20-04-2012, 12:17 PM
Hi,
Thanks Mark; it took a while to put this thread together because I had a strange dream in that the weather improved giving outside temperatures above freezing allowing me to work on jobs outside then I awoke!!
Many thanks for your kind comments David and for taking the trouble to add the excellent video and information regarding putting together a very cheap digital counter using a Poundland calculator. I fully agree with you about the horrendous cost of covered wire suitable for wave winding and this is preventing me from experimenting with my fully restored expensive AVO Progressive Wave Winder. I actually bought a 10KG bobbin of Litz wire; it was in a brand new sealed box but when I got it home and inspected it the wire was more like rope as it was much too thick for our use; I still retain the wire.
I too did some experimenting a few years ago before buying a proper coil winder. One thing I did buy was a digital counter costing around £7 counting to 9999. Like your method with the calculator using a magnet and reed switch as a trigger I too used a magnet and reed switch to trigger the counter. It worked perfectly with only one drawback; the counter did not recognize forward or reverse so every time the switch triggered it notched up another turn. Owning a lathe is a huge benefit when it comes to constructing machines at home as shafts and bushes are no longer a problem.
Digital counter.
You are most welcome Lawrence and thanks for your reply.
I enjoy experimenting in the garage and am always on the look out for new ideas to inspire me. One day whilst browsing eBay I noticed a guy in America selling a set of 3 x DVD's these covering how to install 3 phase at home on a shoestring; at the time the DVD set cost around £17 so being inquisitive I bought the DVD's. What a delight these turned out to be giving something like six hours interesting viewing on TV; much better than the usual rubbish now shown.
http://unique3phase.com/
I've mentioned these before but as this thread is about transformers it is worth repeating to keep all the information in one place.
Douglas Arndt is the inventor of "Unique 3 Phase" in America and Doug is a great guy to know; he is most helpful and full of enthusiasm and only too happy to help out with any problems that might arise. Rotary and static phase converters are covered in great detail as is making a large home welder. The information I was interested in though was using a transformer.
My initial attempt involved stripping a big electric motor to obtain the bare stator to use for the transformer laminations and this can be seen on the bench in the back ground of one of the pictures. I had some success with this ending up with 3 phase but by this time my enthusiasm knew no bounds and I was on a high. I visited our local scrap yard and obtained an old scrap 3 phase welding transformer which took two of us to lift into the car with a lot of effort; boy it was heavy.
Scrap transformer as bought.
Back home I struggled but eventually had the transformer on the bench in the garage and set about stripping it. I wasn't too gentle with the windings cutting straight through them with a sharpened power saw blade and hammer. I went gentler as the formers were approached and ended up with the laminations still retaining the three heavy plastic formers.
Stripping the old windings the easy way.
For the primary winding I used 1.5mm conduit wire and for the secondary's used 2.5mm conduit wire the wire bought from Screwfix in 100M coils. I viewed the relevant section of DVD over and over until I was sure I knew what I needed to do. I followed the DVD instructions to the letter having taken careful notes. By this time I had gained some useful experience winding radio chokes and transformers and even designed and wound two transformers to my own specification so at least I had good basic knowledge of how the transformer worked. What was new though was this being my first 3 phase transformer and the winding wire would take a lot of breaking.
The aim was to obtain 1.5V per turn and experimentation is called for as no data is available for these scrap transformers. I was amused by Doug's method of winding; only the two outer sections of the transformer are used and Doug had his son running a couple of blocks with the loose wire end as he added each turn. I was awake the whole of one night thinking about this as I was working totally on my own and it was snowing outside and not much better in the garage. I finally fell asleep with a solution that I thought would work. The following day I selected a strip of plywood about 4' long and notched the ends. The strip now to be called a "Shuttle" was given a good sanding to remove all sharp edges as it would be handled a lot. The shuttle would hold 100M of 2.5mm conduit wire and what a tremendous help this proved to be. By threading the shuttle containing the wire through the window of the laminations I found I could pass the shuttle through about 8 times then place the shuttle down whilst the turns were neatly arranged and pulled tight by hand.
Shuttle in action during winding.
I wound what I considered to be extra turns for the primary using the 1.5mm wire then I wound on a short length of 2.5mm wire making two turns and leaving both ends stripped of insulation as I would be taking voltage readings. This was something else new to me because I didn't know a transformer could be powered up with only the primary winding installed. The first reading was something like 3.6V but as two turns were wound on this gave 1.8V per turn which I thought to be brilliant but this was short lived. I had bought a clamp type ammeter and at this voltage the current at idle was too high; I disconnected from the supply and kept removing turns until I obtained a reading bang on 3V giving 1.5V per turn with a nice low idle of 0.8A.
Without giving too much away I then wound on the secondary windings using the 2.5mm wire and this was like working with stiff rope compared to winding a radio transformer. I didn’t need to experiment with the secondary winding as I could accurately work out the turns required from the 1.5V per turn primary reading.
I did have a few worrying moments at power up whilst experimenting with the primary winding as I had tapped into the mains 240V supply in the garage giving me a supply of 30A protected by a 30A MCB which tripped a number of times taking out the central heating boiler right in the middle of winter. I well remember it being a tense moment the first time I powered up as I didn’t know what to expect and given the sheer size of this transformer would the mains consumer unit destroy itself?
Winding completed.
I used Doug’s instructions and could connect and adjust the secondary voltages to give perfect readings of 415V on two legs as shown in the picture; this brought a huge smile to my face with a great sigh of relief. The third leg was wound at 600V which for a mechanical engineer is pushing it a bit; 600V with a push of 30A from the supply isn’t something I take lightly and I treated it with the utmost respect ensuring by checking and double checking the supply was disconnected each time I touched the transformer; I didn’t even trust it whilst taking the 3V readings.
Perfect 415V.
I’ve added these notes on 3 phase 415V just for interest and to show just how easy transformer winding can be to even the basic novice such as me. Using Doug’s method a transformer can be wound to give virtually any output at any voltage. I installed 3 phase 415V into my garage for just under £120 and still use it most times I go into the garage. I can power up a single machine or a number of machines up to an estimated 10HP on my system. Once the machines are phase balanced to the transformer it is just like having regular 3 phase installed and all the machines run on full power unlike using a phase converter.
Ready for installing into garage and fully installed and working.
I hope the above notes demonstrate just how easy and simple it is to either step up or down the 240V supply. I found playing around with the 3 phase to be quite addictive and very much enjoyed the learning curve ending up with extremely cheap 3 phase 415V in my garage that will power machinery up to around an estimated 10HP on full power.
I have previously owned a Transwave 7.5HP phase converter and right from the start never liked it as I had to keep setting the adjustments for each machine I had coupled up to it. My home made 3 phase dust extractor used to take ages to come up to speed and the big Colchester lathe I owned at the time didn’t half rattle the converter if I put on a heavy cut. The converter doesn’t put out full power either.
It’s worth mentioning that playing around with this kind of power is highly dangerous for a novice and a single mistake could easily prove fatal. High voltage capacitors are used for phase balancing and a bank of these needs treating with great respect as they can remain live and fully charged even though power is turned off. I made up a pair of well insulated prods with a high power 1K resistor in series and used these to discharge the caps every time before handling them and I even followed up with a voltage check each time using my DMM.
Whilst covering the subject of powering big machines at home I eventually over the years learnt how to wire 3 phase 415V modern six wire motors enabling them to run connected in “Delta” from the 240V supply using two capacitors and if I can find my notes I'll add the details; I also hope to add details on the practical side of transformer winding at home in the near future.
Kind regards, Col.
Thanks Mark; it took a while to put this thread together because I had a strange dream in that the weather improved giving outside temperatures above freezing allowing me to work on jobs outside then I awoke!!
Many thanks for your kind comments David and for taking the trouble to add the excellent video and information regarding putting together a very cheap digital counter using a Poundland calculator. I fully agree with you about the horrendous cost of covered wire suitable for wave winding and this is preventing me from experimenting with my fully restored expensive AVO Progressive Wave Winder. I actually bought a 10KG bobbin of Litz wire; it was in a brand new sealed box but when I got it home and inspected it the wire was more like rope as it was much too thick for our use; I still retain the wire.
I too did some experimenting a few years ago before buying a proper coil winder. One thing I did buy was a digital counter costing around £7 counting to 9999. Like your method with the calculator using a magnet and reed switch as a trigger I too used a magnet and reed switch to trigger the counter. It worked perfectly with only one drawback; the counter did not recognize forward or reverse so every time the switch triggered it notched up another turn. Owning a lathe is a huge benefit when it comes to constructing machines at home as shafts and bushes are no longer a problem.
Digital counter.
You are most welcome Lawrence and thanks for your reply.
I enjoy experimenting in the garage and am always on the look out for new ideas to inspire me. One day whilst browsing eBay I noticed a guy in America selling a set of 3 x DVD's these covering how to install 3 phase at home on a shoestring; at the time the DVD set cost around £17 so being inquisitive I bought the DVD's. What a delight these turned out to be giving something like six hours interesting viewing on TV; much better than the usual rubbish now shown.
http://unique3phase.com/
I've mentioned these before but as this thread is about transformers it is worth repeating to keep all the information in one place.
Douglas Arndt is the inventor of "Unique 3 Phase" in America and Doug is a great guy to know; he is most helpful and full of enthusiasm and only too happy to help out with any problems that might arise. Rotary and static phase converters are covered in great detail as is making a large home welder. The information I was interested in though was using a transformer.
My initial attempt involved stripping a big electric motor to obtain the bare stator to use for the transformer laminations and this can be seen on the bench in the back ground of one of the pictures. I had some success with this ending up with 3 phase but by this time my enthusiasm knew no bounds and I was on a high. I visited our local scrap yard and obtained an old scrap 3 phase welding transformer which took two of us to lift into the car with a lot of effort; boy it was heavy.
Scrap transformer as bought.
Back home I struggled but eventually had the transformer on the bench in the garage and set about stripping it. I wasn't too gentle with the windings cutting straight through them with a sharpened power saw blade and hammer. I went gentler as the formers were approached and ended up with the laminations still retaining the three heavy plastic formers.
Stripping the old windings the easy way.
For the primary winding I used 1.5mm conduit wire and for the secondary's used 2.5mm conduit wire the wire bought from Screwfix in 100M coils. I viewed the relevant section of DVD over and over until I was sure I knew what I needed to do. I followed the DVD instructions to the letter having taken careful notes. By this time I had gained some useful experience winding radio chokes and transformers and even designed and wound two transformers to my own specification so at least I had good basic knowledge of how the transformer worked. What was new though was this being my first 3 phase transformer and the winding wire would take a lot of breaking.
The aim was to obtain 1.5V per turn and experimentation is called for as no data is available for these scrap transformers. I was amused by Doug's method of winding; only the two outer sections of the transformer are used and Doug had his son running a couple of blocks with the loose wire end as he added each turn. I was awake the whole of one night thinking about this as I was working totally on my own and it was snowing outside and not much better in the garage. I finally fell asleep with a solution that I thought would work. The following day I selected a strip of plywood about 4' long and notched the ends. The strip now to be called a "Shuttle" was given a good sanding to remove all sharp edges as it would be handled a lot. The shuttle would hold 100M of 2.5mm conduit wire and what a tremendous help this proved to be. By threading the shuttle containing the wire through the window of the laminations I found I could pass the shuttle through about 8 times then place the shuttle down whilst the turns were neatly arranged and pulled tight by hand.
Shuttle in action during winding.
I wound what I considered to be extra turns for the primary using the 1.5mm wire then I wound on a short length of 2.5mm wire making two turns and leaving both ends stripped of insulation as I would be taking voltage readings. This was something else new to me because I didn't know a transformer could be powered up with only the primary winding installed. The first reading was something like 3.6V but as two turns were wound on this gave 1.8V per turn which I thought to be brilliant but this was short lived. I had bought a clamp type ammeter and at this voltage the current at idle was too high; I disconnected from the supply and kept removing turns until I obtained a reading bang on 3V giving 1.5V per turn with a nice low idle of 0.8A.
Without giving too much away I then wound on the secondary windings using the 2.5mm wire and this was like working with stiff rope compared to winding a radio transformer. I didn’t need to experiment with the secondary winding as I could accurately work out the turns required from the 1.5V per turn primary reading.
I did have a few worrying moments at power up whilst experimenting with the primary winding as I had tapped into the mains 240V supply in the garage giving me a supply of 30A protected by a 30A MCB which tripped a number of times taking out the central heating boiler right in the middle of winter. I well remember it being a tense moment the first time I powered up as I didn’t know what to expect and given the sheer size of this transformer would the mains consumer unit destroy itself?
Winding completed.
I used Doug’s instructions and could connect and adjust the secondary voltages to give perfect readings of 415V on two legs as shown in the picture; this brought a huge smile to my face with a great sigh of relief. The third leg was wound at 600V which for a mechanical engineer is pushing it a bit; 600V with a push of 30A from the supply isn’t something I take lightly and I treated it with the utmost respect ensuring by checking and double checking the supply was disconnected each time I touched the transformer; I didn’t even trust it whilst taking the 3V readings.
Perfect 415V.
I’ve added these notes on 3 phase 415V just for interest and to show just how easy transformer winding can be to even the basic novice such as me. Using Doug’s method a transformer can be wound to give virtually any output at any voltage. I installed 3 phase 415V into my garage for just under £120 and still use it most times I go into the garage. I can power up a single machine or a number of machines up to an estimated 10HP on my system. Once the machines are phase balanced to the transformer it is just like having regular 3 phase installed and all the machines run on full power unlike using a phase converter.
Ready for installing into garage and fully installed and working.
I hope the above notes demonstrate just how easy and simple it is to either step up or down the 240V supply. I found playing around with the 3 phase to be quite addictive and very much enjoyed the learning curve ending up with extremely cheap 3 phase 415V in my garage that will power machinery up to around an estimated 10HP on full power.
I have previously owned a Transwave 7.5HP phase converter and right from the start never liked it as I had to keep setting the adjustments for each machine I had coupled up to it. My home made 3 phase dust extractor used to take ages to come up to speed and the big Colchester lathe I owned at the time didn’t half rattle the converter if I put on a heavy cut. The converter doesn’t put out full power either.
It’s worth mentioning that playing around with this kind of power is highly dangerous for a novice and a single mistake could easily prove fatal. High voltage capacitors are used for phase balancing and a bank of these needs treating with great respect as they can remain live and fully charged even though power is turned off. I made up a pair of well insulated prods with a high power 1K resistor in series and used these to discharge the caps every time before handling them and I even followed up with a voltage check each time using my DMM.
Whilst covering the subject of powering big machines at home I eventually over the years learnt how to wire 3 phase 415V modern six wire motors enabling them to run connected in “Delta” from the 240V supply using two capacitors and if I can find my notes I'll add the details; I also hope to add details on the practical side of transformer winding at home in the near future.
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
