Night light

[Fred]

I make wooden night lights and would like to install a photocell for
switching on/off. I bought a photocell, wired it up, and it worked
perfectly except for one minor detail -- the light comes on in the
morning and shuts down at night. I heard there is a small circuit that
could reverse this. Does anyone know of them and of a possible place to
order them? Thanks, Fred

 

[petrus bitbyter]

"Fred" <fpedersn@webtv.net> schreef in bericht
news:3444-42C8444A-745@storefull-3336.bay.webtv.net...

I make wooden night lights and would like to install a photocell for
switching on/off. I bought a photocell, wired it up, and it worked
perfectly except for one minor detail -- the light comes on in the
morning and shuts down at night. I heard there is a small circuit that
could reverse this. Does anyone know of them and of a possible place to
order them? Thanks, Fred

Er... *wooden* nightlight? Guess you don't use burning wood? But what type
of light do you mean? Voltage, current, DC, AC? What photocell are you
talking about? There are zillions of types out there you know. You wired it
up you say but you don't tell how. I can guess of course (and my educated
guess says you put some low voltage lamp in series with a LDR) but even then
I generate some hundreds of possibilities about the details that matter.
Even when I'd write them down - but be sure I will not - how would you find
the right one? So when you provide some more details, you'll get a much
better answer.

petrus bitbyter

 

[Baphomet]

Here's one:
http://www.mitedu.freeserve.co.uk/Circuits/Switching/nitelite.htm

"Shane Kirkman" <shanekirkman@yahoo.com.au> wrote in message
news:bihmaa$9f48a$1@ID-197890.news.uni-berlin.de...

I am after a few simple night light circuits.


Thanks Shane.

 

[Rich Grise]

"Baphomet" <fandanospam@catskill.net> wrote in message news:<vkp4c7ljmiphb3@corp.supernews.com>...

Here's one:
http://www.mitedu.freeserve.co.uk/Circuits/Switching/nitelite.htm

"Shane Kirkman" <shanekirkman@yahoo.com.au> wrote in message
news:bihmaa$9f48a$1@ID-197890.news.uni-berlin.de...
I am after a few simple night light circuits.


Thanks Shane.


I'd add some kind of hysteresis so you don't get chatter

around dusk. Maybe lift both emitters from ground, and tie
them together and to the top of a, say, 22 ohm resistor,
which goes to -supply. Then, when the second transistor
turns on, its emitter current adds to Q1's, raising the
emitter voltage, which is ampilfied by Q1, etc.

Have Fun!
Rich