Photoelectric controlled latch for chicken coop

[rollyb]

Hi All,

I am a newbie, and would like your help.
I have searched far and wide for a solution for this problem and I reckon that there is a real opportunity of the person who can design the following:

In essence this is a mechanism to open a latch when the sun comes up! The mechanism must be powered by a 12v battery and this battery must incorporate a solar trickle charger mechanism.

I know from visitng many forums and during my time spent looking for such a device, that there exists an increasing number of people who are keeping chickens and a definite need exists for this item.

I have attached a very rough outline below.

 

[dougy83]

I think you can simplify your idea a little:
--> the solar cell can be used as the light detector as well
--> the battery can be replaced by a capacitor (or 2)

A solarengine circuit comes to mind (**broken link removed**). This works with a small (cheap) solar panel charging a capacitor. When the capacitor voltage reaches a preset level, the motor/solenoid/etc. is turned on and the charge stored in the capacitor is dumped into the motor/etc. This repeat while there is any sun out. You could disable the repetition after a min or so, if you wanted to, by adding a few extra components.

 

[MrDEB]

battery montor and one shot

use the one shot (5 seconds) to turn on the solenoid.
a second one shot could be implemented to turn on a bell at dusk. condition the chickens that when the bell sounds, its time to get into the coop.
the battery monitor is a little overkill but very accurate.

 

[Mr RB]

...
a second one shot could be implemented to turn on a bell at dusk. condition the chickens that when the bell sounds, its time to get into the coop.
...

Pavlov's Chicken?

 

[dougy83]

MrDEB, you might want to check the triggering portion of the 'one-shot'

 

[MrDEB]

photo transistor gets light and trigger input goes low
is there something I missed?

 

[dougy83]

photo transistor gets light and trigger input goes low
is there something I missed?

That's what I thought. Won't the trigger input be pulled low all day though (and not actually provide a timed pulse out)?

 

[MrDEB]

one the trigger impulse goes low the 555 only outputs one pulse.
it triggers on a low going pulse if I recall.
**broken link removed**
the link has lots of circuit ideas (knowledge)

 

[dougy83]

one the trigger impulse goes low the 555 only outputs one pulse.

True, the output will output a single pulse, having a minimum period set by RC; but if the trigger input is held down for longer than 1.1RC, the output will be high for as long as the trigger is held low.

it triggers on a low going pulse if I recall.

The output is _set_ high when the trigger is low, and _reset_ low when the threshold is high; trigger pin has precedence over the threshold pin however. Neither threshold or trigger pins are edge-triggered (both are level triggered).