Backyard Aquaponics
A place to discuss aquaponics

How about incorporating the 5VDC supply into the same supply that most people would be using to drive their pump... ie. (240VAC or 120VAC), then probably with a very small transformer and rectifier for the 5VDC??

Watching this topic with interest! I would love a DIY timer that is 120v and has a broad setting capabilities... Can solder and follow directions, but pretty hopeless in trying to design something of this sort myself...

Thanks to all you electronic gurus who are pondering/contributing to this effort!

CB

Parts list is looking like this (Jaycar Prices)
Vero board $4.25
1 x 555 timer $0.62
1 x 74LS00 $0.30 (quad 2 input NAND)
2 x DIL Switch $3.00
2 x counter
4 x 74LS86 $2.72
(quad 2 input XOR)
3 x 74LS04 $1.20 (hex Inverter)
2 x 74LS30 $1.00 (8 input NAND)
16 x resister $2.10

so total so far is $15.19 + the counters... still working on that as 8 bit counters are rarer than I thought, so I may get 4 4bit counters instead for convenience. Jaycar has little to offer.

Scratch that... redesign... Found a nice 74 series counter with presets.
So we don't need the XOR comparitor...
Such it is then that 2 inverter chips, 2 8in NAND chips, A quad NAND chip are no longer needed
so revise the shopping list to:
Vero board $4.25
1 x 555 timer $0.62
2 x DIL Switch $3.00
2 x counter
1 x 74LS04 $0.40 (hex Inverter)
16 x resister $2.10

$10.37 plus the counters, of which we'll need 4 cos they're 4 bit.

Now I only need to ensure the startup condition sets the preset, and all should be well, I may need an extra chip for that.

Keep going Kuda

One thing - I have not come across a 5v activated 240v switched relay before...??

If you can design it up, I'll get the parts and build it

Soldering is extremely easy to do, especially with nice shiny wires / pins.

Yep like countryboy, I too am following this thread with much interest.
Although Kuda sometimes your speaking a foreign language to me ,
thanks for putting in the time and effort to design what will surely be a fix for a lot of people’s timing issues.
Keep up the good work buddy, I’m keen to see what you come up with

Oh and I have only ever soldered once in my life and can recall it being not all that difficult at 1st,
can also follow instructions so if you do come up with something relatively easy to build I could put one to good use (my little system could handle less pump 'on' time, atm it's 15 on 45 off) so will have a crack at building one

Ok I have put together a design for a pic based timer.

The timer can be used to control a relay which can run of it's own supply. An opto couple isolates the circuit from the relay.

The timer has independently adjustable on and off times and is adjustable from 1 sec to about 179 minutes.

Parts required

Experimenters Board $1.88
PIC16F630 Flash 14-pin 1kB Microcontroller $1.88
14 Pin IC Socket $0.08
4N35 6 Pin Transistor OptoIsolator $0.47
Red 5mm Round LED $0.10
Small Black Tactile Switch $0.31
10 Position DIP Switch $0.94
LM1117T - 5.0V Low Drop-Out Regulator $0.88
2 x 470ohm 1/4W 5% Carbon Film Resistor $0.12
11 x 4.7kohm 1/4W 5% Carbon Film Resistor $1.32
0.33uF 100V Mylar Capacitors $0.15
0.1uF 100V Mylar Capacitors $0.15

Parts Total $8.28

If people would like I could provide pre-programmed PIC's for $8.00

If there is interest I might be able to make a PCB available. But it is likely to cost about $20 to make and drill.

The timer is adjusted by setting the 10 port dip switch (S1).
one port selects on or off timing
one port selects minutes or seconds
seven ports set the count from 1 - 127
The total time is the sum of minutes and seconds

When the time is set press the tactile switch (S3) and hold for about 2 seconds, the led will flash when the new time has been entered.

Example board design

Here is the circuit

The Pic can be mounted in a 14pin IC socket so soldering will not harm the micro.

Woops I getting muddled it's 129 minutes not 179

And I nearly forgot, if you can wait this place has great prices, but it takes 2-3 weeks for your order to arrive.
http://www.futurlec.com.au/index.jsp

And for anyone that has access to a pic programmer I am happy to provide the hex file.
For those that would like to try to make a PCB I can try to provide the files for that too.

I like

Ok there has been a request for more information about the control of the car door actuators that I use in sequencing.

I have used two methods of controlling them one uses relays the other transistors.

The actuator is based on a DC motor that uses a gear setup to convert to linear motion.
This mean that you need to reverse the polarity to open or close it. The one I use have been designed to operate on 12v they travel the linear distance in about 0.2 seconds. So you need to pulse them for that long if you leave them on for too long you will burnout the dc motor.

With the siphon system I use a sensor to detect that the siphon has kicked in and then switch to the next bed. My original setup used flap valves to activate a switch it relied on the pressure generated by the rapid flow of the siphon. This was ok but the switches were unreliable, despite my efforts they got water in them and started to give trouble after 6 months. If you used waterpoof micro switches you would be ok. However my new setup is Pic micro based and allows me to check the water level in the siphon.

The sensor is based on 2 plastic coated wires that have the tips exposed and set about 1/3 down from the top level of the siphon. The micro checks for the presence of water every 2 seconds, once it detects water it waits till it is clear again then switches to the next bed. This ensures that the siphon fills, kicks in and then drains a bit before switching the pump over.

Since I am using siphons there is no reason to wait for the bed to drain as it is emptying faster than my pump can pump, so I use the same trigger pulse to switch 2 relays one for the bed that is closing and one for the opening bed, the polarity is reversed due to the way it is wired.

novaris,
If you were to use a car door actuator to open and close a valve..... Just one valve.......
and you wanted to be able to be have that valve open and close essentially as if it were hooked to a repeat cycle timer.
You Want to be able to adjust the open and closed time.

How would you make a really simple small single unit to control one of those actuators. No added sensors needed.

When the pic detects the water receding it switches on the transistor for the next bed in the sequence, which switches on the relay. The relay is wired to drive the open bed to close and the next bed to open. The circuit is shown for 3 beds but you could do more as it is I am only using 2 of the three at the moment I just alter the links on the output jumpers to cycle back from the last to the first.

J1, 2, & 3 are the motor drives j8, 9, 10 allow me to link the sequence for 2 or 3 beds.
J4, 5, 6 are to the water level sensors.

With the new greenhouse setup, I used a different approach because I want to have all beds closed during the drain time. In this case I used a H bridge, the circuit diagram is too big to upload but it used transistors instead of relays.
http://en.wikipedia.org/wiki/H-bridge will give you the general idea.