Thank you for your help on the previous occasion.
The circuit digram of the watering systom that I have posted I have built
In the power supply section the +and- 6 Volts is working ok.
The voltage at the 3 Volts DC pins is only 2.5Volts and with load the volts ar
2.5 .
I have replaced the zener diod wich is 3.6V 1W .
I also replaced the R1 200 to 2K2 Resistor.It was smoking.
Where is the problem as the zener should only allow 3.6V
I have to maintain 3V

Attached Files

Scaned watering circuit.pdf (166.4 KB, 45 views)

 

What circuit diagram?

Are you refering to a different thread? If so please post in it rather than creating a new one.

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I was able to attach the circuit digram

 

If you designed this yourself, I commend you for trying. If someone else designed it, ....
1. Your bridge is rotated 90 degrees, and is shorting out your transformer (or burning up yout bridge). I suspect it is just drawn wrong.
2. Zeners are even more inefficient than linear regulators. If you make the current-limiting resistors too large, they won't be able to supply enough current to provide regulation. If you make them too small, they and/or the zeners will either have to be physically large, or they will burn up.
3. Your 12V relay seems to be running off 6V.
4. Your electrodes don't have AC passing through them, which I'm guessing is the intent. Also, in that location, they won't provide a signal to comparator .
5. Does the 3V supply provide power to the accompanying logic?

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Ron (aka Rube)

 

A 3.6V zener diode has such poor voltage regulation that the manufacturers don't show curves for them anymore.
Look at the datasheet. The 1N4729 is 3.6V with a current of 69mA through it. With this circuit's very high 32.5VDC supply, a resistor feeding it should be 419 ohms and will dissipate 2W of heat. With the 2.2k resistor feeding it, its current is only 13mA and so its voltage might be only 3.0V, then the 3V output is about 2.3V. The zener's voltage will drop more as the BD139 transistor takes current from it. Therefore the 3.0V output will not be 3.0V regulated.

Of course the 200 ohm resistor smoked if it was small, it was heating with more than 4W.

The electrodes don't do anything. The output is the same if they are shorted or open or anything in between.

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Uncle $crooge

 

I've seen a similar circuit before on these forums but I can't remember where, can anyone else remember this?

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Screen name: Aloone_Jonez
And http://www.silicontronics.com, same screen name as here.

 

I found the same circuit in the OP's Profile, other posts.
We gave him the same answers there too.

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Uncle $crooge