The presented water flow controller circuit making use of a valve timer circuit could be applied through the use of an easy two stage programmable timer design, as proven in the above diagram.
We now have already talked about this programmable timer circuit in one of my prior content. The equivalent concept has become employed in this design too.
Speaking about the diagram above you can easliy see two similar timer levels making use of the ICs 4060 which are put together with each other such that when the upper module stops counting, the lower gets turned on and the range proceeds extremely from the upper timer to the lower and back to the upper timer module.
The functioning of the system could be realized as discussed below:
When power is activated, the circuit will remain disabled since pin12 of the upper IC has little or no access to a ground for initiating the counting practice.
On the other hand the moment water is introduced across the shown "water sensing points" the pin12 of the upper IC experiences a ground potential by way of these sensing conductors and promptly begins the counting process.
The initialization commences with a low at pin3 of the upper IC, the red LED now lights up suggesting the start of the counting method by the system.
After approximately 2 minutes which might be set by correctly adjusting P1, C1, the upper IC finishes its counting reverting its pin3 with a high logic, which quickly activates the relay by way of the associated BC547 driver stage. The relay clicks energizing the water valve mechanism into action.
The green LED all together lights up recognizing the above activation of the relay and the valve.
The high from pin3 of the upper IC as well assures that the IC latches itself and stops counting for the moment, this is exactly applied by the diode that's attached across pin3 and pin11 of the upper IC.
The above talked about high from the pin3 of the upper IC all together triggers the lower BC547 into conduction which will grounds the pin12 of the lower IC, confirming a activating signal to the lower IC.
The lower IC now starts out counting until 8 minutes have lapsed, this time period could be correctly set by adjusting P2/C2 of the module. When this set period elapses the pin3 of the lower IC goes high, "kicking" a activating pulse to pin12 of the upper IC, which reacts to this and quickly resets the upper IC into its original status in order that it commences counting its established 2 minute slot.
The above method switches OFF the relay and the valve mechanism delivering a free route for the water to flow again, for until 2 minutes have passed and the cycle repeats, but only on condition that the water sensing points remain subjected to a water content.