BC has the problem of having to visit several places regularly, as in the end there will always be plants in every place and some need watering. As of now its 6 places luckily 2 of those dont need watering and in one someone takes care of it.
To get a bit more freedom BC made a very simple irrigation system before for hydroponic use (first hydro experiments) there was a design flaw (that BC was well aware of from the beginning) and another issue:
The reservoir was translucent allowing algea growth
There was only one outlet.
So BC quickly hacked up something as shown in the pictures. Note the reservoir is not shown.
Basically:
Theres a little battery, 12 Volts
On the battery there is a ZYT16G timer switch, from China
Next is a variable step down voltage regulator, from China... attached by means of confusingly thin wires, they easily take the amperage but BC must admit BC would usually have taken other wires, just had none in this place and also it serves a purpose: Can be run through a window seem onto the balkony, feels better even tho the voltage regulator is housed in a plastic container.
Next is the actual pump, fron China, its a small diaphragm pump with a small motor and it pumps strong.
The pump has a pickup hose that goes through the reservoirs lid and is stiffened with a bit of wire so it goes straight down.
On the outlet theres a new non translucent hose, preventing algea growth.
At the end of that hose theres a unit consisting of three parts: Two of them are adaptors meant to screw two hoses of variable diameter together with a common sized thread. Where you would expect the larger hose theres a machined plastic cup that has holes drilled into its bottom, slightly smaller than the capillary drip tubes, ensuring a tight fit.
Lastly theres the drip tubes of course, all are the same length ensuring uniform pressure drop across the drip tubes and thus uniform output when all are placed at the same height.
Not shown is the reservoir thats nothing but a 10 L canister that was translucent so I gave it a quick spray down with the rattle can. A few Menthae bystanders are colored now too *oops*
In the end one wants to put one drip tube into a container of known volume, say 1 L, and then run it, to measure the time it takes to put out 1 L, personally I like the numbers to be easy so I tune the pumps voltage to get something like 1L in 5 minutes. Based on that one can easily calculate how long it wants to be run for each plant every day.
Note: One could get around the need of a voltage regulator if pump & battery voltage roughly match. If one still wants the system to be "tunable" it should be layed put like a automotive fuel injection system, pickup from the tank, pump to consumer (there: engine here: drip tubes) and route any excess back to the tank through a pressure regulated line. So here: Attach the drip hoses fixture via means of a T-piece to the main hose and route the third opening of the T-piece back to reservoir, put a small adjustable valve in or clamp on there to regulate pressure and thus flow on drip tubes.
Works like a charm