I have a light out back of my house on a detached garage that lights up the
parking area. I would like to run it off of a mechanical timer so it goes on
at 5 p.m. and off at 10 p.m. I would also like to put a photocell on the
light so that if it isn't dark at 5 p.m. the light won't come on. Now, I
would also like to put a motion detector on the light so that after 10 p.m.
when the timer shuts off the light will come back on in case I get home
after 10 or someone trying to get in my garage would set it off.

If I feed the light from two different sources (same circuit) one through
the timer and photocell and one through the motion detector, would I achieve
my goal? Will there be a problem with each source backfeeding through the
other. I can't imagine the mechanical timer will be bothered by the load
side being hot but I'm not so sure about the photocell or the motion
detector. Could I (should I) put diodes in to keep them from backfeeding
each other? I won't be putting more than a 100-watt bulb in the fixture.

Thanks for any help,
Dave

"Dave Miller" wrote in message
...
I have a light out back of my house on a detached garage that lights up the
parking area. I would like to run it off of a mechanical timer so it goes
on
at 5 p.m. and off at 10 p.m. I would also like to put a photocell on the
light so that if it isn't dark at 5 p.m. the light won't come on. Now, I
would also like to put a motion detector on the light so that after 10
p.m.
when the timer shuts off the light will come back on in case I get home
after 10 or someone trying to get in my garage would set it off.

If I feed the light from two different sources (same circuit) one through
the timer and photocell and one through the motion detector, would I
achieve
my goal?

You do NOT want to feed through two sources. You need to have a switchable
relay to switch from one downfeed circuit to another with the motion sensor.
The motion sensor will also have a photocell. so you want to switch to that
at 10) PM to 5:00 PM

alternative plan: take a look at the seasonal lighting department for
outdoor photocell with selectable dial for desired hours such as used
for christmas lighting.
separately pick out that motion light with photocell. that way with 2
bulbs you won't go crazy when one of the control units goes crazy. and
with them burning out separately you're less likely to wind up in the
dark.

those diodes block AC and pass DC, not what you're looking to do on
this.

Edwin Pawlowski wrote:

You do NOT want to feed through two sources. You need to have a switchable
relay to switch from one downfeed circuit to another with the motion
sensor.
The motion sensor will also have a photocell. so you want to switch to
that
at 10) PM to 5:00 PM



Thanks for the reply. Can you educate me? What problems am I creating? I can
feed the relay through two sources? I don't suppose you could point me to a
relay on line that would work?
I don't suppose they make a double pole timer switch that would complete one
circuit while disconnecting the other and vice versa?

Thanks again,
Dave

I believe you are making the circuit too complicated. The power from
the motion detector would override the photocell/timeclock and your
light would work off of your motion sensor.

I would recommend just using the motion sensor. Most motion sensors
already include a photocell, so your light wouldn't turn on in the
daylight.

By using just the motion sensor, you will save money on your
electricity bill, because the light would only be on when it detected
motion and not for the 5 hour period each night. You would save more
money from not having to purchase a timeclock (approx. $50.00) and
another photocell (approx. $15.00). The circuit will also be less
complicated and have less things to go wrong.

Good luck and be safe,

Wayne
www.gilchrist-electric.com

I believe you are making the circuit too complicated. The power from
the motion detector would override the photocell/timeclock and your
light would work off of your motion sensor.

I would recommend just using the motion sensor. Most motion sensors
already include a photocell, so your light wouldn't turn on in the
daylight.

By using just the motion sensor, you will save money on your
electricity bill, because the light would only be on when it detected
motion and not for the 5 hour period each night. You would save more
money from not having to purchase a timeclock (approx. $50.00) and
another photocell (approx. $15.00). The circuit will also be less
complicated and have less things to go wrong.

Good luck and be safe,

Wayne
www.gilchrist-electric.com

Nothing wrong with your circuit at all, except as Wayne said, it's
unnecessarily complicated



"gilchrist-electric" wrote in message
ups.com...
I believe you are making the circuit too complicated. The power from
the motion detector would override the photocell/timeclock and your
light would work off of your motion sensor.

I would recommend just using the motion sensor. Most motion sensors
already include a photocell, so your light wouldn't turn on in the
daylight.

By using just the motion sensor, you will save money on your
electricity bill, because the light would only be on when it detected
motion and not for the 5 hour period each night. You would save more
money from not having to purchase a timeclock (approx. $50.00) and
another photocell (approx. $15.00). The circuit will also be less
complicated and have less things to go wrong.

Good luck and be safe,

Wayne
www.gilchrist-electric.com

On 25 Nov 2005 08:55:35 -0800, "gilchrist-electric"
wrote:

I believe you are making the circuit too complicated. The power from
the motion detector would override the photocell/timeclock and your
light would work off of your motion sensor.

I would recommend just using the motion sensor. Most motion sensors
already include a photocell, so your light wouldn't turn on in the
daylight.

By using just the motion sensor, you will save money on your
electricity bill, because the light would only be on when it detected
motion and not for the 5 hour period each night. You would save more
money from not having to purchase a timeclock (approx. $50.00) and
another photocell (approx. $15.00). The circuit will also be less
complicated and have less things to go wrong.

Good luck and be safe,


Use the timer to drive the little windmill in the front yard,
and that will set off the motion detector....

Check out the ready made motion detector/photocell units available at
places like HD. They have ones that are sold seperately from the
lights and include a photocell and motion detector all in one unit.
They can be set to give you 2/4/6 hours of illumination after sunset
and during that time you can have the lights on at 1/4 power if you
want. During the time they are at 1/4 power, or after they go out,
they will come on at full power if motion is detected. You can also
set how long you want them to stay on when motion is detected.

wrote:
Check out the ready made motion detector/photocell units available at
places like HD. They have ones that are sold seperately from the
lights and include a photocell and motion detector all in one unit.
They can be set to give you 2/4/6 hours of illumination after sunset
and during that time you can have the lights on at 1/4 power if you
want. During the time they are at 1/4 power, or after they go out,
they will come on at full power if motion is detected. You can also
set how long you want them to stay on when motion is detected.

This sounds like it may do the trick. I knew they had separate motion
detectors but I didn't know they would give you 2/4/6 hours of illumination
after sunset and then switch to motion detecting. I'll go take a look.

Thanks,
Dave

RBM wrote:
Nothing wrong with your circuit at all, except as Wayne said, it's
unnecessarily complicated

Thanks for the info. I realize this may sound foolish but I like the idea of
having the light on a few hours each evening. Kind of a "We'll leave a light
on for ya" up until 10 p.m. not a "Who goes there?" light that comes on when
it catches someone approaching. Complicated yes, but unnecessarily
complicated, maybe. Would it work to achieve my goal of having the light on
a few hours then just on when someone/something trips it.

Thanks,
Dave

Yes it would!!!



"Dave Miller" wrote in message
...

RBM wrote:
Nothing wrong with your circuit at all, except as Wayne said, it's
unnecessarily complicated

Thanks for the info. I realize this may sound foolish but I like the idea
of
having the light on a few hours each evening. Kind of a "We'll leave a
light
on for ya" up until 10 p.m. not a "Who goes there?" light that comes on
when
it catches someone approaching. Complicated yes, but unnecessarily
complicated, maybe. Would it work to achieve my goal of having the light
on
a few hours then just on when someone/something trips it.

Thanks,
Dave

Dave Miller wrote:
I have a light out back of my house on a detached garage that lights
up the parking area. I would like to run it off of a mechanical timer
so it goes on at 5 p.m. and off at 10 p.m. I would also like to put a
photocell on the light so that if it isn't dark at 5 p.m. the light
won't come on. Now, I would also like to put a motion detector on the
light so that after 10 p.m. when the timer shuts off the light will
come back on in case I get home after 10 or someone trying to get in
my garage would set it off.

If I feed the light from two different sources (same circuit) one
through the timer and photocell and one through the motion detector,
would I achieve my goal? Will there be a problem with each source
backfeeding through the other. I can't imagine the mechanical timer
will be bothered by the load side being hot but I'm not so sure about
the photocell or the motion detector. Could I (should I) put diodes
in to keep them from backfeeding each other? I won't be putting more
than a 100-watt bulb in the fixture.

Thanks for any help,
Dave

Too much work. Check out www.smarthome.com or other supplies and find
one fixture that will do it all for you. Don't limit yourself to mechanical
timers, they tend to be less reliable anyway.

--
Joseph Meehan

Dia duit

It seems to be it would be a lot easier and cheaper to install 2
lights. You can buy one with a motion detector at home depot for about
10 to 15 dollars. Put that on one corner of the garage covering the
areayou need covered. The other regular light you could just hook up to
a timer. Adjust the timer as needed for the season....5pm winter...8 pm
summer.

Just my thoughts
Pat

I don't know about that, but I think that with X-10 stuff you could do
it:

An X-10 motion detector set to go on at dusk and off at dawn. Then
their Home Control with a macro set to turn the lights off at 10 PM.
Since it's a motion detector, it would still light up if it detects
motion at night.

You'd need an X-10 motion detector ($50) and a mini timer ($30) or some
sort of Home Control Kit. But they always have some sort of deal on
their website that eventually would make this cheaper (for example, I
recently got two motion detector lights for $50). You could also get a
regular light fixture (around $20 or less at Home Depot), two socket
rockets from X-10, and an outdoor motion detector, plus a home control
kit. There are a few ways to solve this problem.

Shaun Eli
www.BrainChampagne.com
Brain Champagne: Clever Comedy for the Smarter Audience (sm)

My head is spinning. I think you can keep the light off using a timer
but to have two different ways (timer and motion) seems "interesting".
You may need to do two lights.