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**dragon** · 07-02-2010, 07:19 PM

I havent worked with that particular circuit but I've found sometimes you need to have a pull down resistor on the base of the PNP to fully bring it to zero volts. It can sometimes have an effect on the NPN as well by not allowing the voltage it needs to fully turn it on ( using the pull down resistor ). You might need to play with various resistances to get a good balance between the NPN on state and PNP off.

I remember having a heck of a time with a similar arrangement although I did get it working, just not as well as I would have liked.
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**TanTric** · 07-02-2010, 07:34 PM

...

so you suggest i maintain the 100ohm resistance allready in the circuit, but try another ones from that resistor, to the base of the PNP?

i even tryed other combinations and kinds of transistors like TIP3055/TIP2955...

but will not work neither!

**Joit** · 07-02-2010, 11:43 PM

rectifying Pulses.
It does not work really well, that you can calculate it that way, as you would do for normal AC with load on it.
Pulses have only Side of strong Potential, when you rectify them, even in this Transformer, i doubt you will ever get the double Voltage from the Ac, what is created at your Coils, its almost the same AC what your meter shows or 50% more as that.
The missing Push into the negative Side makes the different.

Different Transistors. Much Transistors have different Gate resistance,
so, the Signal what they get at the gate is driving the Amount, what they open at C-E. They open first slowly, till they reach a Point, where they complete open, that are the characteristik Curves at the Datashets.
You may place Resistor there, what match, or place a pot there to better adjustment.

Neons have small Coils inside, what fire the Gas, Bulbs has a big Wire inside.
Both have different Resistance, and it can slow down the Output from your Secondary very much, when it is to low Resistance.

I did take once a Converter apart, and they dont have really any Coils in it anymore, they work more with Transistors, so not sure, if this Example really works.

Even the Input at this Schematic, when you change it, it will change the whole Frequency at the 555 Timer, and you need to readjust it.
But to start anywhere, i would try to switch the Primary Wire once, to see if you get a different,
then R3 for 50Ohm and put another Potential there, to control the gatevoltage better,
even, may another Pot for the 2nd Transistor, that you can control them seperate.
R1 can be a Potentiometer too, that you can change the whole Frequency better.

**dragon** · 07-02-2010, 11:58 PM

Originally posted by TanTric View Post

so you suggest i maintain the 100ohm resistance allready in the circuit, but try another ones from that resistor, to the base of the PNP?

i even tryed other combinations and kinds of transistors like TIP3055/TIP2955...

but will not work neither!

From the base of the PNP (Q2) to ground. You might use a 50k variable resistor to see where it works the best then measure the value when it's running good. Replace the adjustable with a fixed resistor when tuned.

I'm just going on what I ran into when trying to work with the NPN/PNP shuttle. I had a problem where the PNP would stay partly on all the time and wouldn't run the transformer properly.

The pull down resistor works well for the PNP but it steals a little from the NPN on state which doesn't allow it to turn fully on. I'm not sure of the "happy middle". Anyway that will get it working but it's not a perfect fix...
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**citfta** · 07-03-2010, 12:09 AM

wrong transformer

Hi TanTric,

If you are trying to use a transformer that is for mains use (either 60 or 50 hz) it will not work well on a frequency any higher than about 100 hz. I haven't calculated the frequency range you can get with that 555 timer circuit but I am pretty sure it is higher than 50 to 60 hz. You will have to wind your own transformer or get one designed for higher frequencies. The laminated steel core of a mains transformer causes the transformer to have a very high input impedence at high frequencies.

citfta

**sucahyo** · 07-03-2010, 01:18 AM

Tranformer may not work best at high frequency. But I found it produce bright enough CFL at 2KHz.

I think the transistor switching is the cause of poor performance. Maybe a better transistor or transistor in tandem will improve performance.

**TanTric** · 07-03-2010, 05:14 AM

report

is getting better guys, just some more doubts...

@cifta, i think i can get from 0mhz to ...khz range with the timer! is this incorrect?

i have tunned the frequency generator, now i have a oscillator that can go from mhz to khz range, the C2 cap (0.1uF value) let me get very low frequencys, by replacing it for (=/>0.01uf value) alow me more higher frequencys.

R1 is now a 47k potentiometer
R2 is now a 10K potentiometer
and R4 is now a 1Meg potentiometer

potentiometer on the R3 to transistor base, dont seem to change to much the performance!

the push pull is still not working, i tryed all that you kindly suggested, putted a 10k potentiometer from both transistors base's to negative, still nothing, with separated 10k potentiometers on each base of the transistors, nothing! the push pull dont wont to work, is that the magic to get better performance, or will not improve so much?

now at 9V/1A input , output with 25W incandescent onload is 65VAC

with 12V/1.3A input, output onload is 85V!

much more better that the 45V i was getting before, twice the brightness now, but still not my goal.

i tryed a diode to rectify to dc, same brightness, but only 65VDC onload, i measured the current output and is 40mili amps!

so that make me assume that in AC mode im getting 80mili amps at 85VAC = 6.8W output... with an input of 12VDCx1.3Amps = 15.6W!

close to 50% efficiency... but i think i can get better?

that make me wonder, because in my "kapagen solved" video, i putted my 25W bulb lighting very much bright that with this setup BUT with only 4.95W (91 DC x 0.045A) from the mais grid, i shouldnt get at least the same brightness with 6.8Watt?

now i can adjust the frequency so my DMM can read the voltage without load, it can reach 300V with 12V input.

what can i improve more in the circuit?

dragon, joit, cifta and sucahyo, thank you very much!

**Joit** · 07-03-2010, 07:28 AM

Another Limitation from this Transfomer is the secondary, i measured mine,
and it has about 0,4mm / 26 Awg Wires, where you can expect after this Table a maximum Power Transfer from 360mA.
When you would force to run more Power through, then the Wires do heat up.

The Keyword DC to Ac in Google end mostly up with buy a Transformer,
here is some lecture, how to do it the classical Way.
YouTube - Lecture - 22 Basics of DC to AC Converter 1
I did doing it the other Way around, i made a Coil with thick Wires
and wrapped into the middle couple turns of thin wires and pulsed it with a Timer Circuit.
But the limit is again at the thin wire, that it heats up, when it gets to much current,
but else it seems it is a bigger Problem, even when it is so easy to rectify it.
What else i did do was, to put a Diode to catch the Spikes at the Collector and connected it to the secondary, but then my whole Circuit plus Timer is under HV, and was not the first Transistor and Timer chip i did destroy in this Way.
And i dont think, this Transformers are build very well, they maybe work well for 220V/50Hz, but i think noone do really count the losses there.
And mainly it is used for create HV for a Magnetron, but lesser for transmitting Power.
I did found once a Ducument from a German what did convert Dc with couple resistors and few breakers, but its anywhere at the deep space of my Hdd,
May there is still another Way to make a Converter again with 4 Capacitors, maybe.
But they are allways Frequency depending also, a crude guess is Hz equals Farad, so when you work with 1khz, you may use 0,1 or 0,01�f Caps.

**TanTric** · 07-03-2010, 02:53 PM

joit

thank you my friend, thank you very much!

dont understanded the fisrt part of your post, because im only pretending to pass just 50miliAmps of current...

im just finishing the probes of my "pc-osciloscope"... so i can know the frequencys involved here! and if i am really sending the 50Hz needed... my lab is getting better

if not i think i can make my own transformer, what do your advice?

ferrite core/ air core?

i have 2 different coils, one of 120ohm, and another of 220ohm but half the thickness (more thin), i also have a ferrite core coil with 0.9ohm resistance and close to 1mm wire! can i use the primary inside the secondary? or it must be outside?

the 50hz transformator that i am trying (purpose of this thread) haves 112ohm on secondary, and 1.1ohm on primary...

i also have a coil (seems like a pancake) with 15K resistance secondary, and 3.3ohm primary, maybe i can put it to act as a flyback transformer to output a lot of KV?

hugs

peace

**Joit** · 07-03-2010, 04:24 PM

First Part of my Post.
When you did power your Circuit with 12V1Ah, then i think you use more then 50mA, 50 ma are 0,05Ah, i only hope, you dont have a mesurment Error there, because you cant do much with 50 mA.
And Powering a thick primary Coil with 1 Ah, then the Power will be transfered into the secondary over the magnetic field, and then there can be this limitations.

Anyway, when you think about, to make your own transformer as i wrote, then it should not make much matter, if it is inside or outside.
I did make it first inside for the powercoil, primary, and the secondary was outside.
http://www.energeticforum.com/attach...pulsedcoil.jpg
At this Picture it is the right tall one and the little Coil beside i did put inside.
The big one had not much wires, maybe one layer with 40 Turns and a Aircore, (vitamins tubule)
the small one had maybe 150 turns with 0,3mm wire with an ferritcore.
the Ends are made from Milkbottle caps, with a screw through and glued with hotglue, the ferritcore is there in the middle.
Somewhere someone mentioned, that Ironcores actually dont amplify magnetism,
but repells it away, a iron or ferrit core does increase most time the efficience, but not sure,
in which cases a only a Aircore is better, it maybe depends on the use of the Coil.
At this setup, it is better, do dont use a core for the outer Coil because it will slow the Pulse down, what i have seen, but for the inner coil a core works better.
Ferrit or Iron, Ferrit reacts faster then Iron, thats why i use mainly ferrit too.

Another thing for the place is, when you power a Coil, then the stronger Part from the Coil will be on front side of the Coils and inside also, so anyhow hard to say, wich place is better,
i still play sometimes around with it, because i can see some things on it,
what i still have not figured out now complete.
A Video what i made about it, it maybe shows better, how it is made. Sorry for the bad Quality but better then nothing.

The power coil is also with mixed wires, started with some thicker wire, i think 0,3mm and the other half was 0,2mm,
wound only to one side with close turns,
and the next layer back are only 45� or lesser wound,
that the magnetic Field do concentrate at one Side.
When i made Coils where the Layers are left right left right, it disturbs the pulsed Field to much.
And at all, it did not give me a real Sinus wave at the Output.

**Joit** · 07-03-2010, 04:31 PM

i also have a coil (seems like a pancake) with 15K resistance secondary, and 3.3ohm primary, maybe i can put it to act as a flyback transformer to output a lot of KV?

I had a similar Coil once too, i think it was from a Roof-Light system,
this Transformers are usual made for 220 to 24 V,
and as i did pulse the thick Coil , it gave not bad Voltage out, like here.
I had to turn off the Sound because of the Noise, but it was about 3Kv.

**TanTric** · 07-03-2010, 05:55 PM

uau

@joit, very impressive work! big toroid you have there! cool stuff!

okey, now that you kindly educated myself about my doubts i think its time to experiment again!

i will report soon!

hugs

**dragon** · 07-03-2010, 08:22 PM

JuJu, I'm not exactly sure what your trying to accomplish with the circuit but if your trying to light a bulb with less energy I posted a series LCR cirucit some time back that will lower the energy needed to power them. I built the circuit originally to lower the power needed to drive a wire wound heater but it works with any resistive load.

You use the primary of the MOT, a motor run cap and the load (resistance) is what you want to run. With the numbers shown it works best with a 1200 to 1500 watt load ( 10 to 12 ohms resistance ). It will drive the heaters at full heat using about 500-600 watts of input. I showed it running 1000 watts of light a bit ago using 600 watts. It was a mismatch of resistance, one 500 watt halogen and 5 100 watt bulbs.

It won't run motors as it alters the frequency in the circuit. It's not overunity but it is an extreemly efficient way to drive resistive loads.
________

**everwiser** · 07-03-2010, 11:07 PM

Originally posted by dragon View Post

JuJu, I'm not exactly sure what your trying to accomplish with the circuit but if your trying to light a bulb with less energy I posted a series LCR cirucit some time back that will lower the energy needed to power them. I built the circuit originally to lower the power needed to drive a wire wound heater but it works with any resistive load.

You use the primary of the MOT, a motor run cap and the load (resistance) is what you want to run. With the numbers shown it works best with a 1200 to 1500 watt load ( 10 to 12 ohms resistance ). It will drive the heaters at full heat using about 500-600 watts of input. I showed it running 1000 watts of light a bit ago using 600 watts. It was a mismatch of resistance, one 500 watt halogen and 5 100 watt bulbs.

It won't run motors as it alters the frequency in the circuit. It's not overunity but it is an extreemly efficient way to drive resistive loads.

How are you sizing the L & C? Are you sizing them for resonance @ 60Hz or are you shooting for a particular value of L (+) or C (-) reactance?

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