GARDENA T14e control signal

[dubovanszky]

Automatically watering garden GARDENA T14e control signal - solenoid valve

GARDENA T14e control signal - signal to solenoid valve - automatic watering

I would like watering with much more flexibility than 3 minutes in every 6 hours. I would like to water 20 minutes every hours in the night for 6 hours.
I have tested the GARDENA T14e Water Timer valve and I found out the signal I can switch it on and off.
The valve is moved by a solenoid. You can see the schematic figure on the back side of the box of the GARDENA T14e. View attachment 65426
DC resistance of the solenoid valve: 38 Ohm. (38 Ω)
I have used 500 mA AC-CD adapter
Input 230 V AC, output 4,5 V (or 3,0 V) and 1,5 V DC.

To open the valve
switched to 4,5 V (or 3,0 V) position and connected + to central point of the valve RCA connector and - to the outer surface of the RCA connector. + o ) -
You need this signal only like on impulse. After the impulse the vale stays open without the signal because it works with a solenoid.
When I used lower voltage the valve was not opened.

To close the valve
switched to 1,5 V and connected - to central point of the valve RCA connector and + to the outer surface of the RCA connector. - o ) +
You need this signal only like on impulse. After the impulse the vale stays closed without the signal because it works with a solenoid.
When I used higher voltage then the valve was not closed.

I hope my comment helps to find the control signal of this solenoid valve.
View attachment 65390
Good luck for you!

 

[alec_t]

1) Can you confirm you have removed all the timing electronics from the valve and were just testing the valve?
2) We know 4.5VDC can open the valve, but does it stay open if you then simply remove the 4.5V?
3) Is 1.5VDC enough to open the valve?
4) What is the DC resistance of the valve?
5) Is the valve moved by a solenoid (quick-acting) or by a geared motor (slower-acting)?

 

[dubovanszky]

Automatically watering garden GARDENA T14e control signal - solenoid valve

1) Can you confirm you have removed all the timing electronics from the valve and were just testing the valve?
Answer: Yes, I have removed controlling computer panel as you can see it on the picture.

2) We know 4.5VDC can open the valve, but does it stay open if you then simply remove the 4.5V?
Answer: Yes, it stays open after I remove 4,5 V, because the solenoid technology.
You can see the figure about the construction on the back side of the box of the GANDENA T14e.

3) Is 1.5VDC enough to open the valve?
Answer: Yes, it is, and I I use the AC-DC adapter and switch to more than 1,5 V, then it will not switch the valve off. So it the voltage it more, then it does not works!

4) What is the DC resistance of the valve?
Answer: 38 Ohm. (38 Ω)

5) Is the valve moved by a solenoid (quick-acting) or by a geared motor (slower-acting)?
Answer: The valve is moved by a solenoid. You can see the schematic figure on the back side of the box of the GARDENA T14e.

 

[alec_t]

You can see the schematic figure on the back side of the box of the GARDENA T14e.

I can't. I don't have the box . If you could post the schematic that might give us some help.

3) Is 1.5VDC enough to open the valve? Answer: Yes, it is,

Then 1.5V would open the valve and reversing the polarity of the 1.5V would close the valve. An H-bridge circuit could do that.

 

[dubovanszky]

Automatically watering garden GARDENA T14e control signal - solenoid valve

Question: I can't. I don't have the box . If you could post the schematic that might give us some help.

Answer: Picture uploaded into my first post..

Picture is here.

Your next question was:

Question: Then 1.5V would open the valve and reversing the polarity of the 1.5V would close the valve. An H-bridge circuit could do that.

Answer: In 3,0, or 4,5 V position or more, on AC-DC adapter the valve is opening, but in 1,5 V the valve is not opened.
In 1,5 V position of the AC-DC adapter the valve is closing, but if I put into 3 V or more V positions the valve is not closed.

 

[alec_t]

Right. So we need a circuit which switches between 4.5V one way, off, and 1.5V the other way. I'll have a think about that, but I'm going to be off-line for a few days. As for the timing, can you use a conventional 'segment timer' ? That would give you on/off control at 15 min resolution.

 

[dubovanszky]

Automatically watering garden GARDENA T14e control signal - solenoid valve

Right. So we need a circuit which switches between 4.5V one way, off, and 1.5V the other way. I'll have a think about that, but I'm going to be off-line for a few days. As for the timing, can you use a conventional 'segment timer' ? That would give you on/off control at 15 min resolution.

Dear Alec,
So I need 2 timers, two AC-DC adapters?

If I give 4,5 V and 1,5 V for this solenoid for 15 minutes than it can broke it, not?
The idea is to give 4,5V impulse to open the valve only when the pump get 230 V and starts to work.
Before pump stops to work give 1,5 V to close the valve.
With this process the pressure will not gone away while the pump is not working.
Other way I noticed, the pressure goes as low that the pump cannot take again the water from the fountain.
Best Regards, Zsolt

 

[alec_t]

I would like to water 20 minutes every hours in the night for 6 hours.

Would 15 minutes every hour be enough? If so, then a segment timer could be used to time each 15 minute period and a circuit would be needed to time only a ~1 sec 4.5V 'on' pulse at the start of each 15 min period and a ~1 sec 1.5V 'off' pulse at the end of each 15 min period. I have designed a circuit which should do that. But if 15 mins is not enough then a segment timer would not be suitable and the circuit would also have to time 15 min, 1 hour and 6 hour periods, making it more complicated.
Only one AC/DC adapter would be needed for either solution.
You now mention closing the valve before the pump stops. If you want to control the pump automatically and link that control to control of the valve then the whole project becomes complex enough to justify using a microcontroller to handle all the timing and will also require mains-rated heavy-duty switching circuitry.

 

[bargy]

Hello,

Both attachments (pictures) are not working. Can you please re-upload?
Thanks!

 

[Inquisitive]

This is the message I get when trying to view attachments.

"
Electronics Forum (Circuits, Projects and Microcontrollers) - Error
This attachment cannot be shown at this time. Please try back later. "

Sorry for the bold text. It was copied from the forum verbatim.

 

[JimB]

The attachments were probably lost during a server crash a year or so ago.

Unless Dubovanszky is reading the forum, which is unlikely as he was last seen here in August 2012, the probability of reloading the attachments is zero.

JimB