UK source for toroidal transformers
I found these people whilst surfin' around - Never used them before and have no connection to them, but their prices looked very good at a quantity break of 10 or more so a group buy could be very cost effective.
http://www.airlinktransformers.com/toroids.htm
I found these people whilst surfin' around - Never used them before and have no connection to them, but their prices looked very good at a quantity break of 10 or more so a group buy could be very cost effective.
http://www.airlinktransformers.com/toroids.htm
Funny..................
..........but this implies they sell in smaller quantities:
Standard Toroidal Transformer Range
VA Reg % Dimensions Wt Kg 1 2+ 10+ 25+ 50+ 100+
£ £ £ £ £ £
15 19 70x30 0.4 11.50 8.62 4.74 4.46 4.17 3.88
30 18 70x35 0.5 11.96 8.97 4.93 4.63 4.33 4.03
50 13 80x45 0.8 16.28 12.21 6.72 6.31 5.90 5.50
80 12 90x35 1.0 17.38 13.03 7.17 6.73 6.30 5.86
100 11 90x45 1.2 18.56 13.92 7.65 7.19 6.73 6.20
120 11 90x45 1.2 19.00 11.88 7.84 7.37 6.88 6.40
160 8 110x45 1.8 20.24 12.65 8.60 8.09 7.59 7.08
225 7 110x50 2.2 24.86 15.54 11.18 10.57 9.94 9.32
250 7 120x50 2.5 25.52 15.95 11.48 10.84 10.20 9.57
300 6 11x60 2.6 27.06 16.91 12.17 11.50 10.82 10.15
500 4 140x60 4.0 39.60 24.75 17.82 16.83 15.84 14.85
625 4 140x70 5.0 46.20 28.87 20.79 19.63 18.48 17.32
750 4 140x75 5.5 50.16 31.35 22.57 21.31 20.06
18.81
1000 3 160x70 8.0 63.80 39.87 28.71 27.11 25.52 23.92
1500 3 175x85 9.5 90.20 56.37 40.59 38.33 36.08 33.82
2000 3 190x90 15.0 114.40 71.50 51.48 48.62 45.76
2500 3 200x95 18.0 154.00 96.25 69.30 65.45
3000 3 240x105 21 220.00 137.50 99.00 93.50
5000 3 265x120 29 352.00 220.00 158.40
** Quantity Prices Are Exclusive of VAT **
Toroidal Transformer Technical Information
Toroidal Transformer Diagram
Toroidal transformers offer many advantages over a conventional laminated transformer. The circular tape wound core, with no air gaps, and with the primary and secondary windings uniformly distributed around the core, "locks in" the magnetic field and makes the toroidal transformer very quiet and efficient. As a result of this efficiency, Toroidal transformers are almost half the size and weight of EI or laminated transformers.
Toroidal transformers have an almost ideal physical construction and offer excellent technical performance. The height and diameter of the Toroidal transformer can be varied to meet customers special requirements.
All our Toroidal Transformers are manufactured in the UK at our own factory.
Our toroidal transformer are half the size of a conventional transformer
Quiet, ideal for Audio applications
Efficient typically 95%
Small and Light
Flexible
Flash tested to 4.5KV
Choice of resin centres to your requirements
So why post the price for 1 or 2+ or 10+ when you will not sell in those quantities???
Perhaps another few people calling them may may them change their minds!!!
Purchasing and Sales +44 (0)1279 602132
I was very impressed by the price break at 10+ units. Enought to make me hold off the eBay trannies.
How many could we do in a group buy. I will do either 2 or 4.
Cheers
Jon
..........but this implies they sell in smaller quantities:
Standard Toroidal Transformer Range
VA Reg % Dimensions Wt Kg 1 2+ 10+ 25+ 50+ 100+
£ £ £ £ £ £
15 19 70x30 0.4 11.50 8.62 4.74 4.46 4.17 3.88
30 18 70x35 0.5 11.96 8.97 4.93 4.63 4.33 4.03
50 13 80x45 0.8 16.28 12.21 6.72 6.31 5.90 5.50
80 12 90x35 1.0 17.38 13.03 7.17 6.73 6.30 5.86
100 11 90x45 1.2 18.56 13.92 7.65 7.19 6.73 6.20
120 11 90x45 1.2 19.00 11.88 7.84 7.37 6.88 6.40
160 8 110x45 1.8 20.24 12.65 8.60 8.09 7.59 7.08
225 7 110x50 2.2 24.86 15.54 11.18 10.57 9.94 9.32
250 7 120x50 2.5 25.52 15.95 11.48 10.84 10.20 9.57
300 6 11x60 2.6 27.06 16.91 12.17 11.50 10.82 10.15
500 4 140x60 4.0 39.60 24.75 17.82 16.83 15.84 14.85
625 4 140x70 5.0 46.20 28.87 20.79 19.63 18.48 17.32
750 4 140x75 5.5 50.16 31.35 22.57 21.31 20.06
18.81
1000 3 160x70 8.0 63.80 39.87 28.71 27.11 25.52 23.92
1500 3 175x85 9.5 90.20 56.37 40.59 38.33 36.08 33.82
2000 3 190x90 15.0 114.40 71.50 51.48 48.62 45.76
2500 3 200x95 18.0 154.00 96.25 69.30 65.45
3000 3 240x105 21 220.00 137.50 99.00 93.50
5000 3 265x120 29 352.00 220.00 158.40
** Quantity Prices Are Exclusive of VAT **
Toroidal Transformer Technical Information
Toroidal Transformer Diagram
Toroidal transformers offer many advantages over a conventional laminated transformer. The circular tape wound core, with no air gaps, and with the primary and secondary windings uniformly distributed around the core, "locks in" the magnetic field and makes the toroidal transformer very quiet and efficient. As a result of this efficiency, Toroidal transformers are almost half the size and weight of EI or laminated transformers.
Toroidal transformers have an almost ideal physical construction and offer excellent technical performance. The height and diameter of the Toroidal transformer can be varied to meet customers special requirements.
All our Toroidal Transformers are manufactured in the UK at our own factory.
Our toroidal transformer are half the size of a conventional transformer
Quiet, ideal for Audio applications
Efficient typically 95%
Small and Light
Flexible
Flash tested to 4.5KV
Choice of resin centres to your requirements
So why post the price for 1 or 2+ or 10+ when you will not sell in those quantities???
Perhaps another few people calling them may may them change their minds!!!
Purchasing and Sales +44 (0)1279 602132
I was very impressed by the price break at 10+ units. Enought to make me hold off the eBay trannies.
How many could we do in a group buy. I will do either 2 or 4.
Cheers
Jon
I'm afraid as I have mentioned above that I have already managed to get my transformers for this project (proabably too many as well at four of them) so I won't be able to chip in on this one. However I would still like to get in on a group purchase of MOSFETS, power resistors and probably heatsinks (from conrad), if those are going ahead. Especialy as I am considering getting heatsinks from there on any case (and I guess my credit card could stand up to a reasonable group buy from australia if other people wanted some too).
CONRAD HEATSINKS
Hi ...... well I have decided....I am definately going for the conrad heatsinks.......I am going for the double flanged....this will assist construction and ensure that the heatsink does not warp (this can be a big problem) I intend to use 16 output devises per channel (8 on each sink).
Maybe the 150mm high varient may suite bigparsnip?
I intend to build two mono blocks so I will order 4.
However I am going to hold on until the circuit boards arrive! I believe 'bigparsnip' is correct these sinks are good quality.
I would like to share the shipping 'bigparsnip' are you a runner on this......does anybody else want to joint in.
Regarding matched mosfets......I recon the best way would be to get a bulk order going..........then we would be able to match sets
.....we could probably get mosfets for under £2 each......
Richard Bolton uk
Hi ...... well I have decided....I am definately going for the conrad heatsinks.......I am going for the double flanged....this will assist construction and ensure that the heatsink does not warp (this can be a big problem) I intend to use 16 output devises per channel (8 on each sink).
Maybe the 150mm high varient may suite bigparsnip?
I intend to build two mono blocks so I will order 4.
However I am going to hold on until the circuit boards arrive! I believe 'bigparsnip' is correct these sinks are good quality.
I would like to share the shipping 'bigparsnip' are you a runner on this......does anybody else want to joint in.
Regarding matched mosfets......I recon the best way would be to get a bulk order going..........then we would be able to match sets
.....we could probably get mosfets for under £2 each......
Richard Bolton uk
Attachments
Hi, yes I would be interested in sharing the shipping costs as I would like to try and order a few sinks for myself, namely the:
MF35-50 x 2
MF35-75 x 4
MF35-151 x 2
the only minor worry I have with this is what costoms will be like witht the parcle, and how much extra in import duty and VAT we may have to pay. But, if you want to wait till the boards arive that would be fine as that should hopefuly be happening in the next week or so.
MF35-50 x 2
MF35-75 x 4
MF35-151 x 2
the only minor worry I have with this is what costoms will be like witht the parcle, and how much extra in import duty and VAT we may have to pay. But, if you want to wait till the boards arive that would be fine as that should hopefuly be happening in the next week or so.
import duty............
Thought this extract would be of interest.........
Import Duty
Duty is calculated on the declared invoice value of the goods (even if a gift) entering the EC. Universities may apply for relief from import duty for scientific instruments imported for educational purposes or non-commercial scientific research. Donated medical equipment, if imported for medical purposes, may also be exempt from import duty. Applications for duty relief must be made to the Department of Trade and Industry through the Purchasing Office. It is unlikely for Duty relief to be granted if the DTI decide that like items can be obtained from within the EC, regardless of cost.
VAT
All goods, whether from EC or non EC countries, entering the UK are liable for VAT (currently 17½%) which is added to the total of the declared invoice value and any applicable import duty. This applies regardless of whether the University is purchasing the goods, hiring them or receiving them as a sample or a gift.
Medical, scientific, computer, video, sterilising, laboratory or refrigeration equipment for use in medical research, training, diagnosis or treatment are exempt from VAT. (see section 7000 - Relief from Value Added Tax). When this applies, the shipping agent will require a copy of the order with the proper VAT exempt certification prior to arrival of the goods. Failure to comply will result in the payment of VAT on importation following which it is very difficult to obtain a refund.
Imports by Post
The Post Office will not release imported parcels until duty and VAT have been paid in full, even if duty relief has been granted or if VAT exemption applies. Departments may obtain cash against their account from the Cash Office in the Finance Office to cover this. If duty relief has been granted or has been applied for, and/or VAT exemption applies, you should retain the part of the packaging which carries the Customs declaration and stamp in order to reclaim duty or VAT. Purchasing can assist in this matter.
Thought this extract would be of interest.........
Import Duty
Duty is calculated on the declared invoice value of the goods (even if a gift) entering the EC. Universities may apply for relief from import duty for scientific instruments imported for educational purposes or non-commercial scientific research. Donated medical equipment, if imported for medical purposes, may also be exempt from import duty. Applications for duty relief must be made to the Department of Trade and Industry through the Purchasing Office. It is unlikely for Duty relief to be granted if the DTI decide that like items can be obtained from within the EC, regardless of cost.
VAT
All goods, whether from EC or non EC countries, entering the UK are liable for VAT (currently 17½%) which is added to the total of the declared invoice value and any applicable import duty. This applies regardless of whether the University is purchasing the goods, hiring them or receiving them as a sample or a gift.
Medical, scientific, computer, video, sterilising, laboratory or refrigeration equipment for use in medical research, training, diagnosis or treatment are exempt from VAT. (see section 7000 - Relief from Value Added Tax). When this applies, the shipping agent will require a copy of the order with the proper VAT exempt certification prior to arrival of the goods. Failure to comply will result in the payment of VAT on importation following which it is very difficult to obtain a refund.
Imports by Post
The Post Office will not release imported parcels until duty and VAT have been paid in full, even if duty relief has been granted or if VAT exemption applies. Departments may obtain cash against their account from the Cash Office in the Finance Office to cover this. If duty relief has been granted or has been applied for, and/or VAT exemption applies, you should retain the part of the packaging which carries the Customs declaration and stamp in order to reclaim duty or VAT. Purchasing can assist in this matter.
Take a look at these capacitors.........computer grade
from http://www.apexjr.com/capacitorsR.html
from http://www.apexjr.com/capacitorsR.html
Attachments
i like the pricing for those from BG micro, and I would quite happily take 20 (or more) for myself if anyone else wanted to get some too.
edit:
actualy, it would make more sense to buy more of these now as they are rated at a high enough voltage to use in other projects. So I guess I could easily take 40 just for me, which would mean that the cost would only be £1.80 each (pluss whatever the postage would come to for shipping them, but that is still a great price for such big caps).
Let me know if anyone els is interested in them and I can send a mail to BG micro asking how much the shipping will be.
edit:
actualy, it would make more sense to buy more of these now as they are rated at a high enough voltage to use in other projects. So I guess I could easily take 40 just for me, which would mean that the cost would only be £1.80 each (pluss whatever the postage would come to for shipping them, but that is still a great price for such big caps).
Let me know if anyone els is interested in them and I can send a mail to BG micro asking how much the shipping will be.
right, so that would be some for you and some for me (say 50 in total) so I'll get in touch witht them and see how much postage and stuff will be. If anyone else wants to get in on this let me know and I'm sure the price won't change too much from this sort of order quantity,(unless something happens to the postage costs at some point).
NOt quite arc welding, but as I have four boards, that need four seperate supplies That would be a minimum of eight. However, I intend to run CRC filters so that jumps up to 16 caps. I also have another amp project running (although I think these may just be slightly under the necessary voltage) so that will be another four to eight for that. Then, just to make sure I do haev enough add some more on to get your final figure.
Besides at that price who could resist.
Besides at that price who could resist.
Re: caps
A CRC filter is a trick that you can use to help smooth your supply rails out a bit more than the capacitors could manage on their own. What you have to do is attach the first capacitor straight after your diode bridge. Then instead of wiring the next cap straight onto the positive trminal of the first cap, you wire in a resistor between the two.
Using this method does dissipate some extra heat in your resistors, and will mean you lose a little voltage due to the drop accross the resistor, but it does mean a more uniform set of supply rails which can only be good.
You can acheive a similar result using large inductors, which are more efficient and waste less power, but they would cost a lot more to buy, so for now I'll just stick with the power loss in the resistors.
D3 said:
A CRC filter is a trick that you can use to help smooth your supply rails out a bit more than the capacitors could manage on their own. What you have to do is attach the first capacitor straight after your diode bridge. Then instead of wiring the next cap straight onto the positive trminal of the first cap, you wire in a resistor between the two.
Using this method does dissipate some extra heat in your resistors, and will mean you lose a little voltage due to the drop accross the resistor, but it does mean a more uniform set of supply rails which can only be good.
You can acheive a similar result using large inductors, which are more efficient and waste less power, but they would cost a lot more to buy, so for now I'll just stick with the power loss in the resistors.
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