DIY Cycle Timer / Recycle Timer for Aeroponics

[OrganicDIYGrow]

I'm looking for a cheaper solution to the expensive $80 or more Cycle Timers that allow those with Aeroponic setups to run their pump @ 30sec ON, 30 sec OFF, and repeat forever.

There just has to be a cheaper solution than an $80 part. (I say $80 because that's the cheapest I've seen them on eBay). I'm willing to put in the effort to make/modify one and write a tutorial.

I've tried searching to see if anyone modified a Intermatic Timer (the popular kind that have anywhere from 6 to 24 ON/OFF settings for a lived in feel, or the ones we all use for our lights), but the best I could find was someone mentioning they opened one up and glued some gears together to get somewhere around 40-70 seconds cycle timer. Unfortunately they never got around to making a tutorial for the mod. Modifying Christmas light timers could be a possibility as well.

The other route I thought about was to build a simple instruction circuit board type device (do my own soldering, and programming a chip) to do the timing for me and simply provide an electrical current ON or OFF at the timed interval that would do something simple like flip a light switch, or power a motor that flipped a light switch, etc..

Does anyone have a solution to this, or can help me expand my idea a bit to be more realistic? Any info is helpful.

Side Question: Do these $80 cycle timers have special wiring in them that turns the pump off "better" (nicer to electronics wear and tear) than a dead ON/OFF switch? If not, why are they $80 or more?

[Don Piano]

do you know about electrical schematics? If so, you can make one from a couple ICs, a dual flip flop and a 555 timer, a few resistors, a couple capacitors, some diodes, wire, and a solderless breadboard. you can get anywhere from 1sec on/off to 2hr15min on/off

If you are interested let me know and I will post the Detailed plan.

[Don Piano]

Parts List:
One solid-state relay (you choose the amperage to suit, I used 18 Amp / 120V, (US$6.50 used).
Others available like it at allelectronics.com

A DC power supply (anything from 5 to 9V DC is fine, from an old
"DiskMan").

One power-strip.

One "Bread Board" (We will build our little circuit on this, US $3 or less).

Four chips, some jumper wires of various lengths, a couple capacitors, and some
resistors.

Two wires approx 1’ (use some cord from the DC power supply mentioned above).

you won't believe they charge US$90 for these in many Grow shops!

Note that EXACT product codes are not important in selecting circuit parts. But, what IS important is for the numeric part of the code to match mine and for the number of pins to be the same. For example, if you found a 16PIN "TC4013BP" that would be fine even though the one I have says "TC4013BF". The capacitor can be any type, but if you get a polar one
like I did, make sure it goes in the proper direction. The resistors don't
matter so much, just get the res values correct. If you cant get a 130kohm resistor use a 100kohm and a 30kohm connected together, the same goes for the capacitors.


Setting up the breadboard
The Breadboard has two sides, which are electrically insulated from each other.We will call the left side GROUND and the right side POWER. We supply power and ground to the board by plugging our DC Power supply leads into bottom of the board (as shown). I recommend soldering these connections to pieces of (more rigid) jumper wire. You must match the positive wire from the power supply to the positive (right) side of the breadboard, and the negative lead to the left side. Usually, the positive wire will look different (e.g. have a white stripe like mine). The outermost holes on each side of the board are used to distribute power and ground (respectively) to an entire row of the board
The chips have either 8 or 16 pins each. The pins are numbered counter-clockwise (from bottom left of chip) as shown.


Building<?XML:NAMESPACE PREFIX = O /><O:P></O:P>You may connect the power and ground connections from the DC power supply anytime but DON’T PLUG IN BOARD DURING ASSEMBLY!

Note: When putting on the chips exact row positions don’t really
matter, just as long as the chips go in the order specified and are "down
the middle" of board, with lettering READABLE FROM THE GROUND SIDE.

Install all the chips

Chip#1 is the 555 timer chip.

Chip#2 = 4020B counter chip.

Chip#3 = another 4020B chip.

Chip#4 = 4013BF dual D-type Flip Flop.







Connecting the relay:
The Solid State relay has two ends, the DC control end, and the AC power end. ***Caution*** AC current can kill you, so please be careful. Make sure the power strip is UNPLUGGED.

We begin by slicing through the outer plastic of the Power Strip's insulation, about a foot or so from the plug. Peel back the insulation to reveal three wires (white, green, and black). The black one is the POWER wire, the one we will splice into the AC side of the relay. Cut the black wire and cut and peel back some insulation from each cut end. Make a small loop on each cut end, and screw down these loops under the relay's screws (AC end). [See picture for details]

Connect two small (8-12") pieces of wire [see parts list] to the Relay's DC
power and ground screws. Tape up the entire relay (especially the AC end) with black electrical tape (or duct tape). This will prevent any contact shorts and improve safety.

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To Set ON/OFF times:

Chip #3 controls OFF time.
Chip #2 controls ON time.

To change these times, simply plug the Yellow or Green wires into other pins (on Chips 2 and 3) as follows:

The following times are valid for chip 2 (ON time) and chip 3 (OFF time):

<CENTER><TABLE style="BORDER-COLLAPSE: collapse" borderColor=#000000 cellSpacing=0 cellPadding=0 border=1><TBODY><TR vAlign=bottom><TD align=middle>Pin #</TD><TD align=middle>Schematic Pin </TD><TD align=middle>Delay Time </TD></TR><TR vAlign=bottom><TD align=middle> </TD><TD align=middle> </TD><TD align=middle> </TD></TR><TR vAlign=bottom align=middle><TD>9</TD><TD>Q1</TD><TD>2 sec</TD></TR><TR vAlign=bottom align=middle><TD>7</TD><TD>Q4</TD><TD>16 sec</TD></TR><TR vAlign=bottom align=middle><TD>5</TD><TD>Q5</TD><TD>32 sec</TD></TR><TR vAlign=bottom align=middle><TD>4</TD><TD>Q6</TD><TD>~ 1 min</TD></TR><TR vAlign=bottom align=middle><TD>6</TD><TD>Q7</TD><TD>~2 min</TD></TR><TR vAlign=bottom align=middle><TD>13</TD><TD>Q8</TD><TD>~ 4 min</TD></TR><TR vAlign=bottom align=middle><TD>12</TD><TD>Q9</TD><TD>~ 8 min</TD></TR><TR vAlign=bottom align=middle><TD>14</TD><TD>Q10</TD><TD>~ 17 min</TD></TR><TR vAlign=bottom align=middle><TD>15</TD><TD>Q11</TD><TD>~34 min</TD></TR><TR vAlign=bottom align=middle><TD>1</TD><TD>Q12</TD><TD>~ 68 min</TD></TR><TR vAlign=bottom align=middle><TD>2</TD><TD>Q13</TD><TD>~ 2 hr 15 min</TD></TR><TR vAlign=bottom align=middle><TD>3</TD><TD>Q14</TD><TD>~4 hr 30 min</TD></TR></TBODY></TABLE></CENTER>

***Remember that the pins are numbered from 1-16 and arranged counter clockwise from bottom left of chip. Do not plug into any other pins besides those listed in table above!***


The board and relay could be fastened inside of a small plastic case with holes cut for the power strip cord ends. Make sure to keep components from touching though. Simply plug in your appliance into a spot on the power strip, plug in the strip and DC power supply, and set the ON/OFF times.

Here's the schematic of the completed cyclestat.

Be sure to add a filter capacitor as the schematic indicates to ensure proper timer functioning.


Below is the timer layout, featuring an "automatic on" function that restarts the timer in the ON position when power is applied. The resistance/capacitance values on the RC circuit are subject to what works. (The stated values worked for me, It's all about resetting the chips for long enough time intervals when power up occurs -- play around to find what works best for your timer.)

Shown Values:
Res. at bottom (added RC circuit) = 1K ohm
Res at middle = 10K ohm
Cap. at bottom (RC circuit) 68 uF.



I hope this helps. I may have forgotten stuff. Its 153am and I am tired and buzzed. If you have any questions or need clairification on anything i will be back sometime to check.

-Don Piano

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This can also be used to control co2. with This timer, a cheap thermostat ($20), dehumidistat ($30) and a couple of relays can substitute for a climate controller with co2 sequence control.



Good sources for the parts are
Allelectronics.com
Ebay
RadioShack
and try your Local hobby stores

[OrganicDIYGrow]

Don Piano: These are great instructions. Thanks a bunch.

This is one of the solutions I was looking for.

I've messed around with a breadboard only a handful of times, so this seems a bit daunting, but I think I can handle it with your instructions.

Would you happen to know how much all the parts you mention cost in the end?

I like your instructions, and I'm going to read them more detailed when I get the time, but for now I'm still looking for a more universal solution more people will be willing to try on their own. Or maybe someone can build these for people at a reasonable cost if the parts don't cost too much.

Anyone else have a solution to a cheap Cycle Timer?

[Don Piano]

This is as cheap as it gets. Its pretty easy to make. Any help you need as far as tech, I got you. In the end it cost under $25, If you want to make it cheaper you get a piece of perf board for $2 (instead of the solderless bread board $7) But then you have to solder all connections. But this is simple. Just research the prices on the sites that i listed in the last post. Radioshack.com has most all of it; the 555 timer chip, the resistors ,capacitors, and the diodes, plus the perf board. The relay you can get from allelectronics for like $3 (check them for other parts too to cut down on shipping)

The 4020 chips are tough to find. Ebay is the only real source for those.The proper name is 14 stage 16 pin binary ripple counter (use any of that in the search on ebay.

the 4013 dual flip flop can be found on allelectronics.com as well for $0.35


You can do it!

[Don Piano]

http://www.apogeekits.com/start_stop_timer_k2579.htm

This is a very simple version of what you need. Not as sophisticated, no assembly required, and ULTRA cheap, but it is not as controllable as mine. It should serve your purpose though for 30 sec on / 30 sec off. However, If you do need a huge range of timing capabilities you need to go with the above plan.

[green thumb]

http://cgi.ebay.com/IDEC-Electronic-...QQcmdZViewItem

these things are so cheap on eBay . . . .

[Don Piano]

And that will work like either of the above?
Is this what you use?

[OrganicDIYGrow]

Originally Posted by green thumb

http://cgi.ebay.com/IDEC-Electronic-...QQcmdZViewItem

these things are so cheap on eBay . . . .

I've attached an image of the device mentioned on eBay.


I'm with Don Piano when we ask if that is what you use.

Either way how do we hook it up to do our bidding? What other devices do we need?



I'm looking at all these options and am compelled to create a tutorial for the best choice when I tackle it as a project. Anyone else want to join in on creating one their very own cycle timer?

[Don Piano]

I also have had thoughts of making a tutorial for the cycle timer. If you want a hand I am right there. I have helped many friends build them. They are so damned expensive to buy when you can build them for 20$ to 30$, and no one has a tutorial on how to make one, But you can find plans for cheap aero cloners, hydro setups, and homemade carbon filters everywhere without even looking.


With the design that i posted the first time here, you can actually make it reset its cycle with a simple automotive relay($3), a wall outlet ($1.50) and a wiring box ($.19)so when using it for co2 augmentation, it will shut off when the exhaust is running and immediately restart pumping CO2 when it shuts off. A very cheap addition for some added versatility. ( ask and I will reveal )

[green thumb]

the relay I linked to is a delay on make OR symmetrical interval timer with a 110VAC coil; many other types available

yes, I use these along with asymmetrical, one shot, and delay on break timers/relays in lighting, feeding, and environmental control panels

the linked relay can be used as a delay on make timer/relay to provide a restart delay for HID lighting (ck contact rating and loads) to deal with power outages/hot restarts

the linked relay used as an interval timer can cycle the feed pump (and return pump in an ebb & flow setup)

Generally speaking, these relays and timers are part of the control system and merely switch the power on and off to specific devices. Using an Intermatic/Dayton electromechanical timer, take the switched output as the control source and connect to the coil (other side to common). Then connect the power and load to the timer contacts, if the load is over 5A use the timer to control a 20A contactor. N.B. The code requires that these relays and such be inside a machine or enclosure, I put them on plywood but such is not correct.

FWIW, I scrapped 8 electromechanical timers for a Lakewood 66 controller which is a 4 channel microprosser based timer - love that battery backup.

[Don Piano]

Very nice. It looks a little complicated but I guess mine don't look like I'm making pancakes either.

Do you have any ideas on a 15 min on delay timer (not to thread jack) that don't cost $80?
(for preventing hot starts on the HIDs in case of power outage)

[green thumb]

thats what the blue timers are in the photo (top center) ATC 319D (DOM only)
many of these things on eBay
http://business.search.ebay.com/time...1QQsacatZ78208

sometimes bases are included, or not
lots of used stuff cheap from rebuilds, new often costs no more

in that panel there are 2 isolated 220VAC circuits, plus the 110VAC stuff

[OrganicDIYGrow]

These setups are a bit advanced for me (mostly cuz I don't know the lingo of relays, 110VAC, controllers, loads etc.), but I bet others can get some good info here.

I'm gonna keep gathering info for Don Piano's setup and keep looking into modifying an existing timer to change the times it can handle.

Thanks to all that have commented, and if anyone else has some ideas, please share.

[OrganicDIYGrow]

This Grasslin timer says it has 48 on/off settings for $20.
So this would work for a 30min On and 30min Off recycle timer right?

If it was 24 on/off settings you could only get as low as 60 min on 60 min off correct?

I think 30min on/off would be OK in my setup, but this timer definitely wouldn't work if I needed the 30 seconds on/off setup.