Siren, 12vdc, and sensor

Thread Starter

Wayne_2

Joined Jun 30, 2011
13
Hard wired 12vdc powered circuit. with siren and PIR Unit, OR any other idea that is better !
( I've heard pir's are temp. change sensitive, over the year for me,they are 35° to 90°F )
What should I be looking to protect, circuit wise?
this is what I've found as of today, and my sketch so far.
22ga for pir unit
18ga suggested for 12vdc

And ideas for me or sample picture, or link that can keep it simple (better for me .

Thank you for any help.
 

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ericgibbs

Joined Jan 29, 2010
18,766
hi,
I use these, they are low cost, designed for indoor use.
The sensitivity and On time can be adjusted, they work from 5vdc thru 20vdc and give a high out when PIR is detected.
The Vout can drive a transistor, which in turn can control a 12vdc siren.
There is a regulator on the board. The 'OUT' pin has a 1000 Ohm resistor in series and a 3.3V output when triggered.

Using a old PC power supply would be a very power inefficient method.

http://www.amazon.co.uk/Pyroelectri.../dp/B008AESDSY/ref=pd_cp_ce_0#customerReviews
 

Thread Starter

Wayne_2

Joined Jun 30, 2011
13
1. I guess I will buy a 12vdc power supply, I had a feeling old pc p/s would not be the right way to do it.
Would always prefer to be as energy efficient as possible!
2. looking at water level indicator and siren thread. http://forum.allaboutcircuits.com/threads/water-level-indicator-and-siren.58301/
A. I would use a transistor as a switch to the 12v siren?
B. ?? Ohm resistor for circuit protection?

Appreciate the link, looked at and will order it.

Thank you! additional help or suggestions are appreciated as this stuff is very new to me as this post shows.
 

ericgibbs

Joined Jan 29, 2010
18,766
Is the PIR and siren for a security application.?
Post the details of the siren, when you decide which one you are going to use, will suggest a suitable drive transistor.
 

Thread Starter

Wayne_2

Joined Jun 30, 2011
13
Yes, security.
Siren (Ademco747) 12vdc, 400mA
Have two of these, which I plan to mount in two separate areas.
a.) approx. <75 feet, b) <100 feet, plan to use 18ga wire.

Hope to add 2 strobes in the future.

As for p/s found a few:
Power Supply Regulated 3-12 VDC 2A 6-Way 120-536:
12VDC 10A 120W Universal Switching Power Supply Adapter Driver
120W Din Rail Mounted 12VDC 10A Output Power supply
12V-30A - DC Power Supply - 12V30A 360W

Thank you, for your help.
 

Reloadron

Joined Jan 15, 2015
7,501
Based on this:
Siren (Ademco747) 12vdc, 400mA
Have two of these, which I plan to mount in two separate areas.
a.) approx. <75 feet, b) <100 feet, plan to use 18ga wire.
Since two will be used in separate areas I believe all you really want or need is a few simple 1 or two amp wall wart adapters.
Wall Adapter Power Supply - 12VDC 1A Available from Amazon or a dozen other retailers for a few bucks each. I do not see anything in your scheme that would require a highly regulated or high current capable 12 volt supply.

I see where Eric will be giving you info on choice of transistor.

Ron
 

Thread Starter

Wayne_2

Joined Jun 30, 2011
13
I think for now I'll give that a go. Get Started with this, then expand from there. Thank you.
I hope to hear back from Eric, yourself, or anyone else who has any thoughts.

Have ordered 5 pir's, Have 2- Siren (Ademco747) 12vdc, 400mA

Near term goals
Front
1. interior: 2 alarms, 2 strobes
middle door mag switch, as back up for 2 pir's if not tripped.

Back:
1 alarm interior, 1 exterior strobe & alarm
back door and garage door mag switchs 1ea.

Longer term goals
inner area, other 3 pir's in case of skylight entry.
hope to add swann cameras ( OR open to suggestions.

Still longer term
capture and save, maybe even add auto-dialer or cable out to alert my cell or another cell.

I've been looking at aac threads and see a lot of info to try to digest.
(ie; pir, water level sensor, andrino, npn transistor switches, etc)
Would like to keep as hard wired for now.
I just need to start and expand from there.
While I know I am asking a lot of anyone.
I hope to start simple and learn as I go.
ALL help is appreciated, thank you
( by Tue. ) will be ordering for testing, a few breadboards, cable leads, and whatever else I may need to learn.
 

ericgibbs

Joined Jan 29, 2010
18,766
hi w2.
Look at this option, it uses a NMOSFET to drive the Siren.
You could use a transistor/12v relay, with a parallel protection diode instead of the FET, to drive the siren.

After power up allow about 2 to 3 minutes for the PIR unit to stabilise, initially set the Tx pot fully CCW, [ min On period] , Sx pot about 50% setting.

While setting up and installing I would recommend a mini buzzer or a LED/Resistor in place of the siren, else you will go nuts.!:rolleyes:

On my set up I have two alarm level settings.
Low, this is a low level beeper and bright LED. You may not want to alert the intruder, just catch him and hit him with a heavy object.!

High, Full siren and security flood lighting.!, hopefully scare the pants off the intruder.
A On/Off switch for the Siren part is a must.

With internal PIR's the two level, Low set up can also turn On your Hallway lights at night as you walk around.

Ask if you have a problem.

E
 

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Thread Starter

Wayne_2

Joined Jun 30, 2011
13
Good Afternoon Eric,

I had to look up some of the terms, as it has been 25+ since last project, & 40+years since I've had any elec. circuit classes.

Waiting on pir boards.

still searching for this one
FDS5674A ?

Will buy several of each, of these 3 items, to start with:
1N4148? is this good? Switching Diode DO-35 1N 4148 Signal 200mA 100V
Resistor = 1 k,
3 pin molex header
c1 is a capacitor?

any other items basic items for this project or in post #7 of mine that I should order in, to have ready?

Thank you for your helping, me get started again.
 

Thread Starter

Wayne_2

Joined Jun 30, 2011
13
Eric,

Sorry for the long delay in responding, got in all the parts, read up on parts, soldering iron, and family.
Yea, went with n mosfet, works great! I also got the 1n4148 and cap will test that as well.
How can I build in the siren/strobe circuit:
1. time delay of about 5 to maybe 15 min.
2. Stays on till turned off, If by chance I’m out and about. Hate to have everybody subject to that darn siren, hopefully someone
has called the police by that time or at least looked out a window and intruder has left!
Thank you for your help!
w :) :cool:
 

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ericgibbs

Joined Jan 29, 2010
18,766
hi Wayne,
Thats good news.
Have you experimented with the PIR, TX potentiometer settings, on the PIR PCB?
The TX pot sets the duration that the PIR is High after detecting an intruder, when the period times out the siren should go off, unless the intruder is still being detected.
[which ideally is what you want]

The pot setting is very 'coarse', try it and post the timing range you can set it for, we can then take it from there.

E

UPDATE:
Placed one of those PIR's on test, using the TX pot I could vary the ON period from a few seconds to 6 minutes.
I would say a 5 minute Siren sounding period would be enough to drive the intruder away also make you the neighbour from hell. :rolleyes:
If the intruder persists in being detected, that time will be added to the ON time of 5 minutes.
 
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Thread Starter

Wayne_2

Joined Jun 30, 2011
13
Hi Eric,
Yes, that worked. closed = 12-15 sec.,1/8 Turn = .57 min.,¼ Turn = 3.00 min.,½ Turn = 3.45 min. Yes, tested 4 times, must be made on Monday
I guess that should be okay!

Is there an easy way to wire a switch midway between the alarm and pir (so I can arm/disarm), so I don't trip it coming/going, switch now, maybe, a key pad later?
I figured the total wire length to be approx. 80 feet x 2 wire 18ga, is that over kill?

Thank you,

W
 

ericgibbs

Joined Jan 29, 2010
18,766
hi Wayne,
Is the 80ft length the wire from the remote PIR/Siren end to a local ARM switch.?
Any chance of a sketch of the proposed layout.? so that I can suggest a solution for ARMing.

Try to avoid switching the power to the PIR PCB supply, as you may have noticed the PIR output tends to be unstable for approx 1 minute after power up, this would enable the Siren.

Eric
 

Thread Starter

Wayne_2

Joined Jun 30, 2011
13
Hi Eric,

This is what I've been thinking, as always I am open to any suggestions, and guidance.
A1, wall plug is on the ceiling 13’ up
this seems as the best place for both pir & sw to be hidden from view.
note: have a Mini Siren/Strobe 12vdc, 300mA ( this will be visible at an upper window, for Notice.
Will use this in a separate, second circuit approx. same wire run.

Thank you for your help!

w
 

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ericgibbs

Joined Jan 29, 2010
18,766
hi Wayne,
Some of your cable run will have to be 3 Core or two off 2 core between some points on your wiring.

I will do a sketch, what type of cable and cores do you have.?
E
 

Thread Starter

Wayne_2

Joined Jun 30, 2011
13
Hi Eric,

Thank you for the sketch.
1.Closest is 20 AWG =.516mm., readily available 18/4 maybe 18/5
2. Signal Cable, is it ok to use 18/4, (only one cable visible up 13') might look to run in wall, but not and easy job. ?
3. I'll have to get the other parts, maybe buy some assorted of cap, res, and smaller uF in the smaller sizes.
4. On the other circuit, would the smaller Siren/Strobe 12vdc, 300mA effect any thing? Would an ultrasonic sensor HC-SR04 be better than another pir?

Your help is very appreciated!
w
 
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