RS, Farnell, CPC transformers

[McMurdo]

It seems the major uk suppliers RS, Farnell and CPC are dwindling their stocks of chassis mount transformers. I wanted some 6VA sizes the other day and had to get them from elsewhere.

Is this a warning that little transformers are going the way of CRTs?

[Uncle Bulgaria]

Rapid have 143 chassis mount transformers listed, so perhaps they are still geared towards the hobbyists a bit more. I wonder if RS in particular is getting more and more industrialised. Since their postage cost rejig it feels as thought it's harder and harder to get anything from them that doesn't have a minimum of thousands.

[DonaldStott]

Over the last few years I've benefited greatly as RS have a Trade Counter in Glasgow which saves a small fortune on postage and packing although that must be tempered by the current high cost of petrol and diesel.

Anyway I was ordering up some SMD capacitors as I often do for my work on hi-fi equipment but found that my usual choices were all on Back Order. Tried unsuccessfully to track down some alternatives and asked at the Trade Counter when they were expected to be back in stock. The very helpful chap contacted their supplier and was told April 2024!

[Craig Sawyers]

RS have a good range of 6VA chassis transformers. As do Rapid, but note that some are only a handful in stock and many more out of stock.

The vast majority are PCB mounting.

Craig

[Craig Sawyers]

I think that the dwindling in chassis transformers is that commercially it makes little sense. A chassis mains transformer involves hard wiring, almost few does any more. It leads to a very expensive construction technique.

If you were developing a new product that used a conventional mains transformer (ie not switched mode), you'd integrate it into an overall circuit board design.

Craig

[JonSnell]

Mouser are my current provider for Hammond transformers.
They are despatched from Mansfield.
I thought Mansfield UK but no, Mansfield USA!
They arrived within 2 days, no import duty nor delivery charges.
I was impressed and use them for all other transformers that I require.
Gone are the days that the UK produce anything. A real shame.

[McMurdo]

I wouldn't go that far, I did get the ones I wanted from german-owned distributor Rapid. Theirs are made in the UK by Blore-Bowron (Carnhill) and Vigortronix, both in Oxfordshire

[G6Tanuki]

It's true that lots of mainstream suppliers-to-the-trade are reducing the number of small traditional copper-and-iron transformers they stock.

For something like 15 years nobody has built new designs around such parts; this being driven by pressure to reduce energy-consumption.

Which was brought home to me back in 2009 whern I designed a simple bit of interface-gear that needed +12V@50mA and 5V@200mA - my initial design using a traditional transformer/bridge-rectifier/7805-and-7812 series-regulators drew six watts; a SMPS got this down to two watts, and the client got to tick the 'green credentials' box for his product.

So, yes, suppliers aren't offering a good range of small copper-and-iron transformers, becaue there's no demand!

[Chris55000]

There are quite a few in both traditional format and "R–Core" format, including ones with h.t. output voltages for valved circuitry, but the only slight snag being is that they're Chinese made!

They are still to be had on eBay, but everybody now calls all those stupid LED strip supply things "transformers!", so trying to find something that IS a traditional mains transformer is getting ever more difficult, as I found two months ago!

Make sure you look for "EI transformer", "R–Core" transformer, or select "Used" on the filters!

Chris Williams

[Welsh Anorak]

At Uni in the early Eighties a lecturer told us nearly all small mains adaptors would be switch-mode in the near future. We all looked at him in disbelief, wondering how the ubiquitous small 'wall-wart' could ever be replaced by these big scary devices. Took a while, though...