Relay system for Halloween decorations

Hi...I wonder if this would be an easy project.

I want to have a pressure switch under a doormat.
When someone steps on the switch, I want a strobe light and cassette
player to turn on, and run for approximately 30-60 seconds.

Is this easily accomplished?
I thought about a motion detector with X10 receiver and appliance
module, but that would be over $100!

 

[Adam Aglionby]

<Mitch@hotmail.com> wrote in message
news:3h33ov4i4d2pk7481sut9njclpmam027e0@4ax.com...

Hi...I wonder if this would be an easy project.

I want to have a pressure switch under a doormat.
When someone steps on the switch, I want a strobe light and cassette
player to turn on, and run for approximately 30-60 seconds.

Is this easily accomplished?
I thought about a motion detector with X10 receiver and appliance
module, but that would be over $100!

Think more cheap PIR outdoor floodlight, the motion sensing ones, remove
floodlight and use pir sensor and relay.
Good place to look around:

http://wolfstone.halloweenhost.com/HalloweenTech/MainHalloweenTech.html

Adam

 

Think more cheap PIR outdoor floodlight

Thanks....I'm still on the lookout for a floodlight that would give me
control over timing. I looked at the inexpensive Regent units today,
and the minimum time before shutting off is 4 minutes.

Regartding that subject: can I simply screw one of those
light-socket-power receptacle adapters, or do I need to modify the
unit?

 

[the Wiz]

Mitch@hotmail.com wrote:

Think more cheap PIR outdoor floodlight

Thanks....I'm still on the lookout for a floodlight that would give me
control over timing. I looked at the inexpensive Regent units today,
and the minimum time before shutting off is 4 minutes.

Regartding that subject: can I simply screw one of those
light-socket-power receptacle adapters, or do I need to modify the
unit?

As long as the device you're powering is within the current range of the
controller, you're OK. If the floodlight unit is rated at 300 watts (two 150
watt bulbs), then you can safely control about a 2 amp load.

More about me: http://www.jecarter.com/
VB3/VB6/NSBasic Palm/C/PowerBasic source code: http://www.jecarter.com/programs.html
Drivers for Pablo graphics tablet and JamCam cameras: http://home.earthlink.net/~mwbt/
johnecarter at@at mindspring dot.dot com. Fix the obvious to reply by email.

 

[Terry Pinnell]

Mitch@hotmail.com wrote:

Hi...I wonder if this would be an easy project.

I want to have a pressure switch under a doormat.
When someone steps on the switch, I want a strobe light and cassette
player to turn on, and run for approximately 30-60 seconds.

Is this easily accomplished?
I thought about a motion detector with X10 receiver and appliance
module, but that would be over $100!

It should be simple and cheap to build, assuming you have the basic
skills.

You would trigger a 555 monostable with a -ve going input pulse. An
improvised microswitch under the mat could be used, with appropriate
connection to the DC supply to ensure correct polarity. Or, more
expensive, a mat with inbuilt sensor, as used in commercial burglar
alarm kits. The mono's output would drive an appropriate relay
directly, assuming standard 555 with 200mA capability (100mA for the
CMOS version). Mains to the strobe light and cassette player would be
switched by the relay.

If your trigger was a +ve going pulse, then you might use a circuit
such as
http://www.terrypin.dial.pipex.com/Images/555MonoEdge.gif

You would of course need to change the RC values. In your case, for C
you could use say a 68 uF electrolytic, and for R you could
substitute a series combination of a fixed 220k with a 1M pot, to
easily accommodate the range you specified. Or use any other Rs and Cs
at hand, keeping the RC product constant.

Alternatively (one of many) you could use the neat idea already
suggested of a PIR, but add the 555 circuit to give you the variable
timing. One approach would be to arrange for the mat to switch DC
power to the alarm circuit, simultaneously triggering the alarm. A
circuit using that approach is suggested at
http://www.terrypin.dial.pipex.com/Images/555MonoByPU.gif

Have you decided what you want to do about repetitive triggering?

Please post back if the above is pitched at the wrong level.

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

I found a cheap Regent PIR.
It has 3 wires: black, white, and red.

I'm unsure which of the three wires is unused, assuming I'm using a
2-prong extension cord (cut in half).

 

[Adam Aglionby]

<Mitch@hotmail.com> wrote in message
news:bdjgovkq3vb81j25m5v831198n5hn6jdep@4ax.com...

I found a cheap Regent PIR.
It has 3 wires: black, white, and red.

I'm unsure which of the three wires is unused, assuming I'm using a
2-prong extension cord (cut in half).

Im in the UK and you realy want someone leaning over your shoulder to tell
you exactly or the instructions must provide a pointer...
But general scheme will be common neutral, live supply and switched live
out, in Europe earth is common and three wire extensions.

Adam

 

[JeffM]

You've been watching too many movies
where the bomb guy on the other end of a phone line says,
"Cut the blue wire".

The color coding might be white=neutral, black=hot, red=switched
--then again , it may not.
You'll have to take it apart to tell.

Something else that no one has mentioned
is that a solid-state switch (triac)
generally has a minimum load requirement
(has to pull at least X current, relative to full spec).

 

[Terry Pinnell]

Terry Pinnell <terrypinDELETE@dial.pipexTHIS.com> wrote:

Mitch@hotmail.com wrote:

Hi...I wonder if this would be an easy project.

I want to have a pressure switch under a doormat.
When someone steps on the switch, I want a strobe light and cassette
player to turn on, and run for approximately 30-60 seconds.

Is this easily accomplished?
I thought about a motion detector with X10 receiver and appliance
module, but that would be over $100!

It should be simple and cheap to build, assuming you have the basic
skills.

You would trigger a 555 monostable with a -ve going input pulse. An
improvised microswitch under the mat could be used, with appropriate
connection to the DC supply to ensure correct polarity. Or, more
expensive, a mat with inbuilt sensor, as used in commercial burglar
alarm kits. The mono's output would drive an appropriate relay
directly, assuming standard 555 with 200mA capability (100mA for the
CMOS version). Mains to the strobe light and cassette player would be
switched by the relay.

If your trigger was a +ve going pulse, then you might use a circuit
such as
http://www.terrypin.dial.pipex.com/Images/555MonoEdge.gif

You would of course need to change the RC values. In your case, for C
you could use say a 68 uF electrolytic, and for R you could
substitute a series combination of a fixed 220k with a 1M pot, to
easily accommodate the range you specified. Or use any other Rs and Cs
at hand, keeping the RC product constant.

Alternatively (one of many) you could use the neat idea already
suggested of a PIR, but add the 555 circuit to give you the variable
timing. One approach would be to arrange for the mat to switch DC
power to the alarm circuit, simultaneously triggering the alarm. A
circuit using that approach is suggested at
http://www.terrypin.dial.pipex.com/Images/555MonoByPU.gif

Have you decided what you want to do about repetitive triggering?

Please post back if the above is pitched at the wrong level.

Guess I'll assume it was then.

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Adam Aglionby]

"JeffM" <jeffm_@email.com> wrote in message
news:f8b945bc.0310111913.1e3d9630@posting.google.com...

You've been watching too many movies
where the bomb guy on the other end of a phone line says,
"Cut the blue wire".

The color coding might be white=neutral, black=hot, red=switched
--then again , it may not.
You'll have to take it apart to tell.

Was trying to avoid allocating colours to connections, the instructions with
the unit should help here...

Something else that no one has mentioned
is that a solid-state switch (triac)
generally has a minimum load requirement
(has to pull at least X current, relative to full spec).

Most of the PIR floods I`ve encountered use a miniature relay, outside
chance of welding it if relay operates jsut as strobe is firing, but very
outside chance, if its a triac, use a ghost load out of sight, like a 40 w
lamp.

Adam