How to use a 555 timer to switch a switch?


I was thinking about making an intervalometer circuit for time lapse use on cameras. I was thinking of using this link https://www.instructables.com/id/Time-Lapse-Intervalometer-for-SLRs-with-555-timer-/ .
I was thinking of adding a 22uf cap, as well as the normal 220uf cap, and then adding a 2200 uf cap, for a highly flexible range of time (ranging from a few seconds to about an hour), choosable by switch. I am starting to run into trouble at the camera connection itself. While i am fine with a cable, i would rather go with a wired remote, and using it to do the equivalent of pushing the remote buttons (instead of going through the cable itself). So i need a way to connect the two switch points electronically, rather than mechanically. Also is there a way to have it focus first, then take the photo? This circuit would also be good for cameras that do not have remote connectors, just go in to the camera and solder the switch points up, then hook them to this circuit. Would also work with a wireless remote. Hook it to the remotes switch and go from there. Just need a little help finding out what to do to get it to work the way i want to :) Thanks

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For long delays, the 555 is very poor.

To switch the camera, I'd get a very small relay, with normally open contacts.

Steve
astroboy907 (author)  steveastrouk7 years ago
Because of stability issues or just the prolonged period of time?
I thought 5 minutes would be a little short for some of my projects. Might add a 470uf cap instead of 220 uf? Would get me about 10 min between shots. how about this relay: http://www.taydaelectronics.com/servlet/the-1887/Mini-Relay-SPDT-5/Detail
i assume since its SPDT there is always one contact open?
Thanks :)
Stability. The capacitors leak charge depending on their temperature amongst other things. The classic fix is to make the thing clock a fixed cycle, say 1 every second, which is easily doable, and then divide the clock by 100 or whatever using a single logic chip like a 4522, so 100 ticks makes the output change.

That relay is fine, if a little overrated for this application !!!
astroboy907 (author)  steveastrouk7 years ago
So pretty much its a hot-or-miss situation sometimes with exact timing? Might be better to find a kitchen timer and get it to auto reset. Hook the alarm speaker up to a relay and have that control the camera.... might be worth a shot :)
Thanks for your answers :)
astroboy907 (author)  astroboy9077 years ago
hit-or-miss. they really need to get an edit button on this :)
He he. Yes, 555 on long delays, not good.

An Arduino is probably better these days - a pot for analogue time, and three range switches, a crystal and your relay. Job done.

There used to be some really nice long delay analogue timers, but they have long since been replaced with microcontrollers I'm afraid.

Steve
astroboy907 (author)  steveastrouk7 years ago
Looked around and found some really cheap ones, mainly a dollar store one with memory (to recall the last countdown made) i was wondering if it might work to hook the speaker wires up to the second button pin (the output). Would it work in setting that pin high? making it look like the button is letting energy through, when its just energy from the speaker. would not work with a normally open switch though. and would be safer to have relays. But it looks like i found something. I see a nice project ahead....

clock link

http://www.dollartree.com/catalog/search.cmd?form_state=searchForm&keyword=timer&x=0&y=0
Worth a try. Stick a diode from the output to your relay and see what happens, or better, to a transistor, and then to your relay.
astroboy907 (author) 7 years ago
oh. one last question. any recommended transistors?
astroboy907 (author)  astroboy9077 years ago
using 3904s :)