Hi everyone,
I'm working on my first ever circuit and PCB board for an automatic watering project that requires a long on/off time delay relay controller. I could really use some guidance from this knowledgeable community.
Project Overview:
I know I haven't explained everything in detail, but I plan to make a follow-up comment with my thought process behind each part of the circuitry so you can understand what I'm trying to achieve.
Best regards,
Nik
![Screenshot_20240525_195317.png Screenshot_20240525_195317.png](https://forum.allaboutcircuits.com/data/attachments/310/310781-41307959122ba6bf1956253b52bc86d6.jpg)
![Screenshot_20240525_195447.png Screenshot_20240525_195447.png](https://forum.allaboutcircuits.com/data/attachments/310/310782-a087f36175e1c6a3a50b76b10f460047.jpg)
![1716659801857.jpg 1716659801857.jpg](https://forum.allaboutcircuits.com/data/attachments/310/310784-02712c86b57255459313322cd1082547.jpg)
I'm working on my first ever circuit and PCB board for an automatic watering project that requires a long on/off time delay relay controller. I could really use some guidance from this knowledgeable community.
Project Overview:
- Objective: To design an on/off timer circuit that can manage long on/off time delays.
- Requirements:
- On Time: Separately adjustable from the off time. Currently, I'm planning to set a frequency and use a binary ripple counter (CD4060) to divide it, effectively making the frequency much lower.
- Off Time: Same approach as ON time.
- Load: Capable of switching various voltages/currents. The relay will likely support 12V or the electric grid (230V in my case).
- Accuracy: High accuracy isn't crucial, but I would like it to be repeatable. For instance, if I want an off delay of about 12 hours, I can set the approximate frequency required and select the correct output on the counter to divide it accordingly. A slight deviation of a few minutes is acceptable.
- Interface: I plan to use an Excel sheet with pre-calculated capacitor/resistor values for certain frequencies. Would it be beneficial to use a potentiometer on the frequency circuit for fine adjustment?
- Parts on Hand: I want to use the components I already have: NE555P, CD4060, 1/4W and 1/8W resistors, ceramic capacitors, transistors, etc. (I'll attach a photo of the labels on my component drawer. I have these parts because I enjoy fixing circuits with obviously broken/burned components.)
- Avoiding Microcontrollers: I'd like to make this circuit without any microcontrollers, even though I know it would have been faster and easier.
- Inexperience with Components: I have not used transistors or counters before, so I'm unsure if my current design would work. I haven't added any resistors to the transistors yet, but I know they are needed and plan to do so.
- Resetting the Counter: I assume that directly connecting the output of my counter to itself to reset its count might cause issues and uncertainty. How would you go about fixing this? Should I use some sort of delay or an additional IC?
I know I haven't explained everything in detail, but I plan to make a follow-up comment with my thought process behind each part of the circuitry so you can understand what I'm trying to achieve.
Best regards,
Nik
![Screenshot_20240525_195317.png Screenshot_20240525_195317.png](https://forum.allaboutcircuits.com/data/attachments/310/310781-41307959122ba6bf1956253b52bc86d6.jpg)
![Screenshot_20240525_195447.png Screenshot_20240525_195447.png](https://forum.allaboutcircuits.com/data/attachments/310/310782-a087f36175e1c6a3a50b76b10f460047.jpg)
![1716659801857.jpg 1716659801857.jpg](https://forum.allaboutcircuits.com/data/attachments/310/310784-02712c86b57255459313322cd1082547.jpg)