Backyard Aquaponics
A place to discuss aquaponics

Jaycar have an electronic timer switch for about $30 (can switch 10A). Not sure how it copes with 15min on/15 min off though.

Nova

got a link nova?

Arlec have a digital timer that is avaiable at Kmart. Problem is it only has 10 on/off programs - not enough for what I need to do. I expect the one available at ageofaquariums would be the same. When I get the time I will start playing around with autosyphons, though would not use on unless I was sure it was going to operate all the time.

If people were confident in a little soldering its actually quite an easy circuit to make a variable on / off cycle timer, but i'd hate it if anyone got electrocuted................

Correct me if i'm wrong, but in our flood and drain setups we don't really care for a 24 hour clock, we just want an ON period of X minutes and and OFF period of X minutes, repeated for ever. Yes?

less than 10 components

Jaycar, as in Jaycar electronics in the city?

Do they have a website, or just a store?

www.jaycar.com.au

they ave multiple stores in multiple states

Actually i think they have a kit based around the 555 timer chip (which is what i was thinking with the last post) Now that would be a safer option for people to dabble in.

This is the one i was talking about, i think............

VB, ill move these posts to a new section very soon

This is a better one...........
http://www.jaycar.com.au/productView.as ... &SUBCATID=

and i have the book with the kit description and build instructions. I can "make these available" to people......................

Spot on Steve. Ability for the on and off times to be different, but that is basically it. Also, woudl want to be able to adjust if changes to the system change the cycle times. At present, if I was able to, I'd have my timer running 15 mins on and 30 mins off.

that second link kit would do it easily. i'm fairly sure its based around a micro processor, so will have to dig up the book to see if the periods can be extended. If its based on a 555 timer chip (don't think so) then this is no problem

Nice link Steve... I've already got the arlec digital one but it is a real pain to program, and if it starts giving me greif I will have a crack at that.

VB, that's hilarious, I haven't had a go at growing anything illicit, just yet anyways , but I find myself elaborating on WHY I am buying stuff whenever I go to hydroponics shops. They must hear lots of "cover stories" every day of the week....

Ya sure this one would do the trick?....... wouldnt it be positive/negative edge triggered (ie thermo fans/windows staying active after the ignition is TURNED off, this being the trigger to set the on delay/ off delay functions of this particular timer) making it dependant on some sort of input to turn it on

You are correct for the first mode, which is monostable (oneshot) the second mode is astable (multivibrator) KEEP IT CLEAN AM Will try and dig up the book tomorrow

Those digital timers are crap when the power goes off.

?? C1, um when the power goes out the timers have nothing to to time anyway...................and the commercial ones have battery backup for the date/time, the DIY one is simple based on a repetative time base so it doesn't matter.