Reply by Bill Sloman November 17, 20192019-11-17
On Monday, November 18, 2019 at 9:05:25 AM UTC+11, Clifford Heath wrote:
> On 18/11/19 3:28 am, Winfield Hill wrote: > > Bill Sloman wrote... > >> > >> this is sci.electronics.design, not > >> sci.electronics.slap-together-something-that-sort-of-works. > > > > Sometimes, slap-together-something-from-parts-at-hand, > > that-works-just fine, is not a bad approach. Engineers > > can do the calculations, to get a clear understanding > > of whatever tradeoffs are being made, and the margins, > > then we needn't be ashamed of making a few tradeoffs. > > I would go further than that. Design *is* tradeoff. Finding the right > compromises is absolutely central to the work of designers in any field.
But it's an informed trade-off. You need to know what a purpose built transformer could do for you before can work out how much that trade-off is costing you. -- Bill Sloman, Sydney
Reply by Clifford Heath November 17, 20192019-11-17
On 18/11/19 3:28 am, Winfield Hill wrote:
> Bill Sloman wrote... >> >> this is sci.electronics.design, not >> sci.electronics.slap-together-something-that-sort-of-works. > > Sometimes, slap-together-something-from-parts-at-hand, > that-works-just fine, is not a bad approach. Engineers > can do the calculations, to get a clear understanding > of whatever tradeoffs are being made, and the margins, > then we needn't be ashamed of making a few tradeoffs.
I would go further than that. Design *is* tradeoff. Finding the right compromises is absolutely central to the work of designers in any field.
Reply by Winfield Hill November 17, 20192019-11-17
Bill Sloman wrote...
> > this is sci.electronics.design, not > sci.electronics.slap-together-something-that-sort-of-works.
Sometimes, slap-together-something-from-parts-at-hand, that-works-just fine, is not a bad approach. Engineers can do the calculations, to get a clear understanding of whatever tradeoffs are being made, and the margins, then we needn't be ashamed of making a few tradeoffs. -- Thanks, - Win
Reply by Bill Sloman November 16, 20192019-11-16
On Sunday, November 17, 2019 at 2:21:52 PM UTC+11, Winfield Hill wrote:
> Bill Sloman wrote... > > > > John Larkin is convinced that you ought to use off-the-shelf > > transformers wherever you can, rather than designing something > > for your particular job and having it made. > > > > Transformers have a lot of parameters you can adjust ... > > I have designed dozens, if not hundreds, of custom > transformers, most of which were laboriously made > by my technician, R.I.P.
You can wind your own prototypes - you do need a coil winding machine with a turns counter, but they aren't big or expensive.
> And many were made for me > by local transformer companies, also R.I.P.
It's a good ten years since I had a transformer made, when I was still in Nijmegen , and it took me a bit of hunting to find a coil winding shop, about forty minutes drive away, in Venlo. They still seem to exist. These days, there's probably a Chinese supplier, and Sphero Pefany could probably tell us if they were any good.
> And I've > amassed a huge inventory of cores and bobbins of all > types, along with their relevant data. But, like > John, I'm a huge fan of re-purposing off-the-shelf > parts, if possible.
Me too. But it often isn't possible, even if you are prepared to live with a decidedly sub-optimal transformer.
> So I also have a huge collection > of candidate parts, ready to be evaluated. I won't > be criticizing anyone who wants to go down that path.
My feeling is that you always need to look at what a purpose-wound transformer would look like. You won't get a feel for what's attainable, or important, until you've done it. That may be a counsel of perfection, but this is sci.electronics.design not sci.electronics.slap-together-something-that-sort-of-works. -- Bill Sloman, Sydney
Reply by Winfield Hill November 16, 20192019-11-16
Bill Sloman wrote...
> > John Larkin is convinced that you ought to use off-the-shelf > transformers wherever you can, rather than designing something > for your particular job and having it made. > > Transformers have a lot of parameters you can adjust ...
I have designed dozens, if not hundreds, of custom transformers, most of which were laboriously made by my technician, R.I.P. And many were made for me by local transformer companies, also R.I.P. And I've amassed a huge inventory of cores and bobbins of all types, along with their relevant data. But, like John, I'm a huge fan of repurposing off-the-shelf parts, if possible. So I also have a huge collection of candidate parts, ready to be evaluated. I won't be criticizing anyone who wants to go down that path. -- Thanks, - Win
Reply by Bill Sloman November 16, 20192019-11-16
On Wednesday, November 13, 2019 at 4:37:07 PM UTC+11, Sjouke Burry wrote:
> On 13.11.19 3:32, -asop- wrote: > > I am looking into making a circuit that will essentially use a high > > current flyback transformer. I'd like to use the one here: > > > > https://www.amazing1.com/products/high-voltage-switching-transformer-4000-turn-coil-of-37-wire-40kv-30ma-15k-60khz-large-core.html > > > > However, after ordering from this firm in the past, after I received the > > part, I was able to find it online from a different firm a lot cheaper. > > I'd like to know if anyone knows of any equivalent transformers at a > > cheaper price. > > > There is a correlation between quality and price.
There a rather stronger correlation between production volume and price - if you can find a part that is being used in large volume for a different application you can almost always get it cheaper than you would if you had it made just for your application. John Larkin is convinced that you ought to use off-the-shelf transformers wherever you can, rather than designing something for your particular job and having it made. Transformers have a lot of parameters you can adjust during the design process (if you understand what you are doing, which John Larkin may not be able to manage for transformers) so the purpose built part tends to be a lot more cost effective than the nearest off-the-shelf part. You can get lucky, but I mostly ended up designing the (few) transformers that I needed. -- Bill Sloman, Sydney
Reply by Sjouke Burry November 13, 20192019-11-13
On 13.11.19 3:32, -asop- wrote:
> I am looking into making a circuit that will essentially use a high > current flyback transformer. I'd like to use the one here: > > https://www.amazing1.com/products/high-voltage-switching-transformer-4000-turn-coil-of-37-wire-40kv-30ma-15k-60khz-large-core.html > > However, after ordering from this firm in the past, after I received the > part, I was able to find it online from a different firm a lot cheaper. > I'd like to know if anyone knows of any equivalent transformers at a > cheaper price. > > Thanks. >
There is a correlation between quality and price.
Reply by -asop- November 12, 20192019-11-12
On 11/12/19 9:32 PM, -asop- wrote:
> I am looking into making a circuit that will essentially use a high > current flyback transformer.  I'd like to use the one here: > > https://www.amazing1.com/products/high-voltage-switching-transformer-4000-turn-coil-of-37-wire-40kv-30ma-15k-60khz-large-core.html > > > However, after ordering from this firm in the past, after I received the > part****, I was able to find it online from a different firm a lot cheaper. > I'd like to know if anyone knows of any equivalent transformers at a > cheaper price. > > Thanks.
****Just to note that this was for a different part, not the transformer I linked to.
Reply by -asop- November 12, 20192019-11-12
I am looking into making a circuit that will essentially use a high 
current flyback transformer.  I'd like to use the one here:

https://www.amazing1.com/products/high-voltage-switching-transformer-4000-turn-coil-of-37-wire-40kv-30ma-15k-60khz-large-core.html

However, after ordering from this firm in the past, after I received the 
part, I was able to find it online from a different firm a lot cheaper. 
I'd like to know if anyone knows of any equivalent transformers at a 
cheaper price.

Thanks.