trigger for digital camera

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If you already know how  to work with microcontrollers, that route would
be easier.  If you don\'t, the learning curve is quite steep and unless
you want to learn how to use them, using one-shots would be much easier.

I don\'t understand your sequence, however.

From your description, it appears this is what you want: (View in
Courier)

         __      
PIR_____|  |___________________________

        ||
         _______________________
RLYA____|                       |______
         
     -->|    ||    |

d

Hey JF, thanks for the reply. Yes, the shutter should be activated after the focus. I think your diagram is correct.

So, Relay A (pwr) is on for the entire event, Relay B (focus) comes on a couple of seconds later and stays on for 5 seconds, Relay C (shutter) comes on a couple of seconds after Relay B is activated. Then everything times out for next event.

I suppose something could be done to keep activating Relay C when an event from the motion sensor is received during the 10 seconds, but I wanted to keep it as simple as I could.

It might be easiest for you to use two 555's (or a 556) and a 4017. The first 555 (set for 10 seconds) and activates relay A. The second 555 (set for 1 second) pulses continuously whenever relay A is energized.

The 4017 counts from 0 to 9, advancing one count each time the

1 second 555 pulses. Each count has its own output pin on the 4017. Tie the needed 4017 outputs together with diodes to get the needed duration and delay. For example, you wanted a 2 second delay before relay B energizes, and you want it to stay energized for 5 seconds. To do that, use counts 2,3,4,5, and 6 tied together through diodes to turn on an NPN transistor which in turn energizes relay B. In the same manner, energize relay C. (I'm not sure when you want C to turn energize - at count 8?)

Here is a representative partial schematic: + Vcc ----+ ----- | { } [Relay] |4017 |-2--->|----+ | | |-3--->|----+ /c | |-4--->|----+--[1K]---| NPN | |-5--->|----+ \\e | |-6--->|----+ | { } | ----- | | Gnd ------+

You need to add a diode across the relay with anode tied to the collector side. The numbers 2 through 6 are the count numbers (not the pin numbers) of the 4017. Each count is connected to t6he anode of a diode - all diode cathodes are toed togehter and connected to the base of the NPN through a 1 K resistor.

You can find an example 4017 circuit here:

You would connect the output of the 1 second 555 to the clock input (pin 14) of the 4017 and would not use the

4093 circuit. The outputs would be wired as indicated above.

Ed

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To keep _from_ activating relay C more than once during the 10 second
power ON period?  That can be easily done.

What\'s the output from your PIR detector look like?  A set of SPDT relay
contacts?  An NPN open collector?

Do you have a link to a data sheet?

JF

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Re-reading your post, it seems that once the 10 second window has been
enabled and focus has been established, you\'d like to have the shutter
snap every time the PIR gets a hit during that window.

Right?

JF

Correct.

I don't have a data sheet on the PIR as it's something I picked up couple of years ago a closeouts place. It's actually a wireless PIR that, when motion is sensed, makes a receiver play some sort of recorded message ("intruder", "quit picking my flowers", "get off my lawn"). I think it has adequate range between pir and receiver, maybe

50'.

I'm planning on hacking the receiver and finding some kind of output and pushing that to the circuit.

I've been having great conversation on another forum about using a PIC (picaxe) which seems like it would be loads easier due to the timing issues. Pretty cheap too.

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Which forum?

How cheap?

JF

I

Here's the thread. The 8 pin PICs are less then $4.00 each. It's cool stuff. Check it out.

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