second stage is the simplest. It is a partial roll of RG58A/U coax. Don't laugh it was available is light wire and has substantial length in a compact package. Not exactly sure but it seems to be about half of a 500 foot roll so my guestimate of it's length is 200 feet. I will call this the transfer stage.

Third stage is the High Voltage unidirectional EMF pulse collection capacitors. This consists of 9 microwave high voltage capacitors arranged in a parallel configuration with a total capacitance of around 2 microfarads. At this stage I have one 15,000 microfarad 100 volt electrolytic that is also in parallel with these high voltage caps. The finished circuit will more than likely have isolation between the HV caps and the electrolytic. I will call this the High Voltage collection stage.

I think it would be a good idea to isolate the HV caps from the electrolytics and dump them as they attain a specific voltage level. Currently I just let all the caps charge up in parallel then dump to the battery with a manual momentary contact switch. Ideally the cap isolation and dump operations would be done automatically based on cap voltage level. I just have not settled on a method at this point.

There is no doubt in my mind that this system works. A 12 volt 300 milliamp DC wall wart drives the test circuit and I can regularly dump over 20 volts into the 12 volt battery.

With just the HV caps in circuit I can attain 50+ volts on them in less than a second. Filling up that 15,000 microfarad cap takes a bit longer tho so far up to 30 seconds to get around 20 volts.

SO far just low current source testing but maybe tomorrow I can test with a battery driving it which should up the transfer rate if for no other reaaon than a stronger pulse into the transformer.

Any suggestions for switching circuits based on voltage using simple components [no pics or processors please] would be appreciated.

At this point I must mention that I feel this system may have potential for a small hydro setup or wind mill but is unlikely to be very useful for high power levels but time will tell.

Cheers.

TomW

[drdongle]

With the high voltage peek that some have been reporting with these 1:1 transformers I would be concerned with it exceeding the dielectric capacity of the coax which is probably only 300 volts. If the insulation breaks down you could have a sudden failure in your system. I will be following your experiments with interest.

Dr.D

[TomW]

Dr. D;

I am fully aware of the voltage rating of the coax being exceeded. There are many nit picky points I am fully aware of but am not concerned with at this testing stage of the process.

Even Romex only has a 600 volt rating and most common wire is well below 1000 volt rating.

One question:

What have you used in your tests? I can only assume you are an academic from your usual answers which often point out the obvious from theoretical vantage points.

Without a massive university research budget here in the real world I use what I can find, usually for free. If and when dielectric failure occurs I will make a run of electric fence wire out a half mile and back and since it is dead cheap and uninsulated it will have a zero voltage rating on the insulation and an earth ground. Nothing is fused, either beyond the breaker in the box and there are exposed bare wires.

Thanks for your concern.

Cheers.

TomW

[RobC]

My feeling about this kind of system is that you would never run it without a load to absorb the voltage. True the voltage can go very high but with the right load at the receiving end the voltage should stay well with in limits.RobC

[drdongle]

Insulation breakdown is something that most people ( even those in the business) seldom consider, I thought it prudent to mention it, though you may infact never have a problem with as the Pulse charging system may not actually stress the insulation enough for it to be a factor.

 At this time I am only an observer of the "pulse chargers" that several here have built. Some time in the near future I will kluge one together. Currently I'm working to get my first wind turbine finished and erected.

Never underestimate the value of that free stuff ( I have great heaps of it much to my wife's annoyance).

Electric fence wire with proper insulators would certainly do the trick and keep the cows or goats in check in the bargain.

Keep up the experimenting.

Dr.D

[charged]

If you can scrounge lots of free coax, just run two parallel leads of coax with 6" pvc separators (tubing chunk with two holes drilled through sideways, 6" apart).

That will put you up into the multi-kv range of voltage tolerance between the two conductors.

Then you can use the center and shield leads of each cable as a single conductor.

The higher the floating voltage range of the receiving cap, the more power you'll be able to transfer. Then draw if off that cap with controlled switching through a bucking inverter circuit. (see the DC-DC diary page)

[TomW]

Folks;

After fooling around with this method awhile I have come to the conclusion that it indeed works. Problem being it only seems to be useful for moving small amounts of power.

It seems to be good at moving power from low power sources fine but will not move any significant amount of power.

I was getting about the same transfer rate from a very low current source as I was from a higher current source. The low current source being a half amp 12 volt wall wart and higher current source being 1500 amphours of 12 volt batteries.

Bottom line, as I see it now, is that if you have a low power source at some remote location that you can probably move a good portion of that power over a fair distance and trickle charge batteries.  Something like a small hydro setup far away from your point of use.

Perhaps it is my components or my methods but I think this system would be pretty useless for moving real power. Maybe someone with more personal energy and resources can carry it further along. For now I will have top view it as an interesting phenomena that may be useful for some applications but is mostly unrealistic as a method of moving real power over distance.

Other applications for AE / RE may exist such as getting charge level voltage from low voltage sources but that will be up to others to discover.

Cheers.

TomW