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From: N Cook on 28 Mar 2007 12:37
Gives fully variable total spectrum floodlight output under remote control.
Or it would but nothing now. Full of dust and fluff in the control area and
a long term heat damaged , so presumably dramatically raised ohmage
resistor.
The bands are not discoloured , I think, reading 100 ohm , 5 percent and 1W
size. Currently reading 47K, but scraping back the end thirds of the metal
oxide spirals , the outer section thirds to each end are about 500 ohm each.

This resistor connects mains live to in-series opto-coupler, then small 3W
mains transformer primary (supplying just a 7805 for the microcontroller)
then neutral.
The opto is 4 pin P620 , presumably Toshiba TLP620 , current going through
back to back LED of 50mA rating with transistor receiver.

For the UK a 3W transformer would take about 12mA so 1.2V dropped across 100
ohm, does that seem about right ? presumably uprating to 2Watt, 100R. The
LED side of the opto seems ok at 1V diode drop either way.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/




From: N Cook on 29 Mar 2007 12:07
N Cook <diverse8(a)gazeta.pl> wrote in message
news:eue5kn$4m5$1(a)inews.gazeta.pl...
> Gives fully variable total spectrum floodlight output under remote
control.
> Or it would but nothing now. Full of dust and fluff in the control area
and
> a long term heat damaged , so presumably dramatically raised ohmage
> resistor.
> The bands are not discoloured , I think, reading 100 ohm , 5 percent and
1W
> size. Currently reading 47K, but scraping back the end thirds of the metal
> oxide spirals , the outer section thirds to each end are about 500 ohm
each.
>
> This resistor connects mains live to in-series opto-coupler, then small
3W
> mains transformer primary (supplying just a 7805 for the microcontroller)
> then neutral.
> The opto is 4 pin P620 , presumably Toshiba TLP620 , current going through
> back to back LED of 50mA rating with transistor receiver.
>
> For the UK a 3W transformer would take about 12mA so 1.2V dropped across
100
> ohm, does that seem about right ? presumably uprating to 2Watt, 100R. The
> LED side of the opto seems ok at 1V diode drop either way.
>
>
> --
> Diverse Devices, Southampton, England
> electronic hints and repair briefs , schematics/manuals list on
> http://home.graffiti.net/diverse:graffiti.net/
>
>
>
>

According to www.njd.co.uk the schematic was available via email request.
Nothing received so far though, so I will suck it and see.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/


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