RS 49-425 Sensor

Archilochus

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Hi all,
After reading about everyones success with the RS 49-425 sensor, I thought I'd dig up the one I had laying about and use it in a trail-cam with a spare Infinity Jr.   I've been building my own sensors, but I figured why let the thing sit there and rot?

Anyway... Thought I'd share this info on it - probably everyone knows this stuff already, but it's all new to me.

For some reason the senor uses about 20% less power in the "alarm" mode (100uA in "alarm" and 125uA in chime)

If you use the "chime-off-alarm" switch for turning the sensor on and off, the sensor continues to use just as much power even in the "off" position as when switched to "alarm".  Remove the batt when not using the sensor to keep it from draining the batt (only need to do this if you use the "chime-off-alarm" switch to switch the sensor on and off).

Pin #2 of the "big IC" on the circuit board gives a 5 volt output.  If you use the speaker wires to drive your relay you'll need to use a 9 volt relay, as the speaker is driven with raw battery voltage.

The voltage regulator used in my 3 year old sensor is an obsolete Holtek IC.  It can tolerate input voltages from 6 volts absolute minimum to 12 volts maximum - so you can use a fairly wide range of batteries to power the sensor.

I slapped together a quick timer board for this sensor.  If interested, take a look at < http://www.geocities.com/archilochus57 >  at the bottom of the page.
>>>>>>>>>>>>>

A couple questions for users of this sensor........
Does your sensor tend to start off very sensitive when first switched on - then level off to a lower sensitivity after about 10 minutes?

How much of the lens do you cover to reduce the field of view so that the subject is in the picture?

Anyone used this sensor at high / low temps? - How does it behave under those conditions?

Archilochus
 



NC Bowhunter

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Arch-

I used the RS sensor in only camera so far, and have had great success with it.  I wired mine off of one of the pins in the small IC chip (I don't remember which one) to trip the relay for 30 seconds using the alarm mode.  This was a very easy way to get a 30 second delay.  I covered part of the fresnel lens leaving about two of those vertical strips showing which gave me a good field of view.  I never noticed any change in sensitivity after turning it on, but it could be possible.

That timer you built looks very nice and does fit in there perfectly.  I don't think I could manage to build one, but maybe some day I'll try.  Exactly what does that timer do?
 

Tinhorn

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Archy

That's some "Slap"  ha ha.  I'm glad you posted the schematic, I've been thinking about the Opto-Isolators you mentioned and may build this timer for the next camera.  I see you pointed out which Cam Lead goes to the Collector,  I had the leads reversed on one of my timers that I used an NPN on.  It worked till the batt's got low, switching them fixed the problem tho.

Somebody posted the schemtic for the RS sensor awhile back if you didn't notice, I saved it if you need it.

I've been meaning to ask about when you built all those cameras (110 I think)   did you contract that out or have a crew do it?  Just curious......
Tinhorn
 

Archilochus

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Hi Tinhorn, NC Bowhunter,

NC...... The timer circuit generates an adjustable time delay between photos so one animal does not take a bunch of pics in a row (adjustable from about 15 sec to 1.6 min)    It also generates a 3 second shutter timer which is long enough to trigger most any cam.

Tinhorn....... meant to note this on the schematic page.....The emitter/collector wiring as shown works for the Infinity Jr, the Owl series, the Canon Elph and probably many other cams.  Some cams need the wires to be switched - the Fuji AF 60 for example.  Some cams work either way.
I have a copy of the RS sensor schematic on my computer somewhere - just need to try and remember what I named it.
All those Infinity Jr cams were made for a research project studying forest bird nest predators.  At the time  (1992-93) I was just starting to fool around with automatic cameras. One of the guys working on the project asked if I would be interested in building their cams.  I said.. hey, sure, that sounds great! -  and soon regretted it!  I was sort of the "on-call" camera guy.  I had to modify the cams, build and camo paint all the boxes, rig up various triggers and fix the cams that stopped working or got smashed by bears /chewed up by porcupines.  I even did a fair amount of the set-up and take down work.  Didn't charge nearly enough.
It's much more pleasant to build cameras for your own use.  Did learn a lot from the experience though.  What I need to do now is get a good negative scanner so I can scan the big pile of negatives I have.  The project leaders kept all the prints.

Archilochus
 

spectr17

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Thanks for the updates Archilochus, I'll add your info to the Radio Shack 49-425 webpage.

I bet you got some dandy pics in that pile of negatives.

I don't cover any of the lens off, the lens is flat and moutned flush with the ammio can. Temps have been mild here so far but this summer we'll get up to 110 a few days so that should let me know how the hot side works.

I'll pay more attention to the sensitivity on startup next time.
 

Richard Webb

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Arch-

Thanks for all the help with the 49-425.  My project is just about ready for some of your ideas.  (I have a spot 1" X 1-1/2" X 1/2" high reserved)  By the way, Inside the PIR battery compartment on the back wall it says:  "After install/replace the battery allow 60 seconds for warm-up in Off Position."  That is why I'm not planning on using an ON/OFF switch for the PIR.  Jon came up with a pretty good ideal by wedging everything into the Radio Shack 4 X 6 X 2 Plastic Box. Later this assembly can be mounted inside a steel box if more security is needed.
 

Archilochus

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Hi Richard,
The space you have should be plenty. That's odd about the note inside the batt compartment - my older sensor does not have that note.  I wonder if the circuit has changed since I bought my sensor 3 years ago?  It looks the same when compared to the pics on Jesses web-page.

Archilochus
 

Richard Webb

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Arch-

Do I need to cut out a hole for the Owl PF Light-Meter Sensor?  I still don't understand what happens when there is a jumper between #5 & #6?


Ammended:  Most of us don't have the slightest idea about bread boarding a circuit.  If you would be kind enough to post a pic of both the front & back side of your 49-425 timer/opto board it would be very helpful.  I like your Webpages.  



(Edited by Richard Webb at 2:30 pm on June 2, 2001)
 

Archilochus

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Hi Richard,
The Owl PF has 3 sensors (well....2 sensors and 1 emitter).  The one under the lens is the auto-focus sensor.  The large one to the left of the viewfinder is the AF emitter.  The small one above the AF emitter is the  light meter / flash sensor.  If you block the light meter sensor the flash will be active all the time (if the cam is in "auto" mode) as the cam will think it is dark out.  I don't know if this sensor has any effect on the cameras exposure settings - I'm guessing it does.  I always make holes for all the sensors because when I tested my Fuji AF 60's there was a noticeable loss of picture quality when the AF sensors were covered.  I've not tested the Owls with the AF sensors covered, but others on this forum have said covering them makes no difference.

Regarding the jumper between #5 & 6.... The shutter has two steps.  The 1/2 press sets the exposure values and focus settings and will lock them so you can focus on a centered subject then press and hold the shutter halfway while you compose your picture.  After your picture is composed, you press the shutter fully down and a picture is taken.  You can also just press the shutter fully in one shot and the cam takes the pic focusing on and exposing for whatever is centered in the frame.  Either way, both the shutters "1/2 press" and "full press" contacts need to make contact with the shutters "common" contact (#4) in order for a pic to be taken.  So by jumping  #'s 5 & 6 (which are the circuit board traces for the shutter 1/2 and full press contacts) and connecting them to the common wire with your sensor relay, you have convinced the camera that the shutter has been fully pressed.

If you solder a jumper at the # 5 & 6 circuit board traces, you will lose the ability to use the focus and exposure lock that the 1/2 press shutter position offers.  If you never plan to use the cam separate from the trail cam, that's no big loss.  If you do plan to use the cam separately, you can do this:  Use a *stereo* audio jack and plug as the disconnect for the cam.  On the connector that stays with the trail camera circuitry (usually the plug or "male" half), solder a jumper between the appropriate terminals so that when the  connector halves are joined, the wires for #'s 5 & 6 are shorted together  (the female half of the connector stays with the camera itself).  When the connector is disconnected, the wires for #'s 5 & 6 in the female half of the connector are an open-circuit, letting you use all the functions of the camera.

I'll post some pics of the finished circuit board, but I'm afraid they might not be much help.  I really did a "quickie" job on this board, and it's kind of sloppy.  Due to limited space, I also used some surface-mount components which make the circuit layout less obvious.

Archilochus
 

Richard Webb

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Hi Arch-

Thanks for the help.  I noticed that the flash was working during day light hours, so I'll drill another hole for the flash sensor.  I used a 3-Conductor 3/32" Submini Stereo Phone Jack, Radio Shack #274-245. (Camera Pin #4 goes to the tip, and Camera Pins #5 & #6 go to the two shank positions.) That way, when a Two Connector Mono 3/32 Phone Plug (Radio Shack #274-289) is inserted the shank will bridge Camera Pins #5 & #6 while the tip is the Camera Common Pin #4. Then, I ran the two leads from the Mono Plug to the Reed Relay.  Don't know if I like how the 49-425 behaves?  There is something about that thing that's not consistent?  Like, out at 20 feet it's on again/off again in front of the cam, but it works best in one spot off to the left of the camera.  Oh well, it's the kids camera, so why worry about it.

Ammended:

Getting the two vertical strips of the Fresnal lens aligned is tricky.  When I took the cam out in direct sun light I could see the metal case of the sensor through the Fresnal lens.  I have it working good now at 20 feet.  Should be even better at night when there is a greater change in body tempature.


(Edited by Richard Webb at 1:39 pm on June 3, 2001)
 

Archilochus

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Hi Richard,
That's an excellent idea using the mono jack to short the wires!
>>>>
I was never really pleased with the 49-425, but I had it in my junk drawer so I figured I'd use it.  It seems to have unpredictable sensitivity - walk test it  and everything is fine - come back in an hour and it can only detect to 10 feet.  10 minutes later it's fine again.  Also seems to have some odd irregular "dead zones" when you try to use it on smaller animals (raccoon size and smaller).
This was with fresh batts and no real change in temperature conditions and before any modifications were made.

On the positive side:  Low power, smallish size, and easy to modify.

To get around the lens alignment problem, I left the circuit board and lens installed in the original housing and used some IR transmissive material for the window that the sensor 'looks' out of.  Of course you'd never fit the original sensor housing into that little RS 'hobby' box.  I used a 6 x 6 x 3.5 box from Mouser electonics
< http://www.mouser.com >   Part # 563-NBB-10240

Archilochus
 

Richard Webb

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Arch-

We have an abundance of wildlife at our local reservoir, so I'm giving the 49-425 a real life test.  That place is busy during weekends, and this will only be a Monday through Friday test.  Based on the animal tracks I seen, the people who swim up in the coves share the same beach with the wildlife that water there at night.  I walked up the ravine a ways, and tied the cam to a tree about 8 feet from a trail leading to the water.  The small 6 X 4 X 2 Radio Shack box with camo tape on it sure sticks out like a sore thumb.  Needless to say, using a larger steel transformer box is on hold until I learn more, but I can see the advantage of using a hinged door while the cam is attached to a tree.  What is the optimum range for the 49-425?  In my backyard it was pretty reliable out at 20 feet, but I shortened the distance out in the field to I catch a bob cat.  At this point I think the 49-425 is worth the extra money, but wont know for sure until I catch a small animal like a bob cat with it.  I'm pretty sure that the cool night air will make the small animal's body heat trip the RS Mini PIR.  
 

Jon Bain

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Archilochus, Richard, I am starting to get worried about the RS 49-425 form the posts I've read lately.  Now correct me were needed, but did I read that the little 5v relay will burn out before too long?  The reason I ask is because mine is wired directly from the speaker wires.  I do have the diode in there and the test light too, but is the 9v going to burn out the little relay in short order?  Also, can't a resistor or something be put in line to knock the voltage down to what the realy can take, but still be enough to trip the camera?  I've stopped work on my other camera until I get this issue resolved.  Does RS sell a comprable relay that matches the 9v output?  Any help is appreciated.  JB
 

Richard Webb

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Jon-

I have the walk light (LED) hooked to the Speaker Wires, and the Relay hooked to pin 2 of the large IC Chip.  When I checked pin 2 it was 5 volts, but I don't hae a scope to check if has a ripple.  Did you check to see how far out the 49-425 will trip the camera?  
 

Jon Bain

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I was getting maybe 20' max.  Checked it several times and and it seemed to work out to 15' to 20' and that was it.
 

Tinhorn

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RS Sensor Problems:

I don't have a RS motion sensor but in reviewing the Schematic, it looks to me like there is a rather simple way to fix the singing relay problems and prevent rapid wear of the relay.

Archy:

Maybe you can review this idea on the RS schematic with me.

I think Pin 2, of the Large IC, goes Hi when Motion is Sensed and turns on the Small IC (which I believe is an Audio IC)

If this is the case, I doubt there is any Audio on this pin, so do the following:

1.  Unsolder and lift one leg of R14 that connects to pin 2 of the small IC

2.  Solder a jumper wire on this lifted leg over to pin 4 of the Small IC (or to Pin 2 of the Large IC, they are connected)

3.  Attach the Relay Coil leads to the speaker wires

What this will do (I think!) is turn the Audio Amp Transistor into a "Relay Driver".  The signal from Pin 2 of the Large IC will drive the Audio Amplifier Transistor  (Q1?-illegable-) by going thru R14 to it's Base.

If an LED is desired, it could be connected to the Audio Transistor speaker wire as well.....

How long the relay is kept pulled in is probably dependant on the Mode the Sensor is in, either Chime or Alarm.

Like I said, I don't have a RS sensor to test this idea, but I believe the singing relay is BAD....

Tinhorn

(Edited by Tinhorn at 11:32 pm on June 4, 2001)
 

Richard Webb

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Tinhorn-

I think you are on to something here, but lets leave the shutter relay that is normally open on pin 2 of the large IC, and use the new audio amp transistor output to activate a second relay that is normally closed that will open breaking contact with the PIR sensor while a capacitor discharges for 1 minute.    
 

Archilochus

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Hi all,
Tinhorn......That idea looks like it would work great.  Pin #2 of the big IC gives a level "HI" output when motion is detected.  The small IC generates the audio as you guessed.  So driving Q1's base (or gate-it might be a MOSFET-could not find any specs for the part #) from pin 2 of the big IC will get rid of the "singing" relay.

Jon.............There's a post not too long back - something like "the little relay that couldn't"  You might want to look it up.
I think 1 of 2 things are killing the "singing" relays:
1)  The relatively high audio frequency that normally drives the speaker might be wearing out the relay - they have a life of ~100 million operations or so, but that could get used up quickly at audio frequencies.
2) The speaker is driven with the raw battery voltage - 9 volts.  If you hook up a 5 volt relay at the speaker wires thats an 80% over-voltage condition - beyond specs for many relays.  Adding a small amout of resistance in series with the coil should extend its life - I've done that in the past and the circuit is still going after 4 years of constant use.  You'll have to experiment with "R" values - keeping in mind to make sure the relay will still pull with a nearly depleted battery.

>>>>>>>>>>>
Some users have found that pin#2 of the big IC won't drive their relay properly.  This output is most likely a CMOS compatible output (a guess-no data sheet for this part).  It can most likely deliver no more than 20 - 25 mA of current.  Thats only enough for the smallest of relays, and even with a small relay that will still be an unusually large load for a logic level output - possibly leading to premature failure of the IC.  Using Tinhorns' idea would buffer the IC from the load nicely.

>>>>>>>>>>>
Richard.........You should be able to find a single "dual pole" relay with with one normally open and one normally closed pole.  Save some power and board space.  Look for "telecom" or "telcom" relays.
By the way - I posted the pics of the timer PC board top and bottom at http://www.geocities.com/archilochus57   Hope they can help out some.

I've tested the sensor itself out to about 35 feet at 68 degrees F ambient temp.  Mounted in the housing it has to "look" through some plastic, so it only reaches to about 30 feet.

Archilochus
 


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