LPSU choices, new contender.....

[Superdad]

14 minutes ago, mansr said:

Hand assembly is not difficult either if you stick to 0402 or larger parts.

 

0402 size parts are really a pain to hand place and solder.  Unless you like to spend all day with you face on a microscope.  For prototyping (not large production), clever folks built their own pick-and-place machine.  Couple with a small vapor-phase reflow oven it makes for beautiful boards.  

 

 

[Superdad]

39 minutes ago, mansr said:

If you can't place 0402 parts, your hands are simply not sufficiently resolving.

 

The challenge is getting them out of the tape without all those tiny unmarked specks flying across the floor. 

[Superdad]

7 minutes ago, jabbr said:

...pick your poison 

 

Bourbon or rye thanks.  (though never just before soldering)

[Superdad]

1 hour ago, sandyk said:

 

 Was Radio Shack ever a REAL contender for anything other than mundane parts ?

 

Don't be dissin' the Shack man!  

In my youth I bought parts for my color organs and then later TRS computers.  Plus spare parts in a pinch.  They were no Allied Radio, but hey, they were open on Friday evening and the weekends.

[Superdad]

3 hours ago, 4est said:

I've been quietly promoting split bobbin xfmers (and choke input filters) here for many years. 

 

I'm a fan of split bobbin trans too, but good luck finding then in anything larger than 48VA.  And they often are mechanically noisy (lam buzz) when you pull real current through then.  Unlike R-cores, which have near the performance, lower flux field radiation, are available in larger sizes--and are DEAD SILENT!

[Superdad]

29 minutes ago, Ralf11 said:

ok, re good snubbers on the diodes....  what makes it 'good'?

 

is this a noise issue in the snubber diode itself?  or a regulation, or breakdown issue?

 

No, I think Jonathan is just talking about well chosen values for an RC network to place across the trans secondaries (or diode bridge--same thing) to kill transformer ringing. Special parts not needed. 

[Superdad]

1 hour ago, Jud said:

It would be nice for me personally and I'm sure others to get some tips regarding what components one might expect to see in a quality LPSU, if we're thinking of purchasing one.

 

Well ideally something better than $0.50 potted bridge rectifiers and ancient LM317 regs coupled with pass transistors and high wattage resistors.  [That's the design of the PSU that this threads was started with. Many of the Chinese units will be much quieter, those those suffer from not being able to produce their rated output currents.]

[Superdad]

3 minutes ago, jabbr said:

The fact that we are communicating despite the fact that you are upside down is all the substantiation needed.

 

I was about to unsubscribe to this wildly off-topic, going nowhere thread, but that's funny! 

 

(Someone please remind me again: Does water spiral down really spiral down the drain in the opposite direction in Australia?)