Disassemble an E-block Transformer





Introduction: Disassemble an E-block Transformer

I planned on making a guitar pickup, but lacked the enameled wire. Intent on trying to make it without buying anything, I thought for a while and came up with the idea of taking it out of a transformer for my old antenna rotator.

Unfortunately, the gauge of the wire inside the transformer was too large to use for a guitar pickup, but it still is good enough for an electromagnet or whatnot.

Step 1: Tools.

1 E-block transformer

1 pair of needlenose pliers

1 can of industrial strength repetitive task preparedness

Step 2: Assess the Situation

The transformer I held in my hands was made of small strips of steel all put together in a laminated and interlocked fashion. Your results may vary.

I immediately noticed that the entire thing was encased in a resin-like shell to protect it and hold the darn thing together.

Step 3: Begin

Start by taking one side and declaring that it is the top. You will work down from there.

On the top, take your trusty pair of needlenose pliers and insert them into one of the corner screw holes and pry one corner up.

Putting the whole it and kaboodle in a vice will hold the project steady.

From your loosened corner, crack the resin shell and laminating material between the layers of steel by lifting up and sliding along the crack on the sides.

The first layer is the hardest to remove, mostly due to the layer of resin that holds it to the wire coils and other layers.

Step 4: Remove Keeper

After the first E part is removed, take your pliers and pry off the flat sided field keeper on the other side.

Step 5: Do It Again

Pry off the next E-piece and keeper.

Then do it again.

And again...

and again...

and again...

and again...

Step 6: Done

After the last block is removed, you get two coils of wire in a plastic holster. Yay.

Now, unwind the tape, cut off the solder and other odds and ends, and wind onto your next project.



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    18 Discussions



    1 reply

    laminated steel sheets prevents eddy currents which will drop your efficiency drastically. also steel of transformer is high silicon special steel which doesn't retain magnetism

    Thanks. I scavenged a big transformer from a construction dumpster. Obvious damage so it's not safe to plug in. Just want to take it apart for the iron core so I can rewind it with larger guage wire.

    thank you soo much! i have a transformer that weighs like 30 pounds out of a light post soo,,, yeah lol ^_^

    i love you, i have desassembly my e-block in 5 minute thanks you.
    sorry for my english i'm french beginer ^^

    I use the smaller bit to tap out the first e shaped keeper, after breaking the resin bond.

    have you tried winding them for special voltages?
    i have and it works
    i only used one of the 2 formers and made an autotransformer to change 16vac to 12,9,7,5,3,2, by the tappes of  3,5,12       3-5 =2v   5-12=7v.etc
    a standard 48x28.5mm winding is 9.47turns per volt.(10-13va/w)
    20t-v 5va mini transformer.
    240v is about 2200 turns(approx) of 0.125mm wire.(10-13va)

    1 reply

    sounds like the worlds greatest fire hazard lol be careful to much could cause a fire

    I have one that had no hole in the corners, and seems to literally be glued and soldered together....I had really only wanted to find the portion of the wire that had shorted, but this thing made me "hammer mad" and that didn't help get it apart either :-)
    2 replies

    Your Idea is the reverse of my problem. Maybe you can help me. I have 8-9 identical chargers / transformers that charge my cordless tools. My meter shows that the transformers are dead. But, attached to each are identical circuit boards (1/2" X 1 1/2"). But nowhere does it state the transformers' output.. I wanted to buy 1 or 2 and solder the circuit boards and then run direct to my tools or try as chargers.
    The output on the block staes 21V-500ma to charge an 18 volt battery or possibly run the tool directly.
    I have seen; 12 and 16  volt transformers, about the same physical size, but is there any way to use the existing components to determine what transformer they are working with?
    Thanks in advance, all replies accepted.

    Do you know the input values (ie 120 vAC, or 220 vAC, etc)? 

    Other then hooking them up to the proper input voltage, and measuring the output, and then attaching a load to the output, I don't know of a another way, offhand.

    I haven't done this in years, nice to see again. How easily did the wire unwind, or haven't you yet?


    5 replies

    Some of the old one I used to take apart weren't. Do you use the things as spools then?


    Some transformers I've worked on are DIPPED in lacquer after winding. If it gets soaked in there good.... then the wires are as hard to unwind, as the plates are to separate. It's usually easy to tell that kind cause they lack the tape, to hold together the coil. On a side note, that kind of transformer is MUCH less likely to develop the dreaded BUZZzz. Check your wire CAREFULLY, before re-using it. usually, there's nothing wrong at all, but sometimes the enamel coating can crack. not too bad, if you're making a pick-up coil, but not healthy if you're using it for a tesla coil.