Opinion needed: 12V ± supply, low power, <100mA

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,086
Sounds good to me. :cool:
Yeah, was a pleasure last night watching Green Bay beat Chicago Bears.
How about using two of these- then power it with a tiny 5V USB power supply?

https://www.digikey.com/en/products/detail/cui-inc/PDSE1-S5-S12-S/10229828

$4.30 for the two?
Pretty nice. However, there seems to be some ESD concerns with them. Besides, I already have everything I need to build. No buying, no shipping. But definitely worth keeping in mind. Another concern with DC to DC converters is the potential noise. Though I didn't read the data sheet fully, I would be concerned. 60 cycle AC can be easily filtered out. And since this PUC (Project Under Consideration) is a visual deal it will be similar to looking at a noise signal on an oscilloscope. It might be fine to use that device, but primarily, I have the stuff needed to build. But thanks for that. It's information worth keeping.
 

sparky 1

Joined Nov 3, 2018
566
@Tonyr1084
Please look at the datasheet, one of several examples. was mentioned double secondary.
I think these are 230V uk ? the secondary minus regulator drop not the no load. 44124 cost about 8 Euros
( I use 28VCT it is for 117V USA name is "signal core" DP-241-5-28 I use it for +/-12VDC) I prefer LM317 for positive pole because I can trim it up or down.
I am sure there are many different ways mine requires pre-regulator for quieter operation 20% more VA for cooler 44125* or two secondary 44131**
http://www.farnell.com/datasheets/41249.pdf
 
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Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,086
I'm in the (dis)United States of America. Will be using 120VAC line into the transformer. The transformers I linked are 120 to 6.3 - 0 - 6.3VAC.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,086
OK, Y'all, have a go at me over this one. I don't "KNOW" these values are correct, I'm just using things I've seen on the internet. Could really use your critical eye. But one point I'm asking you to remember, I have these components. As far as values of pots, resistors, caps and diodes as well as the chip afore mentioned somewhere, this thread or another, this is what I think will achieve my goal.

Remember, the output is going to drive a small laser pointer pointing at a tilted mirror on the end of a small motor creating a circular beam pattern on the wall. The laser will be pulsed by an audio signal. So I'm going for an XYZ effect where X and Y create the circle and Z creates positive going visual effect. In other word, you're looking down on the top of the Y axes and every time the sine wave goes positive you see the tops of the wave. You don't see the troughs. I'm sure my explanation is lacking, but try to think in three dimensions and position yourself over the Y axes of a normal trace. Every time the current is forward going you see the trace. When it goes negative you don't see it. This produces a series of dots or dashes, depending on the audio signal.

Well, here it is - let me know if I missed something or if something is out of sorts. I'm open to criticism.
1606780875731.png
 
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