LED fibre optic hack.

[Steve]

Why don't you bother to find something out about the subject before writing
such nonsense?

This is from skin-resistance=100 Ohms man ?

This circuit is dangerous - it is well above the threshold allowances of
BSEN,UL,CSA, ...... and on and on.

but is it dangerous ? The stored energy is too low, and the discharge
voltage too low to be a safety hazard. Unpleasant, but not a safety
hazard. You can get more wallop from a static discharge than this cap
gives you. 15kV, 60mJ 8-10AMPS

Steve

 

[Ian Stirling]

Most of the tatty pound shops around Glasgow had them for a while, but
they don't seem to have them at the moment. Maybe they'll come back in.

I guess I don't frequent the right sorts of shops...
(wanting to play with noncoherent fiber bundle imagers)

 

[Adam Aglionby]

Why don't you bother to find something out about the subject before writing
such nonsense?
This circuit is dangerous - it is well above the threshold allowances of
BSEN,UL,CSA, ...... and on and on.

Hope readers of sci.engr.lighting and Clive`s website are aware that coffee
is hot , wet floors are slippery and mains electricity is to be treated with
respect.

Actually have a Clive plug in light, assembled by the originator, taking my
life in my hands unplugged the stone cold after running for several weeks ,
LED light, and touched the L pin, its a sharpish nip but its not going to
ruin your whole day.

If just unplugged the LEDs themselves glow gently as they bleed the
capacitor down.Can see the thought about a bleeder resistor...

Its certainly not the most dangerous circuit on Clive`s website, but then a
certain familiarity is assumed in the reader, with mains electricity.
Anything that plugs in is potentially lethal, residual currents are not
confined to transformerless supplies , which as Clive points out are
increasingly popular even on 220/240 50 Hz . I`ve had some prime nips off
computer PSU`s , with CE,UL,TUV etc marks.

Adam

 

[Clive Mitchell]

Actually have a Clive plug in light, assembled by the originator, taking my
life in my hands unplugged the stone cold after running for several weeks ,
LED light, and touched the L pin, its a sharpish nip but its not going to
ruin your whole day.

Um, that little unit IS fitted with a 1M discharge resistor.

But if you get it out the socket at just the right point
(top-o-the-sinewave) and get your fingers on quickly enough, then you
can probably assist the discharge resistor in it's duty. You may have
to lick your fingers and remove the plug several times to achieve this.
With practice you can remove the plug and get your fingers on the pins
in less than half a second.

Of course, if it was based on a UL approved American plug it would be
much easier, since you could put your finger over the pins while it was
still plugged in.

 

[R.Lewis]

Mr Skin resistance = 100 Ohms ? Not me who needs to find out about the
subject.

Bear in mind that a human body (nominal capacitance 200pF) can store
56mJ, at 15kV and be pissed off but unharmed by nearly 10A of discharge
current from a static event. How can you contend that an isolated 300nF
can be "dangerous" is interesting. Please justify it numerically.

Proof ?

Just for a start, since you are in the UK and this is a lighting forum:
How about EN60598

I wonder why, in that standard, there is a maximum ......

 

[Adam Aglionby]

Um, that little unit IS fitted with a 1M discharge resistor.

er, was, it became a test bed and parts supply...

But if you get it out the socket at just the right point
(top-o-the-sinewave) and get your fingers on quickly enough, then you
can probably assist the discharge resistor in it's duty. You may have
to lick your fingers and remove the plug several times to achieve this.
With practice you can remove the plug and get your fingers on the pins
in less than half a second.

I wondered what the CE testing procedure was.

Of course, if it was based on a UL approved American plug it would be
much easier, since you could put your finger over the pins while it was
still plugged in.

its all safe as houses at 110V though surely

The fuse in live And neutral in a UL approved plug did make me wonder
though.
But then these people can`t tell there `R`s from. there elbow ;-)

Adam