Need small footprint simple single 12 VDC supply
Howdy...These linkswitch devices look great. However they are often designed around customer little xformers. This cannot work for me. I need (my clients) to be able to source the xformer from a parts supplier like Digikey. So I need the smallest footprint possible for a ACDC single 12VDC supply that has a capability of 200mA to 350mA. Anywhere in that range should do. I was looking at DER186. Looked great! Then saw the custom xformer and that was a deal killer. Can anyone help with guidance? Many appreciations...
BTW... Power Integrations website apparently did a hiccup and I observed (today) multiple posts from me. I cleaned out the annoying repetition posts. :)
Comments
There are same transformer vendors that they make off the shelf transformers. http://www.powerint.com/en/design-support/component-suppliers In the past i worked with premier magnetics and they had good stock on transformers for PI. http://www.premiermag.com/
Thanks for your reply... So here's the thing.
1. I used the PI software and entered in my specs, and it spit out a design, with custom xformer of course.
2. I checked the xformer sites that the tool directed me to. It is not CHEAP to get even a sample made. Costs hundreds of dollars for 1 or a couple samples, and long lead time, unless I want to pay even more. Moreover I did not get the rosy feeling that if I ordered 100 or 1000 of these xformers, that I was going to get them under 20 bucks each.
3. For $6 on Amazon I can buy a (small) simple ACDC wall adapter (switching power supply unit from China) that is complete PSU and does the same job. This does not compute.
If PI tool cannot point design engineers to CHEAP and ready off-the-shelf xformers, then this is just a complete waste of time. At the end of the day, it is difficult to explain to my clients who need a (little) on-board power supply have to pay more than 10x more just in parts alone (primarily because of the xformer) than a simple wall unit in China (which they would use if they could).
Just my 2 cents...
Still feel I have no solution... Costs too much to use PI parts IMHO. :(
Premier magnetics has off of the shelf transformers
did you check them?
Hi PI-Worf... Thank's for highlighting this organization. I went to their website. They appear do have xformers with certain output capacities. There is no way to purchase however. One has to go through a live sales channel where they ask you to name "your target price" and how many you expect will need. This is hardly akin to going on a Digikey and merely ordering. This implies (to me from experience) that it will not be cheap. Needless to say, I'm giving this a try. I have contacted the organization requesting pricing for 1-2 samples, then 100, then 1000 when full production starts. I'll let you know how this goes...
Just so you know, the ONLY reason I need this 12V ~400-500 mA supply is to run an Arduino Uno and a LCD (which is more power hungry than the Arduino). The rest of the (high voltage) controller derives its own power directly from the line.
Incidentally Digikey does offer xformers ready for LNK devices, but none of these xformers are spec for over 100mA (which is kind of silly in my humble opinion). Since the xfomer is the backbone of the power supply, it need not break the back of the design engineer to get a product out the door that needs to be cheap. Silly to make a PSU for 50 bucks when one can buy one for $6. Sigh...
I am sorry for your unpleasant experience with premier magnetics. I did not know now they works this way. Before, when I used this site, I just select my part and bought it. No question asked.
Anyway I do know if the other vendors listed in the webpage work in the same way. I am out of suggestion. Transformers are not as other components that are produced in millions and sold in large quantities. So it may be difficult to find off the shelve parts
Darn it... Just re-evaled my 12V current requirements more carefully. I need about 500mA. Perhaps a tinyswitch cannot muster this with an off-the-shelf xformer?