a little help with capacitive power supply values

[Dennis]

Hi guys
With reference to post #66 and the rest that follow and everything else prior to it.

Interesting indeed !

Keith ..AWESOME reply!

I agree with you here

triac is switching the live supply to the load.

Ok now for the beginning of the mystery and to add to this threads confusion you added this in :-)

If the circuitry was common neutral then the triac would also be switching neutral with the result that the entire load would be live when the circuit appeared to be OFF.

So from that statement we should assume COMMON LIVE is the supply of choice (in terms of being a little safer) not COMMON NEUTRAL ? Assuming of course that this circuit is indeed a COMMON LIVE circuit ?

Any comments on the above statements ?

Steve ....

Nice...! You threw in another side-winder, in fact, you mentioned something very real !
A two prong(pin) plug in most countries (correct me if I'm wrong ?) is easily reversed , in other words pluged in the other way around .. both sides same sides kind of thing so if I decide to design my PSU with the left prong as LIVE and the right prong as NEUTRAL .. all fine and dandy but then I unplug the device, put the pulg into the wall socket the other way around and suddenly everything is changed around :-)
Does this mean I should re-design my whole circuit ?
UH OH !

Well I encountered this dilemma a few nights back ... just before I got the broomstick, earmuffs and rubber gloves out and got all kitted up, I thought "Gee on this two-prong plug what happens when everything turns around ?"
"Will the circuit blow? What will the effect be? Will I need to change everything?"

So it works , turned either way around ! ( AC @ 50 Hz hmmm? )

And ..on the safety side is this circuit any less dangerous than a lamp that takes a bayonet or screw in light bulb ? Let's face it there is 110/120VAC or 220/230/240VAC right at the contacts where you screw the light in , not so ?

What about the computer AT form not so long ago which had mains voltage right at the front panel pretty much like may household appliances,TV's and radios before soft-power switches became the flavour of the day.

OK my next mission would be to alter the circuit so that the 'circuit ground' is the LIVE line in the schematic but .. do I really need to ?

Awaiting more comments and thoughts :-)

Oh and the question still remains ... is the circuit in post # common live or common neutral ? and why ?

Kind regards

Dennis

[keithdoxey]

Keith ..AWESOME reply!

So from that statement we should assume COMMON LIVE is the supply of choice (in terms of being a little safer) not COMMON NEUTRAL ? Assuming of course that this circuit is indeed a COMMON LIVE circuit ?

Living in a country where every mains outlet is a 3 pin socket so polarity reversal is impossible unless the actual outlet is incorrectly wired I would say that common live *should* be the supply of choice particularly if the load it was controlling was external to this box of tricks so that it would be recieving a correctly switched supply.

Irrespective of supply polarity, becuase this circuit is tied directly to one leg of the mains supply it should be totally enclosed and should never be worked on except via an isolation transformer.

All "basic" light dimmers have a common live supply as they are only connected to the live and load.

[Dennis]

Hi again

Nice one keith ...safety and isolation for sure! Have you read the earlier posts ?

Living in a country where every mains outlet is a 3 pin socket so polarity reversal is impossible unless the actual outlet is incorrectly wired I would say that common live *should* be the supply of choice particularly if the load it was controlling was external to this box of tricks so that it would be recieving a correctly switched supply.

And those plugs quite often contain fuses (probably on the LIVE) not so ?
And the looking at the APPNOTE that I referred to in post #1 under the designing for safety heading you would see the fuse placed on one of the lines as well as a fuse and a bleeder/'safety' resistor sitting parallel with C1.

Now let's chat about the 2 prong device that need to be plugged in the countries you're referring to.
We need some sort of adapter to plug the 2 prong device into the 3 prong plug right ? Does th adapter contain a fuse as per country electrical regulations (if any ) ?
So again plugging a PSu like this one into the adapter, one can plug in either way ... and yet again NEUTRAL and LIVE are switched around (in the circuit of course)!

If this indeed is the case then we are right back at the million dollar question
"Is this circuit Common LIVE or COMMON NEUTRAL ? And why ?"

And then we must look at the designing for safety aspects where we discussed fuses.
One of the original draughts had two fuses , one on each line, and a point or two were raised about one of the fuses (the one on the neutral line) would be pointless. Yes indeed it probably would be useless as well as unsafe ...IF this circuit contained an earth(real ground) !
But alas, the circuit has no earth point or connection at all !

SO it seems this circuit will always 'FLOAT' either at 5volts(or whatever you designed it for) below live or 5Volts above neutral.
In earlier posts I showed circuit diagrams of common live and common neutral from various references.Circuits with components changed around, in different places forcing flow in different directions.
Are these circuits incorrect ?

Sadly I don't have an oscilloscope or an isolation transformer at my disposal anymore but I certainly will check/test/build blow-up each circuit depicted and feedback so we can continue this discussion.

Anyone feel like building a calculator to calcualate the APPNOTE referred to in post #1 and/or the circuit in #66 ?

Regarding the 'BOX OF TRICKS' you mention ...

If all of you that are following this post have some time , go and google for 'Ben Franklin flyng a kite in the rain with a key tied to the string' to attract lightening strikes.

And then along the lines of safety and climate change try google H.A.A.R.P.

Sure... why not try heat the ionosphere at it's thinnest points at the poles to blow a hole in it just to see what happens .. now that's safety for all mankind not so ?

All thanks to folks like Tesla, Franklin and ...aaargh let's not go there!

And is the H.A.A.R.P experiment over ... well apparently (will we ever really know?), but google earth and satellite pics show the facility plain as day !

Oh well at least we can get answers about the PSU circuit :-)

Kind regards
Dennis

[Dennis]

Hi guys ...
Why so quiet ?

Just a quick post to let you all know I'm still around ... no explosions, shocks or fire yet !
The test PSU is still working...
I got busy with real work suddenly and haven't had a chance to experiment more :-(

Will definitely update on the weekend !

Kind regards

Dennis

[boroko]

In case some of you didn't see this in another thread.....
www.picbasic.co.uk/forum/showthread.php?t=2736

any news on the code from Kamikaze47, seems to have disappeared.

You are right. Last seen, June 2006.

You expect to see people disappear from threads labeled:
Interfacing AC power lines....
...transformerless DC supply...
How to design without opto-couplers ...
How to measure high voltage while standing in a bucket of water...

But not from a thread labeled, “AT/PS2 Keyboard - PIC Interface?” ?

Then again we have to consider his user name!
Kamikaze47 where are you??

[mackrackit]

http://www.picbasic.co.uk/forum/showthread.php?t=12506
???

[Pic_User]

You are right. Last seen, June 2006.

You expect to see people disappear from threads labeled:
Interfacing AC power lines....
...transformerless DC supply...
How to design without opto-couplers ...
How to measure high voltage while standing in a bucket of water...

But not from a thread labeled, “AT/PS2 Keyboard - PIC Interface?” ?

Then again we have to consider his user name!
Kamikaze47 where are you??

Bo quoted from the past: 30th March 2007, 14:10, not currently.
Kamikaze47 has been back many times since the original posting.
See also Melanie’s hilarious post (standing in a bucket of water) #33 two below this quote!
http://www.picbasic.co.uk/forum/show...0&postcount=33
-Adam-