Use for the Tesla Switch

[garrypm]

Hi all,

There seems to be some really good replications going on. Keep up the good work.

I am looking for some advice -

If I want to probe around the circuit with my scope, where is the best place to
connect the gound lead for the scope ?

My setup seems very touchy - if I probe across + and - of battery 3 for example,
the system seems to lock into some strange pattern, I get more hum from the
transformer and my present output of 4v (rectified and across 5000uf) jumps to
around 8.5v. The small 5 watt 12v bulb glows somewhat brighter.


Thanks, Garry

[Matthew Jones]

Be careful with the IC and the Scope. Unhook you IC from PC before you go probing see if that helps.

Normally if I look at anything it will be between the collector and emitter (Or what ever you have) of the switch's or across the windings. Not much else to look at.

Matt

[Matthew Jones]

Hi David

Hi David
Yes indeed you were.
I also got this morning my #10 AWG wire and when I looked at it I was just like what the hell !the wire is too strong to warped only wire how about three wire so i think i did mistake by ordering 10AWG wire I should order 14 AWG which i couldn’t find in the place where I make my order and here in Sweden nothing you can find the wire ,the transformer ,the 1 farad capacitor ,basic stamp so i order all these parts from USA and I pay for shipment and taxes in USA and I also pay taxes here when I receive the order for example I pay today for only the 120" wire 67$ can you imagine and i pay 128$ for shipping the transformer and i pay here 75$ so only the transformer cost me 270$and the wire 200$ i just mention these number because i remember you said before big one will cost 600$ i wish it will cost me that number i thing bill will be over 1100$ and i am satisfied with that if i can do it right.

Thanks David
Ehsan.

That #10 might not be easy to work but you should try to use it. You will have better results with 3 strands of 10 than you will with 6 strands of 14.

You just make a wood block to fill the core of the spool. Then use pliers covered with plastic or something soft to bend the corners.

Nothing easy about the big ones but they give you a good show when its done.

Just make sure you do not break that insulation and you won't have any problems.

Matt

[ehsanco1062]

That #10 might not be easy to work but you should try to use it. You will have better results with 3 strands of 10 than you will with 6 strands of 14.

You just make a wood block to fill the core of the spool. Then use pliers covered with plastic or something soft to bend the corners.

Nothing easy about the big ones but they give you a good show when its done.

Just make sure you do not break that insulation and you won't have any problems.

Matt

Hi Matt

Thanks again for the advice i will do that when i will wind the transformer.
but I have another question, when I unwind the 3000w transformer I found that it was winded with #10AWG wire but aluminum enameled magnet wire not cooper wire will that wire work because i noticed that the aluminum wire little easy to warp than the cooper wire i ordered and beside i can make use of that wire or maybe use it in another transformer.
One more question, while winding if the wire cut, can I solder it and continue winding or remove that wire and wind new wire?
What is the disadvantage of soldering the wire?

Thanks
Ehsan

[Matthew Jones]

Hi Matt

Thanks again for the advice i will do that when i will wind the transformer.
but I have another question, when I unwind the 3000w transformer I found that it was winded with #10AWG wire but aluminum enameled magnet wire not cooper wire will that wire work because i noticed that the aluminum wire little easy to warp than the cooper wire i ordered and beside i can make use of that wire or maybe use it in another transformer.
One more question, while winding if the wire cut, can I solder it and continue winding or remove that wire and wind new wire?
What is the disadvantage of soldering the wire?

Thanks
Ehsan

I have no advice on aluminum wire. I know they make it but I have never had experience with it.
As far as soldering goes, I do not see any problems from the, I have done it several time myself. But get heat shrink to go around the wire and make sure you cover the whole thing up past the joint. You do not want arcing.

Matt

[nvisser]

Scope

It is good to disconnect the earth wire on your scope’s supply line as you will
pick up terrible loops between your scope earth and serial cable earth and you
can blow some components. So this way your scope’s earth is floating and
isolated and you can probe anywhere in the circuit.
I find the best way to look at pulses are over the windings. You also cannot
use 2 scope channels to look at the 2 windings as their earths are not the same.
If you want to do that you have to use the top common + terminals as your
earth and than probe on the coils.

[ehsanco1062]

I have no advice on aluminum wire. I know they make it but I have never had experience with it.
As far as soldering goes, I do not see any problems from the, I have done it several time myself. But get heat shrink to go around the wire and make sure you cover the whole thing up past the joint. You do not want arcing.

Matt

Thank you Matt you give information that make a lot of things easy.
You’re always making our problems easy and you gave us the solutions.

Thanks
Ehsan

[garrypm]

Need more help - please

Hi all,

Has anyone else built the darlington pair circuit from Matt?

I took a leaf out of Dave's book and bought the 2 line LCD for my arduino
and put a program in to easily adjust the timing real time.

I figured the safest place to put the scope was across the output of the
transformer.

Pretty sad results at this stage - but we will persist.

Can someone with more nouse figure out from the scope shot, whether my pair of MJE13007's are switching fully or not.

Sorry, I should have added, my transformer has been rewound with 0.8mm wire (I think thats 20gauge). the 2 primaries 5 metres each and
the secondary 6.25 meters.
Thanks, Garry

[citfta]

Hi Garry,

If your scope input it set for DC and the center line of the scope is 0 volts then it appears you only have one side of the circuit working. You can also put the scope connections across the transistor on each side to see if they are both switching. Make sure none of the rest of the circuit it grounded and then put the scope ground on the negative side of the transistor ( the emitter ) and the signal lead on the positive side ( the collector ). With the transistor off you should see voltage on the scope. When the transistor turns on the voltage should go very close to zero. Because of the way this circuit is wired you will also see the voltage drop when the other side switches on. You may need to slow the pulsing speed way down to be able to tell the difference. Do not lower the pulsing rate by making the pulses longer for this test as a long slow pulse could blow the transistor because of the high current in a long slow pulse. In other words just add some long pauses between pulses to slow down the pulse rate instead of making the pulses longer. Good luck.

Carroll

[ehsanco1062]

Hi Matt
I have this reading for running tesla switch on different PULSOUT and the DC voltage across the load
Load 10w 12v

BS2
PULSOUT VLoadDC
250 8,51
500 9.21
700 9.43
800 9.48
1000 9.58
1200 9.64
1400 9.68
1600 9.70
1800 9.71
2000 9.73
2200 9.74
2400 9.75
2600 9.76
2800 9.76
3000 9.77
3200 9.77
3400 9.78
3600 9.78
3800 9.79
4000 9.79
4200 9.79
4400 9.79
4600 9.79
4800 9.794
5000 9.80
5200 9.80
5400 9.80
5600 9.80
5800 9.80
6000 9.80
6200 9.80
6400 9.80
6600 9.80
6800 9.80
7000 9.80
7200 9.80
7400 9.79
7600 9.79
7800 9.79
8000 9.79
8200 9.79
8400 9.79
8600 9.79
8800 9.78
9000 9.78
9200 9.78
9400 9.78
9600 9.775
9800 9.77
1000 9.77

Here can notice that the max. Voltage 9.80v was when the PULSOUT 5000 but I can never reach the value dnewkirk has in his test maybe because he use 6w load and my batteries not charged
The batteries voltage before doing the test was:
B1 =12.30
B2 =12.54
B3 =12.29
B3 = 12.59
When I used 3w load I get max VloadDC 11.96v when the Batt voltage was 12.40
What I am worried about is the charging rate is not as I hoped, when I did the first run the Batteries readings were:
B1=12.80
B2=12.78
B3=12.83
B4=12.82
And after running 16 hours with 10w load and swapped Three times the Batteries readings are:
B1=12.33
B2=12.37
B3=12.25
B4=12.39
I am using transformer bigger than the transformer dnewkirk from RadioShack RS 273-15128
And
Primary 1 is 60 feet
Primary 2 is 60 feet
Secondary is 75 feet but I litz the wire and I am using four new Batteries 12v 7.2Ah Lead Acid Batteries



THanks
Ehsan

[ren]

Need more help - please

Hi all,

Has anyone else built the darlington pair circuit from Matt?

I took a leaf out of Dave's book and bought the 2 line LCD for my arduino
and put a program in to easily adjust the timing real time.

I figured the safest place to put the scope was across the output of the
transformer.

Pretty sad results at this stage - but we will persist.

Can someone with more nouse figure out from the scope shot, whether my pair of MJE13007's are switching fully or not.

Sorry, I should have added, my transformer has been rewound with 0.8mm wire (I think thats 20gauge). the 2 primaries 5 metres each and
the secondary 6.25 meters.
Thanks, Garry

Hi Gary,

Citfta suggestion of an off time is a good one. I am running Arduino as well, Im interested in the adjustment of the timing on the fly option you have installed. Could you share the code and hardware you opted to use?

@ All.

Looks like its time to get a new meter. I originally measured my MOT primaries @ just over 4 ohms. I have wound some coils for my SG with the same gauge, and they are massive, @ only 2.2 ohms. So I checked with another meter and it reads 1.3 ohms on the primaries and 1.7 ohms on the secondary (which is slightly longer obviously). Now that sounds pretty spot on to me, considering the size of the spark I get when I manually switch it Im more inclined to think my second meter is more correct.

Anyone got a MOT laying around and can measure the resistance of the primary

One more HonG coming today and I should be able to start this thing up.

Regards

[Matthew Jones]

Hi Matt
What I am worried about is the charging rate is not as I hoped, when I did the first run the Batteries readings were:
B1=12.80
B2=12.78
B3=12.83
B4=12.82
And after running 16 hours with 10w load and swapped Three times the Batteries readings are:
B1=12.33
B2=12.37
B3=12.25
B4=12.39
THanks
Ehsan

I think you are doing pretty good there buddy. Just remember the maximum, although a good to thing to look for, is not all of the tuning. After you find that voltage then you adjust according to the drop on the battery. You have to find that sweet spot between the 2.

Once you do, make sure to do a baseline test and look to see what you are getting from it.

Good Job
Matt

[garrypm]

Hi Ren,

No problem.

The LCD I purchased from JAYCAR at $29.00. It's the freetronics job that plugs straight onto the Arduino Eleven.

The code, well I cheated. I took the bits out of BLINK and pluged them into the code from the
Freetronics website for the LCD -

Freetronics - 16x2 LCD Shield Quickstart Guide

Simply declare 2 new integers PW and PWI for pulse width and PW increment.

If this is too messy I'll edit it later - but here are the parts I did - look for the lines withs asterisks on the end ****************

--------------------------------------------------------------------------------------*/
byte buttonJustPressed = false; //this will be true after a ReadButtons() call if triggered
byte buttonJustReleased = false; //this will be true after a ReadButtons() call if triggered
byte buttonWas = BUTTON_NONE; //used by ReadButtons() for detection of button events
int PW = 2500 ; //
int PWI = 1 ; //
/*--------------------------------------------------------------------------------------
Init the LCD library with the LCD pins to be used
--------------------------------------------------------------------------------------*/
LiquidCrystal lcd( 8, 9, 4, 5, 6, 7 ); //Pins for the freetronics 16x2 LCD shield. LCD: ( RS, E, LCD-D4, LCD-D5, LCD-D6, LCD-D7 )
/*--------------------------------------------------------------------------------------
setup()
Called by the Arduino framework once, before the main loop begins
--------------------------------------------------------------------------------------*/
void setup()
{
//button adc input
pinMode(10, OUTPUT); ***************
pinMode(11, OUTPUT); ***************
pinMode( BUTTON_ADC_PIN, INPUT ); //ensure A0 is an input
digitalWrite( BUTTON_ADC_PIN, LOW ); //ensure pullup is off on A0
//lcd backlight control
digitalWrite( LCD_BACKLIGHT_PIN, LOW ); //backlight control pin D3 is high (on)
pinMode( LCD_BACKLIGHT_PIN, OUTPUT ); //D3 is an output
//set up the LCD number of columns and rows:
lcd.begin( 16, 2 );
//Print some initial text to the LCD.
lcd.setCursor( 0, 0 ); //top left
// 1234567890123456
lcd.print( "Freetronics 16x2" );
//
lcd.setCursor( 0, 1 ); //bottom left
// 1234567890123456
lcd.print( "Btn:" );
}
/*--------------------------------------------------------------------------------------
loop()
Arduino main loop
--------------------------------------------------------------------------------------*/
void loop()
{
byte button;
byte timestamp;

digitalWrite(10,HIGH); **************
digitalWrite(11, LOW);
delayMicroseconds(PW); // wait for a second
// digitalWrite(13, LOW); // set the LED off
digitalWrite(10, LOW);
digitalWrite(11, HIGH);
delayMicroseconds(PW); ****************

//get the latest button pressed, also the buttonJustPressed, buttonJustReleased flags
button = ReadButtons();
//blank the demo text line if a new button is pressed or released, ready for a new label to be written
if( buttonJustPressed || buttonJustReleased )
{
// ; lcd.setCursor( 4, 1 );
// ; lcd.print( " " );
}
//show text label for the button pressed
switch( button )
{
case BUTTON_NONE:
{
break;
}
case BUTTON_RIGHT:
{
lcd.setCursor( 4, 1 );
lcd.print( "RIGHT" );
break;
}
case BUTTON_UP:
{
lcd.setCursor( 4, 1 );
PW = PW + PWI ; *****************
lcd.print( PW , DEC ); ****************
break;
}
case BUTTON_DOWN:
{
lcd.setCursor( 4, 1 );
PW = PW - PWI ; *******************
lcd.print( PW , DEC ); *****************
break;


Need more help, just ask.

The only down side is when you actually press the button, the freq. changes - I guess it takes longer
doing the code it has to, but once you release, it settles back pretty quick.

For my own work, I tried the scope probe across the minus of batt 3 and plus of batt 4 - like you guys said -collector + and emiiter -. Still can't understand the waveform.

Anyway, more playing and learning.

Thanks, Garry

[citfta]

Hi Garry,

Try this then with your scope. Connect it across one of the top batteries. Just connect the signal lead to the positive and the ground to the negative. You should see a sawtooth looking signal. With every other tooth pointing down. What you should see is the battery coming up in voltage when that side is being charged and then the battery voltage going down when that side it being discharged. That is what causes the up and down sawtooth waveform. You will need to turn the scope sensitivity up most of the way as the signal is only a few tenths of a volt unless you really have a heavy load on it. Then you can also look at the other top battery and you should see the same thing. If you don't see this then post a scope shot of what you do get and I'll take a look at it and try to help.

Can you also post a scope shot of what you did see when you connected across the transistor?

Carroll

[jpolakow]

re-winding transformer

Hi team,
I've been following this thread and have decided to embark on replicating. I'm starting with the small switch. So I've taken apart the transformer and starting to re-wind. I have a couple of quick questions- Is it neccesary to clean the varnish off all the laminations before re-assembling? I read if there are any air gaps between the laminations it can cause flux leakage.Also is it neccesary to re-dip the transformer in varnish? Are you guys meticulously winding each turn so all turns lay next to each other and the layers are uniform or are you just winding kind of hapahazardly and fitting as many turns as you can on the bobbin (according to the ratios specified)?

Sorry if these questions seem elementary, I've never wound a transformer before. However I a a quick learner and do my research. Have a good day!
John