Backyard Aquaponics
A place to discuss aquaponics

my apologies frank, i did misread it!

No vb, i DID read YOURS just thought i'd make a complete post

Window motors generally do not have limit switches though. the drivers side (sometimes the front passenger side have another method of breaking the motion ( i think it might be a current sensing bi-metal device). get into your car at night with the interior light on, try and close an already closed window. notice the interior light dim? Means that a limit switch is not being used.

LOL, thats what i get for writing long posts! even technophobes like VB beat me to it

all window motors (should) have some device that automatically switches them off, else they would burn
suppose a heavy object came to lean on a switch and keep it on, that could cause a fire

I wouldn't know how it is called in English, but I would call it a "latch" relay
it is where you push a button once and the relay latches on until some other device (i.e. a limit switch) shuts off the current
they are simple and easy to wire yourself

anyway, limit switches are very cheap and easy to wire too
see i.e the small reed switches you can buy anywhere for alarm systems to protect your house windows against burglars

just check if they can cope with the amps for direct switching, else use them to switch a relay witch then switches the current to the motor
all very simple

frank

[quote][No vb, i DID read YOURS just thought i'd make a complete post
/quote]

So what do you think about those Jaycar motors. I'm not keen to get a secondhand wiper motor - prefer to start new given the critical application - and a new one could be a bit costly.

Will have to go back and read your posts again Steve - but I'm not sure if you addressed the issue of reversing the motor for openning/closing.

Never used them but have a look at Oatley’s “Motors” page
He’s got more to choose from.
http://secure.oatleyelectronics.com//index.php?cPath=53&osCsid=70686beadbfd76bb65655451c2ba812c

Thanks Steve S - will have a look. The good thing about Jaycar is that I can just rock up and buy their stuff. The motors I linked to seemed to have fairly decent torque ratings - not that I would really know. I linked to them in one of my posts on the second page. I'd be happy for comment from anybody who knows about these things

know what you meen, I have Jaycar, Altronics, and Rockby practically around the corner
and its on my way to/from work

id go the wiper motor. it comes with two speeds already and an "arm" off the shaft.

checked one of those motors, is still nearly 3 revs per second wiper would be about 1 on slow speed i think

You could use a small water pump to open the door instead of a motor with limit switches etc.
Use the weight of water (ala barrelponics) to open the door against a bungee or similar. When darkness arrives the pump turns off, water drains out and the door closes with bungee assist.
You may not need an additional photocell trigger circuit if you use a solar powered pump

bloody hell. it would certainly work! you could even use a counter weight on a pulley.

Good stuff, hex!

I don`t know much about chook pens but if the door is like a vertical sliding shutter it should be easy enough to modify.
Bungee the top of the shutter to force it to close upwards and use the weight of the water container to close it downwards.

hehe..that should be "open" it downwards

but you would have to keep the pump running all day (or all night) to keep the door open (or shut)
not very practical

frank

If its a solar powered pump to negate the photocell switching, it won`t be costing anything to run anyway

ok, I'll go strip a car wreck and have two (or four) nearly ready to fit hen door systems with switches and all,
and the same trip will leave me with a ventilator (for ventilation) and a windscreen wiper motor (for a piston pump) and four electric door locks (don't know yet what I will use them for)

better than having to buy a solar panel and a pump and build a system with pulleys and a bottle and the water reservoir from which the water comes and the piping to where the overflow goes (this can be to the same tank, but this will regularly need topping up)

If I decide to incorporate a solar panel, it will be to charge my battery
makes much more sense

frank