How Do You Identify Primary and Secondary Coil Pins on a TV Flyback Transformer?

[wil3]

Hello. I have recently obtained a working television flyback power supply. I would like to run a pulsed signal through it to create a power supply for a small project I am working on. In order to do this, it is necessary for me to locate the location of the primary and secondary coil pins. I am aware that that large and intimidating wire out of the top is the secondary output, but I need help finding the other three pins. Here is how my transformer is labeled (it is still on its original circuit board):

1-GND
2-ABL
3-GND
4-210V
5-HEATER
6-BLANKING
7-23V
8-17V
9-130V
10-unlabeled
(pins run counterclockwise)

Which two of these are the primary coil connections, and which is the secondary ground? I can post pics if necessary.

Also, if anyone has advice regarding how to remove the transformer form the circuit board (desoldering it does not seem to be working) would be greatly appreciated.

Thank you.

 

[negitron]

This should help you:

http://www.electronicrepairguide.com/flyback-transformers.html

As far as desoldering, sometimes it's difficult get all the solder out of of plated through-holes with just an iron and manual desoldering pump. If this is all you have, however, it's not impossible. The best way is to first apply more solder to the joint you want to unsolder--that's right, I said more. Then heat the joint from below--hold the board up high with the solder side down and heat the joint to allow the solder to flow down onto the iron tip. Tap the excess off the tip and then put the board back down and re-heat the joint (allow a few seconds for the joint to fully heat) then apply your suction pump. Repeat, if need be. Do each pin like this and when they're all done, you can use needle-nose pliers to gently but firmly work each pin back and forth to break any remaining solder bonding it to the plated hole wall. After that, you should be able to work the part loose from the board.

 

[wil3]

Thank you for your description of the desoldering process. Regarding the flyback, I seem to be having some issues locating the correct pins, even with the article. It looks pretty clear that pins 2,5, and 6 can be eliminated, but I still need more information in order to narrow down the primary coil and secondary ground, especially given the two ground pins. Can you provide any more information?

Thank you.

 

[negitron]

As usual, Sam's Repair FAQ has a bunch of useful information. With some basic equipment you can identify the important pins on your flyback--since the labels on yours are nonstandard, you'll probably have to do that if you can't locate the manufacturer's pinout.

 

[berkeman]

Hello. I have recently obtained a working television flyback power supply. I would like to run a pulsed signal through it to create a power supply for a small project I am working on.

How are you going to drive the transformer in this other circuit? Still in a flyback configuration? What input voltage are you going to be using, and what rectified output voltage are you looking to make? What size output capacitor (and voltage rating) are you going to use?

 

[wil3]

I actually am going to be using the power supply from a CFL bulb to drive the transformer. I have a 11 watt CFL circuit that I will attach to the primary pins. I have to admit, I am making this for a jacob's ladder project ala this instruction set:

http://www.instructables.com/id/MAKE-A-HIGH-VOLTAGE-SUPPLY-IN-5-MINUTES/

Because of the parameters of the bulb circuit, this project should not create lethal currents. I have made a Tesla coil safely, and I just want to make an alternate power supply for smaller things like plasma globes. Thank you very much!

 

[dlgoff]

As far as desoldering, sometimes it's difficult get all the solder out of of plated through-holes with just an iron and manual desoldering pump. If this is all you have, however, it's not impossible. The best way is to first apply more solder to the joint you want to unsolder--that's right, I said more. Then heat the joint from below--hold the board up high with the solder side down and heat the joint to allow the solder to flow down onto the iron tip.

Instead of using a pump/suction-bulb, I've heated as you say then give the circuit boards' corner a quick swat on the bench top causing the solder to clear the hole and drop on the floor. I've never broken a board this way and have always been successful in clearing holes.

I have to admit, I am making this for a jacob's ladder project...

Yea. I made one years ago but I used a neon sign transformer (9kV, 18mA). Sounds harmless but can still kill you. Be careful if you must.