Maker Pro
Maker Pro

I laugh and think - Solenoid Valves

Hi all,

Well, thought I'd get into a bit of water conservation, and as I have
quite a few micros around, my thoughts turned to turning water on and
off.

As a lot of power supplies are 12v DC I initially thought that there
were heaps of cheap
solenoids out there ready to buy. Unfortunately I must have been
somewhat deluded as there are not many 12v DC solenoids in existence -
maybe more 24v AC.

Checking on Ebay showed some in the USA at about (from memory) $AU10,
but being the ever great Australian product consumer, thought I'd find
the same here.

Well, as it turns out, after submitting a request to (apparently) the
largest supplier of solenoids in Oz that the equivalent cheap plastic
solenoid here is around $AU75.00
FMD! What justifies this great markup?
 
P

Poxy

Jan 1, 1970
0
Hi all,

Well, thought I'd get into a bit of water conservation, and as I have
quite a few micros around, my thoughts turned to turning water on and
off.

As a lot of power supplies are 12v DC I initially thought that there
were heaps of cheap
solenoids out there ready to buy. Unfortunately I must have been
somewhat deluded as there are not many 12v DC solenoids in existence -
maybe more 24v AC.

Checking on Ebay showed some in the USA at about (from memory) $AU10,
but being the ever great Australian product consumer, thought I'd find
the same here.

Well, as it turns out, after submitting a request to (apparently) the
largest supplier of solenoids in Oz that the equivalent cheap plastic
solenoid here is around $AU75.00
FMD! What justifies this great markup?

A 1" Richdel/Irritrol solenoid with an AC coil should cost about $20-$25.
The 12v DC coils for these are usually the latching type - a pulse with one
polarity opens the valve, a pulse with the reverse polarity closes the
valve, requiring an H- bridge or dual-pole relays to control each valve. The
catch, as you've found is that the DC latching coil costs $30-$40, which is
bloody expensive compared to a 1" valve, however the same coil is used on
much more expensive valves, such as 2" units.

If you are not running high flow rates, why not hack one of the
previously-mentioned Holman tap-timers - they sell a $20 2-knob version
which has a neato motorised ball valve. The catch is the fluid path, while
straight, is only about 8mm diameter - fine for drip irrigation but probably
not for sprinklers or pop-ups.
 
R

Robbo

Jan 1, 1970
0
Hi all,

Well, thought I'd get into a bit of water conservation, and as I have
quite a few micros around, my thoughts turned to turning water on and
off.

As a lot of power supplies are 12v DC I initially thought that there
were heaps of cheap
solenoids out there ready to buy. Unfortunately I must have been
somewhat deluded as there are not many 12v DC solenoids in existence -
maybe more 24v AC.

Checking on Ebay showed some in the USA at about (from memory) $AU10,
but being the ever great Australian product consumer, thought I'd find
the same here.

Well, as it turns out, after submitting a request to (apparently) the
largest supplier of solenoids in Oz that the equivalent cheap plastic
solenoid here is around $AU75.00
FMD! What justifies this great markup?


What do 1/2" garden retic solenoids cost? They are AC - perhaps drop the
voltage down & run off DC??
 
Hi Poxy, and thanks,

I would hack a tap-timer, but common sense suggests that a 12vDC
solenoid should be available, but not at $AU75.00 (unless you wish to
rip-of people)...

Thanks again Poxy for the great ideas though.
 
BTW, Please excuse the rather strange topic. I was thinking of the
lyrics of a long-gone Australian group - Anyone know what the song/
group is?
 
T

Terryc

Jan 1, 1970
0
FMD! What justifies this great markup?

Could be economies of scale.

At one stage, Twainese bicyles were shipped to USA, then reshipped to
Australia,
 
T

tuppy

Jan 1, 1970
0
I have had many years life with these 24v ac solenoids (daily
watering). I deliberately ran one off a 12vdc solar irrigation
project knowing that eventually the core would polarise and solenoid
wont pull in properly. Those $18 24 ac solenoids lasted 2 years
before failing on DC. I replaced the solenoid with another but this
time I reverse the leads every couple of months or so. Been about two
years on DC no failure yet. I did plan to buy a cheap mini car
inverter and run a 240/24v xformer to feed solenoids AC in future
anyway.
 
Top