Gray Tube Replication

[crunner40]

Hi Pranav,

Thanks for the update on the LV switch. I was surprised to see that you place it after the diode - your latest post makes more sense.

Re my motor: I designed it back in 2007, but didnt have time to build it until this year. It is expensive and very time consuming to make.

The shell, end covers, rotor and bearing housings are all aluminium.

The shaft is 316L stainless steel - 1 1/4"

Bearings are NTN heavy duty.

Magnet core material is laminated from insulated iron wafers.

Insulators are machined from HPTFE or similar.

MANY hours of work, and over US$5000 so far for the material, and the labour costs of the few jobs that I have had to outsource.

Inertial torque (torque developed by rotating mass without the additional torque developed by the magnet pulses) is around 4.5 HP. I am hoping for a substantially higher torque once it is running.

Are you using a combination of electromagnets, and permanent magnets on your motor?

[pranav2010]

odd even number

i think gray sir use odd number combination

gray sir used 3 on rotor 9 on stator ,coil number of turns is 108,they used 3

cset, 5kv supply,in first motor 18 (1+8)cap were used

Edwin Vincent gray (1925-1989) (1+9+8+9)

in 1971 gray formed limited company

isn't this strange

[pranav2010]

about switch

hi crunner

i made mistake in diagram

put switch like this

lv---switch---diode------->gap<------------hv

one more think i want to tell you try small wire in winding it will take small current

one more think i want to ask you

what material you use for shaft,body,magnet core,bearing cover in your motor ???

what is shaft size???


thank you

have great day

[nat1971a]

i am not sure what my voltage levels are on the HV side as my volt meter wont read that high..i only measure the cap connected to the load now to see what is going on....

if it doesnt fire try shortening the gap b/w your HV anode and LV anode until it does....i find it is quite finicky....i guess thats why tesla was using gaps with spring loaded handles on it as the gap may not readily jump all the time

[crunner40]

Hi Nat,

thanks for the suggestion. I will give it a try, and report back to you.

Do you have any feedback regarding my post above to Ghst, and Aaron re voltage levels?

[crunner40]

Hi Ghst,

thanks for the reply and the drawing. I will try this as soon as I can pick up a new meter, and some new components for a voltage splitter.

It occurs to me that my (old) voltage splitter may have had a faulty component all along, and I may have been getting erroneous HV measurements. if so.. maybe my HV level is not high enough to make the circuit work.

What is the minimum voltage that the HV must achieve to jump the gap, get the slamming effect, and cause the radient event? Has anybody determined this?

I watched some excellent videos last night - including one from Aaron, and one from AE vector. They show clearly that the circuit works - and my tube should function. In the case of AE though, the voltages were MUCH higher - 1000 LV & 10,000 HV. I dont believe that Aaron stated his voltages, but he was feeding the circuit with an auto ignition coil, so I have to assume 5KV plus on the high side..?

What voltages are you using?

[Ghst]

Crunner40
You should try to get the tube to fire first. Please try this modification to your circuit, to get the basic function of your tube. http://img198.imageshack.us/img198/3696/trythisq.jpg The high voltage must jump to the grid in order to charge the cap. You will have to play with the LV electrode to get the gap right.

edit: I made a mistake, the wire from the series coils should connect between the diode and the tube.

[nat1971a]

hi crunner40,

not sure if i will be much help as i am not qualified in this field.

but try disconecting the negative b/w your bridge rectifier and your 2nd power supply...does it work then?

Edit - but retain the part from bridge to your earth ground

[crunner40]

Hi Pranav,

Thank you for your post, and for the diagram. Your drawing appears to be of the 3 point system.. the only differences that I can see between your drawing and my schematic are the following -

1) You have the LV switched between the diode and the tube, and not between the LV supply and the diode.

2) You have a bypass diode fitted in parallel to the capacitor on the HV side.

Can you tell me whether this circuit is working for you? If it is, then maybe I need to shift my position of my LV switch.. And maybe the bypass diode has some other effect?

I always thought that the LV switch should be on the supply side of the diode, not the tube side. If it is on the tube side it will of course ARC, and that would result in lost energy..?

Regarding my coils. The wire is AWG15.5, and there are 108 turns on each coil. This was calculated based on the information obtained from the "stripped motors". And for the dimensions of my coils - closely matches Grays motor as reported by Alan Francour.

On test firing the coils, I have found that the wire is too large. It takes 8uF to fire them and obtain a strong repulsion. Now that I have the initial test results i am presently winding another pair with smaller wire. The goal is to reduce the size of the Caps - this will reduce the power consumption.. the trick is to match the impedance of the coils to the capacitors.

In the Gray configuration the pulse is applied to 3 coils on the rotor, which are connected in parallel; the rotor is then connected in series to the 3 stator coils which are also connected in parallel. The parallel-series-parallel impedance must be low enough to allow the "lightning strike", but high enough to produce the desired amount of repulsion.

I look forward to hearing back from you.

[crunner40]

Lazy tube is proving to be very stubborn..

Hi Aaron,

Thank you so much for your assistance.

I was hoping that when I wrote to you today I would have good news.. and a working tube.

Unfortunately, that is not the case.

I have attached a diagram of the way I connected the capacitor into the circuit - following your suggestions. The capacitor is 220V 250uF, and I am half-wave rectifying the independant supply with a microwave diode (I am waiting for more 6A100's to arrive).

The output to the anode of diode 28 at the LV electrode is 320V DC.

I have removed diode 46, and taken the coils directly to ground. The coils are now in series. Batteries #1 and #2 have been removed as per your instruction.

Even with no load on the grid, I cannot get the tube to spark between the HV and LV rods - across the gap - if there is a diode on the LV side.

With the LV rod backed out, and the LV switched to the diode 28, the voltage on the LV rod is 320V DC. The potential on the HV rod is 2800V DC.

As I screw the LV rod in - closer to the HV rod, the LV rod remains at 320 V DC, until at a consistent spark gap distance the voltage on the LV rod, and the cathode of the diode, jumps to approximately 2800V DC... but there is no spark across the gap. The diode clearly blocks the HV, but there is no momentary conduction before it slams shut, and therefore no arc-over.

Alternatively; if I back out the LV rod, and connect it directly to ground, then turn it in, at a similar spark gap distance to that mentioned above the gap arcs and the HV capacitor discharges. If I leave the LV rod in this position, and recharge the HV cap, then the cap will discharge again immediately the gap reaches arc-over voltage.

I checked the discharge of the LV capacitor, and it is fine. I have tried the circuit with caps charged and power supplies turned off, and also with power supplies running. There is no difference. Both caps hold their charge, and do not self discharge when the power is removed.

Unfortunately the voltage divider on my multi-meter failed today, and I have blown up my meter. Now waiting for new resistors, and a new meter before I can take accurate Hv measurements again.

The circuit I tried today was your "Silent Plasma - 3 point".

I will try the "Silent Plasma - 2 point" next.. I am assuming the diode on the HV side should be maybe 4 parallel strings of 10 6A100 diodes? Or more?

I took a lot of time over the machining of the tube, to ensure accurate gaps between all of the components.. it is disappointing and puzzling that it wont fire when other, much more agricultural setups, are apparently functioning perfectly..

Any other suggestions that you, or other members have would be gratefully received at this point. It really would be nice to get past this point and start "playing" with the assembled motor.

[pranav2010]

two point system

this the two diagram of two point system and three point system

by the aaron sir

[pranav2010]

three point system

hi crunner

this is for you

[pranav2010]

About The Circuit

nobody send me any solution of my above diagram

please help me sir


hi crunner

i want to ask you, how many turns you apply and what is wire size of your magnet


i want to tell aaron sir's two point system is very steady and it will give very good torque

just read the thread you find it or else you can find it on youtube also


thank you

[nat1971a]

YouTube - Update 36 - Edwin Gray added pancake coil, choke, resistors, quenched spark gap to LV side


Update 36 - Edwin Gray added pancake coil, choke resistors, quenched spark gap to LV side of circuit

[Aaron]

@crunner40

Hi Crunner,

I looked at your diagram.

This is what I would try first.

1. Remove the 15kv diode at the bottom right of your schematic. Just have
the grid pickup going straight to and only the coils. If you have anything
else connected to the grid, it should be an overshoot gap, which you will
probably not need at the moment.
2. Wire the coils in series and flip one so they will repel. The way you
have them wired now, they are essentially short circuited and you will
greatly restrict the ability for the magnetic fields to collapse quickly.
3. Take the coils straight to ground and bypass battery #2 for now.

Having a battery behind the diode at the LV rod is very difficult to get to
work. I have only been able to get the effect that way only a few times.

It would be almost guaranteed to work if you replaced batt #1 with a
capacitor and have a separate power supply charging it to a few hundred
volts at a couple hundred uf's rating. I know this isn't as elegant as the
battery method, but at least you can get the system running and move
towards optimization later.

I hope this helps.