Delaying an 'on' signal

[agour]

Hey,

I'm trying to build a simple motorized camera dolly, based around this video:

If you don't want to watch the video. this is the basics. A timelapse remote for a DSLR is used as a switch in a DC motor circuit. When the remote says to take a picture, it closes the circuit and the motor moves.

I want to get it to trigger the camera too, however I need it to trigger after the motor stops turning. So say the remote closes the circuit, the motor moves for 1 second. Remote opens circuit and motor stops.

Then say after 1 second I would want to camera to take a photo. If I used another remote, it could end up running out of sync with the first, and take photos when the camera moves.

So, I want to build a simple circuit to delay the camera trigger. However I'm a complete electronics noob (more of a mechanical biased guy). I can solder things together, but I have no idea of what components etc I would need!

I found two circuits which *might* do the job, but I'm not too sure.
http://www.conrad-uk.com/ce/en/product/195901/Conrad-delayed-action-onoff-switch-kit
http://www.conrad-uk.com/ce/en/product/193631/Conrad-12-Vdc-delayed-action-timer-relay-module

It would be handy to be able to set the delay of the trigger, so it could be 0.5-10s after the motor starts.


Any help or guidance would be really appreciated!

Thanks,
Paul

 

[shrtrnd]

Look into TDR's (Time Delay Relay).
They're nice because the control circuitry is self-contained, which makes it a lot
easier to integrate into your system.

 

[Miguel Lopez]

Also monostable circuits could help, such 555, 4047. But you should design a circuit and build it. The TDR solution could be better.

 

[agour]

I've had a look at both of your suggestions, thanks for the ideas


Edit:

Had a read through the ebay description and looked online again. If my understanding is correct, it should do the job.

http://www.ebay.co.uk/itm/TIMER-SWI...al_Components_Supplies_ET&hash=item3f18431cf3


Would the trim pot be easily swappable for a normal potentiometer with a thumb screw? That way I could poke it out the case and adjust it as and when needed.

 

[shrtrnd]

Your kit from ebay is a time delay OFF kit.
You want one that's DELAY ON.
Since it's a kit, you may be able to modify it, but they make both a delay 'on', and
a delay 'off', time delay relay type.
Just in case you didn't notice.

 

[agour]

Your kit from ebay is a time delay OFF kit.
You want one that's DELAY ON.
Since it's a kit, you may be able to modify it, but they make both a delay 'on', and
a delay 'off', time delay relay type.
Just in case you didn't notice.

From what I understand, it has switches for both. One circuit opens when the timer starts, and one closes when the timer starts. They both swap when the time ends.

"When you plug the power(12v) - the relay is activated (the normally open contact /Y and G /is closed; the normally closed /H and Y/ contacts is open). The timer will keep this position until end of the set time( up to 40s), then normally open contact will open and normally closed will be closed. By restart the power, or filling the pulse with button K - the cycle repeat. "