[GreenKeys] Looking For Bits

[Keelan Lightfoot]

Jim,

Thanks for taking the time to research these. I went down the same path with Mouser and Digikey; non-stock probably means an expensive minimum order quantity. I probably wouldn't order from Mouser, they certainly don't go out of their way to serve Canadian customers. On my last order, I ended up paying $40 in shipping and duty on a $70 order.

Newark seems like it might be an option, I can't find any mention of a minimum order on their web site. Maybe they're trying to keep up with the competition. I'll take a look into them. I was just thinking, the local electronics shop has a bunch of Hammond transformers in their discount bin. There aren't any that directly suit what I'm looking for; but they have a couple 44VAC transformers that would work nicely with their secondaries series.

- Keelan


On 2011-08-28, at 12:05 PM, Jim Pruitt wrote:

> Hello Keelan:
> 
> Looks like a Hammond 187C120 at 12VA would more than do it for you.  At least looking at their spec sheet pages from
> <http://www.hammondmfg.com/186_187.htm> .
> Mouser lists them but it is a non stock item at less than $10 at
> <http://www.mouser.com/ProductDetail/Hammond-Manufacturing/187C120/?qs=sGAEpiMZZMv4oUrzpPKU3CkdIda8KQx%252bPVHaKkfyINc%3d> .
> Digikey also lists them at $10.68 but again a non stock item at
> <http://parts.digikey.com/1/parts/1957156-transformer-chassis-mount-187c120.html> .
> I do not know if you could order one from Hammond directly or not.  Newark says they currently have 28 in stock at $11.49 at
> <http://www.newark.com/hammond/187c120/power-transformer/dp/50H6562>
> each (but Allied and Newark have a minimum order of $50 or used to).
> 
> Jameco lists a stock number 221331 Isolation transformer but at almost $60 at
> <http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&productId=221331&catalogId=10001&freeText=221331&app.products.maxperpage=15&storeId=10001&search_type=jamecoall&ddkey=http:StoreCatalogDrillDownView> .
> 
> Mouser I think has the 120vac pri 120vac seconday at 50ma transformers as they seem to get used a lot in old AA5 and similar radios so that is just a bit shy of your 60ma requirement if you go with a 60ma loop.
> 
> The other thing is as you suggested and put two transformers back to back.
> 
> Good luck.
> 
> Jim Pruitt
> 
> 
> 
> ----- Original Message ----- From: "Keelan Lightfoot" <keelan at mail.grenander.com>
> To: <maflynn at theflynn.org>
> Cc: "Green Keys" <greenkeys at mailman.qth.net>
> Sent: Saturday, August 27, 2011 8:10 PM
> Subject: Re: [GreenKeys] Looking For Bits
> 
> 
>> 120V, 10VA-ish. A transformer with a few taps would be handy, as 160VDC seems a bit high for my liking. A 90V tap would give me somewhere in the range of 135VDC after rectification, which is more the level I am looking for.
>> 
>> - Keelan
>> 
>> On 2011-08-27, at 8:01 PM, Martin A Flynn wrote:
>> 
>>> What voltage and how many watts?
>>> 
>>> Martin
>>> 
>>> On 8/27/2011 10:52 PM, Keelan Lightfoot wrote:
>>>> I'm looking to buy:
>>>> 
>>>> 3. A 1:1 isolation transformer suitable for loop supply use. It would seem these are quite hard to come by, even in the form of old shaver outlet isolation transformers. I can get away with a couple transformers back-to-back, but I'd like to do it in a cleaner way if possible.
>