I want to wind my own transformer. What are some good techniques or references for such a task? I want to experiment with power transfer and winding ratios.
The amount of power depends on the size and quality of the core.
If you want to wind a transformer, first you must know the number of turns per Volt for the core you intend to use.
If this is not known, you can determine this by winding a test coil. Slowly increase the AC-voltage on the test coil, until a fast rise in current is observed. Just below this point is the maximum voltage for this coil.
With the number of turns per Volt known, you can calculate the number of turns for the voltages you need. Use 10% more secondary turns to compensate for the losses.
With the total number of turns known, you can calculate the largest wire size that fits on the core you intend to use.
For winding small transformers, with many turns of very thin wire, I can recommend a transformer winding machine. Big transformers are easier to make without a transformer winding machine. What you need is a device to rotate the coil former. This device must have a brake to stop the process, for instance to insert an insulating layer.
The winding equipment must also support the coil former to prevent it from bending under the pressure of the windings. Otherwise the core does not fit anymore.
An electronic (or mechanical) turn counter is nice to have.
Wind each turn next to the previous one and apply a layer of insulating paper after each layer of turns. Mechanical forces cause the windings to vibrate at the mains frequency if not properly fixed. Use glue, epoxi or high temperature tape to prevent this.
A really good post for someone who REALLY wants to make his own transformer. I found it also very interesting indeed.
I would say to him that there are many more interesting areas of electronics than this, but each to his own!! I once made a transformer for an Oscilloscope that I built, once was enough!!
I find that the huge offering of new & second-hand transformers in different sizes at a price I could not achieve as being very attractive…..plus the fact that Toroidal transformers are to my mind impossible for the private person to make and are far more efficient than a standard transformer, take up less room, make less noise, make less heat, give out less electromagnetic waves and the sine wave is cleaner…..why would I even buy a normal transformer let alone make one?
A really good post for someone who REALLY wants to make his own transformer. I found it also very interesting indeed.
I would say to him that there are many more interesting areas of electronics than this, but each to his own!! I once made a transformer for an Oscilloscope that I built, once was enough!!
I find that the huge offering of new & second-hand transformers in different sizes at a price I could not achieve as being very attractive…..plus the fact that Toroidal transformers are to my mind impossible for the private person to make and are far more efficient than a standard transformer, take up less room, make less noise, make less heat, give out less electromagnetic waves and the sine wave is cleaner…..why would I even buy a normal transformer let alone make one?
Toroidal transformers with not too many turns could be made by hand. If you need a 115 Volt to low Voltage transformer, You could rewind the secondary of an existing transformer and use the existing primary winding.
To wind a toroidal transformer by hand, you need a simple tool that fits trough the hole of the toroid. See drawing. First wind the wire on the tool. Then wind the transformer using this tool.
