Backyard Aquaponics
A place to discuss aquaponics

Ah, but les, you only need your "modified inverted PVC trapdoor" to go one way. Even a slight spring tension (better pick up a few of those too) will keep it closed. If it were a ball or butterfly valve spindle you were trying to actuate then Yep, yu'd need to reverse it, but hello, you will have in your possesion a smart relay, better than any power control relay!

Mental note, nod and smile when the old people talk................

Okay, I may be looking at this the wrong way, here goes:

Trap shut (no Mon not "keep yer trap shut") and is held in that position by the actuator arm, pulse from 1 shot, actuator motor turns and trap opens - actuator stays in that position.

Sensor senses and reverses polarity to the actuator motor pushing trap shut again, the actuator holds the trap open/closed dependent upon where it is on the gears, tha actuator motor only turns with a pulse from either "one shot" - isn't this how it works???

Not in my experience. the reason they stay open and shut in cars is the levered door lock mechanism. The actuators themselves actually "hang loose" when power is not applied.

SO, in your case you'd either have to have them spring loaded return (only slight spring tension will be required) and powered up for as long as you want them open.

OR make up a lever cam type thing that holds the trap open or closed when actuated.

Thanks for that - will find out how to connect when I get one, no use theorising too much

hasn't anyone even tried my FAB smart relay program get? :laughing2:

Royale put up some info on it as an OEM version and I pm'd him on it - gonna get the trap(s) working 1st then scale up - take it easy young fella, don't rush these things

Here yar Steve (and others), bought a kit and flap, added some pressure when flap open so it won't close back down, water pressure will hold it down.

This is a proto type (Stage 1) but if anybody wishes to comment please do so.

Set up the actuator on open and close positions so that all can get an idea, pics of open/close positions

Les, cut and paste my PM to you here if you want, had some good info, save me typing it again!

Another point to make regarding duty cycle of the actuators is; they are actually motor driven, not a solenoid, so operating current dramatically increases when motor is stalled (ie at the end of the stroke) more reason to make your system a pulse to open / pulse to close. more mechanical thinking, but you'll probably burn the actuators out the other way.

my car is in pieces at the moment because of cheap actuators.

The actuators are going to be pulse driven, working on holding the flap in place after activations.

Interesting Fizzy - on the web site it says "beware of inferior actuators", hopefully that means these are good - intend to keep them under regular surveillance when 1st installed - got a long way to go before then tho

Hahahaha, was just listening to my system F&Ding in the darkness, and realised that you neibours will be hearing Click...........click..gurgle..gush..click LOL

Found some cool albiet expensive analogue sensors online..... http://www.envco.info/0004Water/0415Process_420

They have; temp, DO, power of hydrogen (pH), conductivity, turbidity and even suspended solids probes.... I have email them for some prices. I don't expect them to come too cheap though. Most of them have a 4-20mA output, so a conversion to voltage will be allthat is required for analoge inputs... then software to do the calculations.

yep, and all that means is a 250 ohm resistor across the output voila voltage output 1 to 5 volts or a 500 ohm resistor for 2 to 10 V

Thanks Steve.... I didn't want to freak them out... I think they can handle your solution ok.....

What do you think of the probes, Steve? Are they suitable with the PLC's?

actually haven't opened the link yet, was just home for a few minute before......am getting to it