Need help with flyback transformer project.

[Makke]

Hello, I got two flyback transformers, one small(BSH8-II5513L) from a blackwhite tv and one big(FTX-14005) from an old computer monitor.

The small flyback transformer has 10pins and the big one 11pins.
(See Attachments)

So what i want to do is make a HighVoltage PowerSupply out of each one just to learn (and possibly to have some fun). I want to start with the small one since its (if im correct) the weakest one.

I have though about following a 555-Timer diagram. But sadly i dont have any 555-timer.
Does anyone know if i can hijack one from something?

I live in Sweden and its kind of hard to find any store that sells timers and transistors near by.

Anyhow. I think i have found the inputs and outputs of both the flyback transformers, but i am not so sure about it since none the outputs give any arcs. Does flyback transformers give arcs even though they arn't hooked up to a timer?

If anyone is willing to help me with this project please add my MSN: Makke01@hotmail.com
Or post in this topic. Though MSN would be easier since i could use a WebCam.

Im sorry if my English isn't to good. Afterall English isn't my main language.

[cody]

Here is a link to show you how to find which pins to use.
How to find the primary and the secundary coils of a FlyBack transformer by Jean-Louis Naudin

If you are just starting out, i would recommend not using a 555. I think its easier to use a self oscillating circuit, but thats for you to decide. Unfortunatly I dont have a schematic of the simple one i built, maybe ill make a drawing for you. I recomend using a bu508d for the transistor, many others will work but i have had good success with that one.

Start by using the link above to find the HV lines. The hot line is pretty obvious but its harder to find the ground for it. Here is a link to give you some ideas on what circuit you can use.
High Voltage Power supply diagrams by Jean-Louis Naudin

If i have time tonight ill draw up the circuit i used, its easier than all those above and works great. Good luck

[Xenomorph]

You can use this one : POWERLABS' High Voltage Solid State Flyback Driver

Make also sure that you familiarize yourself with the correct procedure to handle High voltage devices.
A flyback transformer stores energy ! Touching the transformer without discharging it properly to ground even after the driver has been switched off can be dangerous.

[SuperCaviTationIstic]

if you have access to an oscilloscope and a musical keyboard synthesizer, probe the speaker leads with the scope and check if any of the settings make pure sine waves, or square waves. You then have an audio frequency modulator! My ancient battery powered tiny Casio keyboard has a potentiometer on the board that lets me fine tune the frequencies.
Some of the keys actually output a wave form that is a multiple of the sound you hear, so it's 2x or 3x the actual audio frequency!

Good Luck!

[Xenomorph]

if you have access to an oscilloscope and a musical keyboard synthesizer, probe the speaker leads with the scope and check if any of the settings make pure sine waves, or square waves. You then have an audio frequency modulator! My ancient battery powered tiny Casio keyboard has a potentiometer on the board that lets me fine tune the frequencies.
Some of the keys actually output a wave form that is a multiple of the sound you hear, so it's 2x or 3x the actual audio frequency!

Good Luck!

And what does this have (even remotely) to do with his intention to build a HV power supply with a flyback? Maybe i just donīt see it?

[SuperCaviTationIstic]

it can be used as a frequency oscillator. You can modulate a current with it, at the specific frequency. As opposed to a 555 timer. This will only help you if you can use the audio range or a double or triple the range.
Then replace the speaker with the flyback primary

[Makke]

Thank you cody and all the others. I have already followed the tutorial on how to find the primary and the secondary coils. If you look at the small transformers image you will see a blue line'd areas, the area to the right with two pins inside is the input, the blue lined area to the left is the 0v output thing.

nvisser, i have already played with the flybacks a bit, and havn't seen any sparks anywhere near 25,000v, same goes for my voltage reader.
and with breaking the flybacks, do you mean that *bzzzzzzr* sound comming from inside my flybacks? Maybe they are already broken? :S
This noise starts everytime im applying electricity to the input of the flybacks with my 10-15V 2.5A power supply.

[Xenomorph]

it can be used as a frequency oscillator. You can modulate a current with it, at the specific frequency. As opposed to a 555 timer. This will only help you if you can use the audio range or a double or triple the range.
Then replace the speaker with the flyback primary

Now i understand your point.
That would make his first build very complicated as opposed to that simple self oscillator and require him to buy a synthesizer.
He in addition would need to add an amplifier stage because he wants to build a POWER SUPPLY and not an (audio) signal generator.

This noise starts everytime im applying electricity to the input of the flybacks with my 10-15V 2.5A power supply.

That sounds as if you have "shorts" in the flyback. Did you load the flyback with something at all (spark gap etc.) ?
Observe the bottom pins. Is there arcs visible between some of those pins?
If so, then you would have to isolate the unused pins with PVC or any good isolation material.
I used cable material as you can see here:


Uploaded with ImageShack.us

For me, flybacks where two secondary cables are on top work better with
less shorting at the bottom pins, because the physical distance is bigger that way. Like this model here:



Uploaded with ImageShack.us

[Makke]

That sounds as if you have "shorts" in the flyback. Did you load the flyback with something at all (spark gap etc.) ?
Observe the bottom pins. Is there arcs visible between some of those pins?
If so, then you would have to isolate the unused pins with PVC or any good isolation material.

I placed the output of my flyback close to the 0v pin and then added electricity to my input of the flyback. The noise is still there even though im not holding the output of the flyback close to the 0v pin. And this is happeneing in both of my flybacks. I could always support you guys with a video of it?

And i must say this forum is pretty neat, the activity is large and the help im getting in so little time is very appreshiated.

[Makke]

I used cable material as you can see here:
*IMAGES*
For me, flybacks where two secondary cables are on top work better with
less shorting at the bottom pins, because the physical distance is bigger that way.

Smart thing with the cable housing. Ill do that
And I will make a arc sparker like that to.

Edit: Even though i placed cable housing on the not used pins the noise is still there, and the arc im getting betwin the output and the 0v pin is just tiny.. It even seams like spark im getting from the flyback is less than what im getting at the input..
*sigh* maybe my flyback is broken or something

Edit2: I just checked the difference betwin the input and the output with my DCV meter, i set the range to 200v and the input from my powersupply was around 9, on other hand. The output of my flyback was around -130.. As you can see the difference is alot!. But why am i not getting any arc?

[cody]

Makke,
Its strange you arent getting good results . It may be the transformer, but would you please describe your power supply you are using as this may be the issue. Just tapping the primary on a dc supply wont usually give good results, it needs a higher frequency of pulses to get anything useful out of it.

[Makke]

Makke,
Its strange you arent getting good results . It may be the transformer, but would you please describe your power supply you are using as this may be the issue. Just tapping the primary on a dc supply wont usually give good results, it needs a higher frequency of pulses to get anything useful out of it.

Im going to record a video of the whole process including my PSU. Ill be back with a link in 5minutes.

Edit: A problem might also be that theres a short safe, so if i short out my powersupply for to long it will disable the power, The time i can short out the powersupply seams to have drained through the years and is now very short. So my powersupply is pretty much toasted.

I cant upload a video, this computer is to slow to upload anything but pictures, so Information will have to do.
The powersupply is outputing 2,5A and 10-15V depending on how you adjust the button.
Thats all the information i can get from the chassi. Are you wondering anything else?

And oh, to get a higher frequenzy i would need a timer right?

[Xenomorph]

What do you mean with shorting out your power supply ???

You do need a strong battery or a lab PSU that gives enough amperage to create sparks. Otherwise if the current is too low, nothing will happen.

And cody is right you need a high frequency to a continous arc. You can build such a circuit real easy with 1 transistor and 2 resistors. No timer chip needed.

[Makke]

What do you mean with shorting out your power supply ???

You do need a strong battery or a lab PSU that gives enough amperage to create sparks. Otherwise if the current is too low, nothing will happen.

And cody is right you need a high frequency to a continous arc. You can build such a circuit real easy with 1 transistor and 2 resistors. No timer chip needed.

Oh i already have a MOSFET transistor and lots of resistors on etc the monitors board. Please, if anyone of you have MSN messanger it would make things alot easier.

What do you mean with a Lab Power supply Unit? The Power Supply i got is a red box with a wheele on it to adjust Voltage, it also has a red led that glows brighter the longer you connect + and -. And oh, did i forget to tell you that when i input electricity to my flyback the red led on my power supply glows.. Is the flyback supposed to do that? (Drain energy while the output isn't being used)

[Xenomorph]

Oh i already have a MOSFET transistor and lots of resistors on etc the monitors board. Please, if anyone of you have MSN messanger it would make things alot easier.

What do you mean with a Lab Power supply Unit? The Power Supply i got is a red box with a wheele on it to adjust Voltage, it also has a red led that glows brighter the longer you connect + and -. And oh, did i forget to tell you that when i input electricity to my flyback the red led on my power supply glows.. Is the flyback supposed to do that? (Drain energy while the output isn't being used)

Sure, the primary then acts like a resistor and dissipates energy, but that is nearly a short-circuit because the resistance is probably very low.
Thatīs why you use a switching circuit.

I want to kindly advise you again to make sure that you have familiarized yourself with safety issues of high voltage transformers to avoid injuries.