There was already a review about this timer (https://redlightgreen.org/blog/aliexpress/30754.html).
I will just add the dissection and other interesting details.
Inquisitive and fans dopilivaniya improvements please under.
To begin with, I got a defective timer. The electronic part is working fine, but the valve itself passes water without turning on the power.
I shot a video (see here) and sent it to the seller. He began to kick. I opened a dispute.
The seller offered a refund of as much as $ 2. I intensified the dispute and repulsed $ 10.
After that, I decided to autopsy, but where to go :)).
But before that, I, in search of additional. timer information, stumbled upon a website www.mastercity.ru/where a UV comrade from Moscow disassembled and described the operation of a timer. with a membrane valve. But he did not describe the disassembly process.
And here is a secret. I searched for it for a long time, but found it. It is necessary to lift the glued film near the small hole
At first I thought it was just a latch, but no. A screw was found under the film. He turned it away and the timer board calmly pulled out of the case
Under the board there is a membrane opening / closing mechanism
He, too, cannot be pulled out from the start. 3 screws turn out easily, and the 4th just under the engine gear. I had to tinker while I picked up a screwdriver and carefully, so as not to damage the gear, turned the screw. Took out the mechanism
, and below it is a membrane that opens the passage of water.
Between the membrane and the mechanism is a spring.
This detail is the main cause of all ills. (Water transmission or vice versa not transmission even with good pressure). The hardworking Chinese set the wrong spring that caused my troubles.
My spring did not press the membrane and water at allwent directly. I had to pick up 2 small washers and put them under the spring. 10 times I had to remove and set the mechanism until I picked it up so that the membrane would open at a column height of 1.6 meters
When set properly, the membrane should openat 1.5 - 1.8 meters of column water. That is 0.15 - 0.18 kg / cm2. This shows that a timer with such a valve can be used by gravity ... The principle of operation of a membrane valve is quite sophisticated.
Here is document, with a complete and understandable description. The principle of the membrane valve. The only difference from our valve is that it uses e-mail. magnetic drive, and we have a motor.
We dealt with the mechanics, now the electronic part of the valve.
Everything is fine and beautiful here.
The only negative is that the screen is connected to the board through an elastic band.
I don’t want to be a copy pasteur, so I give a link pages of the aforementioned comrade. It will be especially interesting to drip irrigators.
I also learned a lot of interesting things there. For example, the fact that a voltage pulse lasting 1.5 seconds is supplied to the motor. But it changes polarity when open / close. This pulse can be used to control external mechanisms.
For example, a pump or add. valve. By the way, I need to turn on the water pump (12V). About her, I hope there will be enough time for a separate review.
I already have an idea how to implement this, but I would like readers
shared their ideas in this regard.
That's all. I hope my information will help to solve problems with the valve.