Re: Light sensor for OFF at dusk and ON at daylight?

["Bob F" <bobnospam@xxxxxxxxx>]

Jim H wrote:
> On 10/26/2010 7:38 AM, dh@. wrote:
>> On Wed, 20 Oct 2010 23:50:17 -0400, "Petem"<petem001@xxxxxxxxx>
>> wrote:
>>
>>>
>>> "Stubby"<William.Plummer@xxxxxxxxxxxx>  a écrit dans le message de
>>> groupe de discussion :
>>> 8fd119b3-bc27-448d-b6fb-5e45c597aa16@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>>>> On Oct 17, 11:05 pm, dh@. wrote:
>>>>> I'm interested in finding a light sensor/110V outlet combination
>>>>> that turns things off at dusk an on at daylight, instead of the
>>>>> other way around as most of them do. Can anyone suggest where to
>>>>> get such a thing, or where else I can ask about it?
>>>>
>>>> You could use two light sensors in a box (with ventilation!).  The
>>>> first looks at the world while the second looks at the light on the
>>>> first sensor.
>>
>>      That idea worked great. It's probably the way I'll go with it
>>
>>> Just put a 110 volt realy at the place of the lamp connection in a
>>> simple dusk detector and use a N.C. connection on it to feed what
>>> ever you want.. if the relay is OFF (when the detector see some
>>> light) the currenty pass .. simple simple simple..
>>
>>      I'm interested in trying that but don't know an easy place to
>> get the relay, or what an N.C. connection is. I did however get
>> two light sensors like "Stubby" suggested and it seems to work
>> pretty well.
>
> parts-express.com has relays for many different voltages. A 120 volt
> relay is about $10.00. The N.C. connection is the "normally closed"
> connection. It is a closed circuit before the relay is activated. It
> opens upon activation. The opposite is the normally open connection
> which is the opposite of the normally closed.
>
> The relay is small, does not require much power (none when it is not
> activated). It doesn't put out heat, and it is easy to wire into a
> circuit. It  does seem like a better choice than the two light
> suggestion.

It does matter what you are turning on. Relays handle different amounts of
current and voltage for difeernet kinds of loads, and should be spec'ed for your
load.