27 Jun
2013
27 Jun
'13
7:01 p.m.
On 6/26/2013 6:02 PM, Jim Brain wrote:
I would agree that a direct-on-line SMPSU is probably not a good thing to
offer as a kit. One small mistake is assembly (e.g. a dry joint on the
'right' compoennt) and the result at switch-on wil leb spectacular.
Essentially a dead short across the maisn with components blown off the PCB.
On the other hand, a mains trandormer giving out 9V AC follwed by a
swichign regualtor to cut it down to 5V is, IMHO a suitable project or
kit. You are workign with safe, low, voltages and if you do make a mitake
while you mioght well burnt out the chopper transistor or control IC, you
will not end up with a major disater.
It is for these reasons that I would not offer a
PSU kit. My apologies,
but I don't think I'd ever be comfortable in that situation.
The only power supply stuff I have seen has been Transformer Choke
Cap stuff. Switching stuff I leave to the Chinese clones.
> Pragmatically, kits do not bring me joy in general. I spend more time
It can work both ways. In general the only people to buy kits have at
least am inor clue, so you don't get the really silly support quesitons.
Personalyl, though, I learnt the hard way not to supply jus the
programmed parts and a scheamtic. You get idiots who conenct power lines
backwards and expect free replacements of the ICs.
I think now all I would offer is a scheamtic (and PCB layout, chassis
layout, etc). Labelled 'Experminatal Deisng Only'.
helping folks
debug them, and I charged less to sell them in the first
place. Ready made units require less support. I know that's heresy to
the folks on this list, but it is the truth. For every soldering guru
on here with an armful of databooks and a scope, there's hundreds of
people in this classic machine community who treat a electronics kit
like a "snap-tite" plastic model.
But then that is what all they sell 'plastic model' kits today.
Learn *Bla Bla Bla" with this flashing led kit.