I hope I'm not to far off posting this question on this forum. Some
years ago (10) we purchased 4 or 5 simple photovoltaic light switches
( I think they were made by First Alert). We're down to two
functioning now, and I cannot find these or anything near to them
anywhere (that I've looked!). They were simple plug in the wall then
plug your fixutre in and it cycled with day. My wife and I swear
First Alert took these off the market because they worked all to
well. Now all we see is digital timers etc etc. Anybody have any
leads and these simple devices?

On Mar 23, 7:17 pm, wrote:
I hope I'm not to far off posting this question on this forum. Some
years ago (10) we purchased 4 or 5 simple photovoltaic light switches
( I think they were made by First Alert). We're down to two
functioning now, and I cannot find these or anything near to them
anywhere (that I've looked!). They were simple plug in the wall then
plug your fixutre in and it cycled with day. My wife and I swear
First Alert took these off the market because they worked all to
well. Now all we see is digital timers etc etc. Anybody have any
leads and these simple devices?

I have not seen anything like that. I have see outside style porch
lights that have this feature though. Maybe they figured there's more
profit to be made in selling you an entire fixture.

wrote:

I hope I'm not to far off posting this question on this forum. Some
years ago (10) we purchased 4 or 5 simple photovoltaic light switches
( I think they were made by First Alert). We're down to two
functioning now, and I cannot find these or anything near to them
anywhere (that I've looked!). They were simple plug in the wall then
plug your fixutre in and it cycled with day. My wife and I swear
First Alert took these off the market because they worked all to
well. Now all we see is digital timers etc etc. Anybody have any
leads and these simple devices?

I looked for Intermatic because it is the only brand name I am familiar
with. They make what you describe.

http://intermatic.com/Default.asp?ac...d=58&sid=1 07

wrote:
I hope I'm not to far off posting this question on this forum. Some
years ago (10) we purchased 4 or 5 simple photovoltaic light switches
( I think they were made by First Alert). We're down to two
functioning now, and I cannot find these or anything near to them
anywhere (that I've looked!). They were simple plug in the wall then
plug your fixutre in and it cycled with day. My wife and I swear
First Alert took these off the market because they worked all to
well. Now all we see is digital timers etc etc. Anybody have any
leads and these simple devices?

check this out .. .. ..


http://x10.com/promotions/sd533_ed_lightson.html

Norminn wrote:
wrote:

I hope I'm not to far off posting this question on this forum. Some
years ago (10) we purchased 4 or 5 simple photovoltaic light switches
( I think they were made by First Alert). We're down to two
functioning now, and I cannot find these or anything near to them
anywhere (that I've looked!). They were simple plug in the wall then
plug your fixutre in and it cycled with day. My wife and I swear
First Alert took these off the market because they worked all to
well. Now all we see is digital timers etc etc. Anybody have any
leads and these simple devices?

I looked for Intermatic because it is the only brand name I am familiar
with. They make what you describe.

http://intermatic.com/Default.asp?ac...d=58&sid=1 07

Does this have any desirable hysteresis? Their K4123C control cycles 1200
watts of HIDs with a 2-minute period with about 6 footcandles of daylight,
esp if some of the light controlled reflects back into the sensor. I'm
thinking of adding a 1K resistor in series with the white wire and 39K
from there to the red wire to stop the cycling, which wears out the HIDs.

Nick

On 24 Mar 2007 01:25:31 -0500, wrote:

Norminn wrote:
wrote:

I hope I'm not to far off posting this question on this forum. Some
years ago (10) we purchased 4 or 5 simple photovoltaic light switches
( I think they were made by First Alert). We're down to two
functioning now, and I cannot find these or anything near to them
anywhere (that I've looked!). They were simple plug in the wall then
plug your fixutre in and it cycled with day. My wife and I swear
First Alert took these off the market because they worked all to
well. Now all we see is digital timers etc etc. Anybody have any
leads and these simple devices?

I looked for Intermatic because it is the only brand name I am familiar
with. They make what you describe.

http://intermatic.com/Default.asp?ac...d=58&sid=1 07

Does this have any desirable hysteresis? Their K4123C control cycles 1200
watts of HIDs with a 2-minute period with about 6 footcandles of daylight,
esp if some of the light controlled reflects back into the sensor. I'm
thinking of adding a 1K resistor in series with the white wire and 39K
from there to the red wire to stop the cycling, which wears out the HIDs.

Nick

I've had sensor nite lites and know there are periods of the morning
and evening that confuse the sensor. So while in there, add a 20
minute timer and you will eliminate all the triggers but the first
one.

http://www.homeclick.com/showpage.asp?itemid=165581
check this out .. .. ..


http://x10.com/promotions/sd533_ed_lightson.html

If you don't have your heart set on a photocell, you can also find an
astronomic digital timer to do the job. You set the time and what
part of the country you are in (there are different zones according to
the amount of sunlight during the day). Then forget about it.

I have one and every few years I have to change the battery and reset
the clock, in case it drifts. Other then that, no maintenance or
attention is required. See the link below.

http://www.homeclick.com/showpage.asp?itemid=165581

Deke wrote:

http://intermatic.com/Default.asp?ac...d=58&sid=1 07

Does this have any desirable hysteresis? Their K4123C control cycles 1200
watts of HIDs with a 2-minute period with about 6 footcandles of daylight,
esp if some of the light controlled reflects back into the sensor. I'm
thinking of adding a 1K resistor in series with the white wire and 39K
from there to the red wire to stop the cycling, which wears out the HIDs.

I've had sensor nite lites and know there are periods of the morning
and evening that confuse the sensor. So while in there, add a 20
minute timer and you will eliminate all the triggers but the first one.

Making a minimum 20-minute on-time seems to require more stuff.

I'd like to try 2 resistors first, like this, viewed in a fixed font:

normally-closed thermal relay
-------------------
| / relay o
| / heater |
|---www--- |
| Rd | | Intermatic K4123C
| | |
| | |
| photo --- | The photoconductor has a high dark
| cond. | ~ | | resistance, about 4K ohms at 6 FC.
| --- |
. . . .|. . . . .|. . . . |. . . . .
V Blk | | |Wht |Red
--------- Io| | |
Ic| | |
v | Rf | -----
|---www-------| HID |---
Vs| ----- |
| new |
| resistors |
| w |
Is| w Rs |
| w |
v | |
| |
neutral | |
-------------------------------------------

20 RD=42000!'daylight threshold resistance (ohms)
30 RS=3300'series resistance (ohms)
40 RF=330000!'feedback resistance (ohms)
50 V=277'voltage (volts)
60 IO=V/(RD+RF*RS/(RF+RS))'open-relay current (A)
70 ICS=V/(RS+RF*RD/(RF+RD))'closed-relay series current (A)
80 VCS=ICS*RS'closed-relay series voltage (V)
90 IC=(V-VCS)/RD'closed-relay current (A)
100 HYST=100*(1-(IC/IO)^2)'hysteresis (%)
120 SPOWER=ICS^2*RS'closed-relay series resistor power (W)
130 IRF=(V-VCS)/RF'closed-relay feedback resistor current (A)
140 FPOWER=IRF^2*RF'closed-relay feedback resistor power (W)
150 PRINT RS,RF,HYST,SPOWER,FPOWER

Rs ohms Rf ohms Hyst % Rs watts Rf watts

3300 330000 1.970381 .1539285 .1962148

Nick