View Full Version : Two Second One Shot 555 Timer For Camera
03-20-2001, 08:06 PM
I thought that I would post this schematic here for the benefit of those that may have not seen this timer on the other forums. ###This is a very simple one shot timer that provides a two second shutter trigger for game trail cameras. ###It resets the shutter after two seconds regardless of how long the PIR triggers so that the dreaded 3 minute shutoff does not occur, which is a problem with the Canon Owl cameras. ###This is but one of many timer designs that have been submitted for use in the trail cameras, but in my opinion, the most simple. ###When used with the MS20 PIR, the internal timer of the MS20 can be utilized with this 555 timer to avoid multiple pictures of the same animal. ###Sort of two birds with one stone.
Many thanks again to Tinhorn for his expertise in figuring this timer out for the rest of us.
Welby - I have a question or two about this setup. I'm thinking of trying this timer for my videocam since the Marty Timer is not working out for that. I'm using an SPDT relay to short the camera's REC/STOP contacts(the same contact turns the cam on and off). Seems the SPDT relay is switching so fast that the timer board is not sensitive enought to detect it and my camera is not turning on/off all the time. Anyways...
With the SPDT relay one contact is always closed so my question would be, will this adversely affect the one shot timer?
Basically in the NC position the relay is waiting for movement, when movement occurs the relay will go to the NO contact(closing it) and start the 2-3 sec timer(turning cam on). When the MS20 resets the MS20 relay will go back to the NC contact and start the 2-3 sec timer again(turning cam off). It will stay in the NC position and the cycle starts all over again. Do ya think it might work?
Thanks for your help and for posting the schematic's.
(Edited by gizz at 8:05 am on Mar. 22, 2001)
03-22-2001, 10:11 AM
Anybody have anything for 9V circuit........or can the same schematic be used?
03-22-2001, 12:23 PM
gizz, I'm not really sure how this ###timer would work in that application. ###I'm sorry I can't be of more help than this, but I'm still just getting a grasp on simple electronics. ###Tinhorn really helped me out a lot with this and he'd be the one to ask. ###He is really sharp on this stuff. ###Sorry.
jayber, I think this timer would work with 9V, but not sure how well.
Jayber - The basic design of this circuit is listed in my "getting started in electronics" by Forrest Mims book as having a 9 volt input. In the Timer, Op Amp, and Optoelectronic... book as having a 12V input. I can see no reason why it wouldn't work with either.
Welby - I'm just gonna build it and try it. I picked up all the parts today.
(Edited by gizz at 5:39 pm on Mar. 22, 2001)
03-22-2001, 05:05 PM
i have been using this timer with a little longer time of 4 seconds and using it with a Lamson holmes pir which runs on 9 volts with no problems at all.
Welby - Really hate to ask but have you made any of these and if so could you possibly post a pic of one of your boards or a layout showing continuity/circuit design. I'm having a hard time laying this out so that i'm not jumping all over the place. Don't go to a lot of trouble - if you have one fine if not I can work with it a little longer. Just would save a heap on my end. Thanks,
03-23-2001, 10:31 PM
If ###Welby can't post a pic of the sensor, I'll see what I can do Monday. A guy I work with always has a digital cam with him(don't know why). I have built two of these timers with a 2 minute delay between pics, they work great and I could post a pic or two if you want.
They only cost $6-$8 to build and you should be able to knock the cost down after the first one since most of the parts come in multi-packs.
Ksbowhunter - Thanks, That'd be great if you could. I believe I have most of the parts already, just want to make sure I have everything correct. Even if you have a general sketch as to how the board is layed out I'd probably be able to take it from there. Don't go to a lot of trouble.
On the drawing what is the purpose of R4 & C3? This differs from the Forrest Mims book. Do the Resistor and Capacitor go in the same holes?
03-24-2001, 08:53 AM
It kind of looks like Tinhorn's timer to ###me. I'm still not real sure what I did wrong when building that particular timer, but I couldn't get it to work. I built the one out of the RS book with no ###problems.
One thing I noticed is you have to have every component laid out in the sequence shown from where the battery voltage is supplied.
I'm not sure what R4 and C4 do, they are not used on the RS timer.
I will see what I can do for a sketch, my wife ###and I are celebrating 7 yrs of HELL, I mean marriage today so I doubt it will please the gods to be ###tinkering today.
Ksbowhunter2 - Being of the impatient variety I went ahead and built one. I didn't have the correct cap for "C3" so I substituted a .01uf instead of the .004uf and it still worked. I'm going to use this for the videocam to turn the same record switch on/off. I'm using a SPDT relay on the MS20 to turn the "POWER" to the timer board on/off. I just wired the points on the timer board that would've gone to the MS20 together. Seems the speed of closure(that's been my thorn since the start) on the SPDT MS20 relay was too quick and wasn't being picked up by the timer board. Turning the power on/off instead seems to be working. Thanks for the other information and if you post a pic of your board I'm sure others would appreciate it. I'll post mine as soon as I get a chance.
Thanks also to Welby and Tinhorn for this circuit - I'm finally in a good mode now.
03-26-2001, 08:13 AM
Guy's, I stepped in a big pile of Monday this morning ###and forgot to bring the timer to work to take a pic. I will post a big note on my forehead so as not to forget it.
I knew you could do it Gizz, good luck with the video cam.
03-26-2001, 10:02 AM
Sorry, I haven’t meant to shun you, but it’s turkey season and thar ain’t no ‘puter in them thar woods!
This timer is a variation of the same timer found on page 13 of ###the RS manual, “Timer, Op Amp, & Optoelectroncs Projects” (or something like that). ###In the RS manual, that particular timer is a simple one shot with a relay.
I built three of these, but couldn’t get one to work like I wanted. ###What would happen with the circuit as built directly from the manual, the timer would close its relay contacts as long as the trigger was activated and then start its timing cycle after the trigger was released. ###In other words, if you were using this and an animal tripped your MS20 and kept it tripped for exactly three minutes, the 555 timer would keep its relay closed for the initial three minutes (the time the MS20 relay was closed) and then an additional two seconds beyond that. ###(I built my timers for a two second trigger cycle.) ###This was definitely not what I wanted.
I began to ask Tinhorn some questions about how to get it to work like I wanted. ###He showed me how to turn it into a “front end” timer by changing R2 to a 47K resistor, adding R3, and then by adding C3 and R4 together. ###I don’t know how to explain it, but I think I barely understand it now. ###Changing R2 and adding R3 keeps the trigger voltage so that it’s not high enough to activate the 555. ###When the PIR relay closes, it sends the trigger signal through C3 which in turn activates the trigger with the required voltage. ###R4 bleeds off excess voltage from C3 after the 555 is reset.
I may have just made myself like look a huge idiot if I am completely wrong with how I explained it. ###If so, please excuse me. ###Like I said, I am just now learning this stuff (and know just enough to be dangerous). ###Tinhorn said that to build his timer, you would just build two of these like I have posted and “hitch” them together. ###
As modified, the timer now will activate once triggered for the specified amount of time, reset, and then ignore a continuing PIR signal if it is unbroken. ###But, it doesn’t allow for a time delay between pictures. ###For example, if the animal moves out of the PIR beam, the PIR resets, and then the animal immediately moves back and triggers it again, you will have another picture just as quickly. ###For the delay between pictures, you will have to build a timer like Tinhorn’s two stage model.
I have one of these working like a champ now, and am in the process of building about four more.
Gizz, I would love to know how this is working with your video camera.
Jayber, I think I read somewhere that the 555 timer is good for 5vdc to 16vdc (or 18vdc), but I can’t remember for sure.
Ksbowhunter2, you’re right! ###This is Tinhorn’s timer. ###Well, half of it anyway.
04-13-2001, 02:45 PM
O.K. welby I built your timer and it seems to work just hooked to a 9v battery. My question is, will it work with the ms20 modifications shown by tinhorn in his post of 3-13-01 in the tndeer site. ###He talks about a two stage timer. But I thought the idea of his mods was to use the internal timer of the ms20. Will it work with your timer? If so he is only showing 1 trigger wire. How do I hook it up? Maybe you or tinhorn can give me some help. it would be greatly appreciated!!
04-13-2001, 09:29 PM
razor, glad to hear you got one up and running! ###It took me three tries to get my first one going.
Currently, I have mine built like this while utilizing the MS20's internal time delay like you mentioned. ###If you are using the MS20's time delay feature, then you're right, you don't need a two stage timer. ###That is, unless you want to get a little fancy and start adjusting the time between pictures to a specific interval.
If you are using the RS relay on the MS20 as instructed on Jesse's page, then the wires from the MS20's relay will run to the time I have shown just as illustrated. ###Then, the timer's relay wires will run to the camera likewise.
04-14-2001, 06:52 AM
Maybe I'm confused. (Actually, maybe more confused than I thought.) ###The modifications that Tinhorn talked on 3-13-01 in tndeer are not the same as shown on Jesse's page. ###I didn't think you were utilizing the internal timer of the ms20 with Jesse's mods. ###
I built the one shot timer thinking I could use the modifications listed by Tinhorn(he's my hero). ###But then I wasn't sure when I reread and realized he was talking about a two stage. ###And like I said before it only has one trigger wire and my timer has two.
By the way, my timer seems to work, but its UGLY.
04-15-2001, 01:45 PM
Sounds like fun building one but the timer thing has me baffled. Can't I just buy one already built and solider it into place?
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