how to find flyback transformer pinout?

how to find flyback transformer pinout and i don't hav a datasheet
i don't hav anything

AndyGadget4 years ago
I've used the procedure HERE with success.
I have this problem too.

How do I find which pins are the inputs to the primary coil on the flyback?
This site ( says "With a simple ohmeter this is very simple, you will find easily the primary inputs because the coil resistance is about 1 ohm"

I bought a new flyback a couple of weeks ago. My flyback has 10 pins. I got these results:

Pins ..... Resistance
1 + 5 .... 2 ohms
1 + 9 .... 1.8 ohms
5 + 9 .... 0.9 ohms

2 + 8 .... 0.9 ohms

3 + 4 .... 0.8 ohms
3 + 6 .... 0.8 ohms
4 + 6 .... 0.6 ohms
All the other combinations (i.e; pins 1 + 3) produced no resistance, so that means that pins 1 + 3 are not connected. Conversely, this means that pins 1+5+9 are connected; pins 2+8 are connected; pins 3+4+6 are connected; and pin 7 and pin 10 are not connected to any other pins.

The first problem is that many of these gave me a resistance close to 1 ohm, so I still don't know which pins to use for the primary coil.
The second problem is that a flyback should have two sets of connected pins; pins that connect to the primary coil, and pins the connect to the secondary coil. However, I seem to have 3 sets of connected pins (or five sets, depending on how you count). Does this mean something is disconnected inside my flyback?

I didn't know what to do, so I just went ahead and connected it to the CFL circuit. I tried pins 5+9, 2+8, and 3+4 as the pins to the primary coil, along with every combination of the 4 pins on the CFL circuit, but did not get a single arc for any of them. Does this mean that my brand-new flyback is bad?
The problem is that there are many different designs of flyback transformer.  If you bought it new you should have a part number on it, on the packaging or in the place you bought it from - Do a search for that and you may be able to find a data sheet on it. 
Okay. The part number is 247718/244247. I'm looking it up now.
I tried that procedure and it didn't work
1.) Use an ohmmeter to identify windings on the core.

2.) Build a little audio oscillator, keep the output voltage low, and then apply the output to a pair of wires on the transformer.Use an oscilloscope to identify the outputs, in conjunction with part 1.
3.) The levels measured will help you judge turns ratios.


Get More Out of Instructables

Already have an Account?


PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!