It sounds like you're doing very well on your own. This weekend is a bit busy, but I'll get back into this thread by Monday. Where are you located?

ak

I live in Adelaide Australia ak. https://en.m.wikipedia.org/wiki/Adelaide

 

I appreciate you might want to hone your electronic skills, but irrigation timers with relay out put are dime a dozen here, not only a real time clock but sequential operation.
Max.

 

What voltage of relay that you should use, normally if the Vcc is 12V then you can pick up the 12V relay, if the Vcc is 5V then you can pick up the 5V relay, if you know more about the current of components then you can using it quite easy, as you can using a 5V relay in a 12V circuit, the first you have to know the current of relay and you could calculate the current limiting resistor to limits the current to flows through the coil of relay to suit the relay needed and then the 5V relay will be survive in the 12V circuit, but you can't using a 12V relay in a 5V circuit, because the current will be not enough to drive the coil of relay, unless the you have a boost circuit to raising the voltage and providing enough current for the circuit and relay.

 

I appreciate you might want to hone your electronic skills, but irrigation timers with relay out put are dime a dozen here, not only a real time clock but sequential operation.
Max.

Thanks for your reply max.

Do u mean irrigation controllers on the retail market? If so then I can't find anything that will do what I want. I have looked and looked and looked.

In any case as you've mentioned, this is a learning exercise primarily.

Mellisa

 

What voltage of relay that you should use, normally if the Vcc is 12V then you can pick up the 12V relay, if the Vcc is 5V then you can pick up the 5V relay, if you know more about the current of components then you can using it quite easy, as you can using a 5V relay in a 12V circuit, the first you have to know the current of relay and you could calculate the current limiting resistor to limits the current to flows through the coil of relay to suit the relay needed and then the 5V relay will be survive in the 12V circuit, but you can't using a 12V relay in a 5V circuit, because the current will be not enough to drive the coil of relay, unless the you have a boost circuit to raising the voltage and providing enough current for the circuit and relay.

Thanks for that clarification scottwang. I take your point. It is a 5v relay and it does everything I want it too. It's current is I think within the range of the transistor amplifier that #12 and AK have in mind to bookend their switching and timing circuitry
MK

 

Using the resistance method for DC solenoids is valid, but of no use for AC type as the current is limited by the Inductive Reluctance.
Max.

Max I was referring in that post to the dc relay coil not the solenoid valve. The arithmetic regarding ohms law seemingly worked out pretty well so maybe the impedance of the relay coil is not the same issue as the one you describe.
Mel

 

Typically all AC relays and solenoids are going to measure lower than their DC counterparts.
It is possible to burn out a AC device when you run it on the same voltage value using DC.
If you were measuring a DC coil then the Ohms law reading is valid.
Max.

 

I live in Adelaide Australia ak. https://en.m.wikipedia.org/wiki/Adelaide

Look up these three parts and see what you think:
Oscillator/divider: CD4060B
Counter: CD4017B
Relay driver: ULN2003

With these parts you can have 1 to 7 outputs that step through at a constant rate. At the end of a cycle it can repeat or halt. With one of those little twp-pin shunts and a 2x7 header you can select how many steps are in a cycle without any wiring changes.

Don't let the 4060 scare you. It actually is more simple than a 555. In the standard astable configuration, a 555 has 8 pins that are connected to something. For the 4060 to do the same thing, there are only 7 pin connections. Plus, the timing capacitor is 16,000 times smaller.

ak

 

Look up these three parts and see what you think:
Oscillator/divider: CD4060B
Counter: CD4017B
Relay driver: ULN2003

With these parts you can have 1 to 7 outputs that step through at a constant rate. At the end of a cycle it can repeat or halt. With one of those little twp-pin shunts and a 2x7 header you can select how many steps are in a cycle without any wiring changes.

Don't let the 4060 scare you. It actually is more simple than a 555. In the standard astable configuration, a 555 has 8 pins that are connected to something. For the 4060 to do the same thing, there are only 7 pin connections. Plus, the timing capacitor is 16,000 times smaller.

ak

Ok thanks for the start AK. I will read up on them

 

hello dendad,
i really appreciate your interest in my post and especially the fact you went to the trouble to write such a detailed and helpful reply.

you copped a bit of flak for mentioning arduino in this forum. dont worry about the purists! hehe.

i would like to learn arduino but i want to do the hard yards learning about solid state electronics first by using transistors and resistors and diodes and capacitors. previous responders to my posts have indicated i can achieve what i currently want to do with this component based circuitry. if not i will be on your doorstep.

i have been thinking about some other uses for arduino or something similar that has a whole computer in it. this includes some home automation and some web based remote control applications but they are only a dream at the moment. i need to crawl before i can run and i am likely to get much more satisfaction from working with an embedded computer like arduino if i have some electronics knowledge to beging with.

thanks again and best wishes

mellisa king

Thank you for the kind replay Mellisa.
I too am in Oz, about 2 hours North of Melbourne.
About 30 years ago I made a hamburger flipper timer that had individual times set for each step and will try to remember how I did it.
Something like a variable resistor or Potentiometer (pot) fed from each output used for the relay drive, so at each step the time delay is adjustable.
I can't quite remember if it was the favorite of this site, The Dreaded 555 Timer that I used or what, then it was fed into a 4017 counter/divider I think, and the output after the last relay was used to reset it all. So to add more relays, you just need to move the reset link to the next output and add the FET relay driver or optocoupler or whatever other output configuration you are using, along with the pot to set the time delay. This way you could have a max of 10 relays, all adjustable.
The pot outputs are connected to the 555 via diodes so they do not interact with each other.

I'll try later today to figure out the circuit if you want that level of help
Oh, it maybe mentioned elsewhere, but if you are going to drive water solenoids, use 12VAC or 24VAC ones, and a power transformer. Do NOT use 240VAC ones as that involved dangerous volts. Also, do nor use DC solenoids as that can encourage electrolysis. The local big hardware stores have them. And you can switch them with Solid State relays to give isolation, or just mechanical relays if you prefer.

 

I can't quite remember if it was the favorite of this site, The Dreaded

By "this site" did you mean aac? I went here after googling 555 and this seems an amazingly informative and well written article on it. Wld u recommend I use this article to learn abt 555?

httpshttps://www.google.com.au/amp/www.instructables.com/id/555-Timer/%3Famp_page%3Dtrue

 

Thank you for the kind replay Mellisa.
I too am in Oz, about 2 hours North of Melbourne.
About 30 years ago I made a hamburger flipper timer that had individual times set for each step and will try to remember how I did it.
Something like a variable resistor or Potentiometer (pot) fed from each output used for the relay drive, so at each step the time delay is adjustable.
I can't quite remember if it was the favorite of this site, The Dreaded 555 Timer that I used or what, then it was fed into a 4017 counter/divider I think, and the output after the last relay was used to reset it all. So to add more relays, you just need to move the reset link to the next output and add the FET relay driver or optocoupler or whatever other output configuration you are using, along with the pot to set the time delay. This way you could have a max of 10 relays, all adjustable.
The pot outputs are connected to the 555 via diodes so they do not interact with each other.

I'll try later today to figure out the circuit if you want that level of help
Oh, it maybe mentioned elsewhere, but if you are going to drive water solenoids, use 12VAC or 24VAC ones, and a power transformer. Do NOT use 240VAC ones as that involved dangerous volts. Also, do nor use DC solenoids as that can encourage electrolysis. The local big hardware stores have them. And you can switch them with Solid State relays to give isolation, or just mechanical relays if you prefer.

You said: "individual times set for each step and will try to remember how I did it"
-- that would be awesome pls. I was asked in an earlier post from analogue kid if I wanted this adjustability and my response was no cos I wanted to simplify in order to get started.... But.... It wld be awesome. I can see it wld be great future feature if eg I wanted to combine my vegie watering with say lawn watering and pot plant watering both of which wld require vastly different timing due to their size of earth to be watered.

Btw, on this topic of future expansion and flexibility I take yr earlier point abt the Arduino option. However, if I go down this "componentry path" that i am insisting on - instead of an imbedded computer - i can keep building new versions of the circuit. The parts are mind bogglingly cheap and this reiterative process is the key to learning. Don't forget I am not as interest in the destination as the journey - the opposite of yr natural instincts as a consultant

You said
I'll try later today to figure out the circuit if you want that level of help

--- yes pls!

 

Look up these three parts and see what you think:
Oscillator/divider: CD4060B
Counter: CD4017B
Relay driver: ULN2003

With these parts you can have 1 to 7 outputs that step through at a constant rate. At the end of a cycle it can repeat or halt. With one of those little twp-pin shunts and a 2x7 header you can select how many steps are in a cycle without any wiring changes.

Don't let the 4060 scare you. It actually is more simple than a 555. In the standard astable configuration, a 555 has 8 pins that are connected to something. For the 4060 to do the same thing, there are only 7 pin connections. Plus, the timing capacitor is 16,000 times smaller.

ak

I have to go off line now AK. Thx again for these three leads. I will be able to re engage tonight and I will give u feedback on yr reading suggestions sometime tmrw. Dendad is also helping pls see his correspondence.

... Dendad meet AK.
... AK meet dendad

 

First pass at the circuit. Only one relay is shown for clarity. The ULN2003 has relay coil protection diodes built-in. The whole circuit can run on anything from 5 V to 15 V, but at the higher voltages you should change the 2003 to a 2004. Moving the shunt along P1 changes the number of outputs. Never install more than one shunt.

With R2 centered, the output period will be approximately 5 minutes. You can change R1 and R2 to get different adjustment ranges. The equation is in the 4060 datasheet.

ak

 

First pass at the circuit. Only one relay is shown for clarity. The ULN2003 has relay coil protection diodes built-in. The whole circuit can run on anything from 5 V to 15 V, but at the higher voltages you should change the 2003 to a 2004. Moving the shunt along P1 changes the number of outputs. Never install more than one shunt.

With R2 centered, the output period will be approximately 5 minutes. You can change R1 and R2 to get different adjustment ranges. The equation is in the 4060 datasheet.

ak
View attachment 124831

Wow AK!!!

I am soooo grateful for this. I will get the parts right away and make it!

Thankyou. Thankyou Thankyou

Mellisa

 

AK just letting you know I looked up the three components and got some helpful downloads. I like the way the first two are often used in led light chaser circuits. And this project is going to be a slowed down version of them. Yes? It never occurred to me.

MK

 

Please reply carefully when you using quote, you already had serveral times that the replied contents and the contents of quote whom you reply to were separated, it will make the replied without contents became meaningless, I already done the megered two posts to one for you a couple times, please put your reply contents and the contents of quote together.

 

Thank you for the kind replay Mellisa.
I too am in Oz, about 2 hours North of Melbourne.
About 30 years ago I made a hamburger flipper timer that had individual times set for each step and will try to remember how I did it.
Something like a variable resistor or Potentiometer (pot) fed from each output used for the relay drive, so at each step the time delay is adjustable.
I can't quite remember if it was the favorite of this site, The Dreaded 555 Timer that I used or what, then it was fed into a 4017 counter/divider I think, and the output after the last relay was used to reset it all. So to add more relays, you just need to move the reset link to the next output and add the FET relay driver or optocoupler or whatever other output configuration you are using, along with the pot to set the time delay. This way you could have a max of 10 relays, all adjustable.
The pot outputs are connected to the 555 via diodes so they do not interact with each other.

I'll try later today to figure out the circuit if you want that level of help
Oh, it maybe mentioned elsewhere, but if you are going to drive water solenoids, use 12VAC or 24VAC ones, and a power transformer. Do NOT use 240VAC ones as that involved dangerous volts. Also, do nor use DC solenoids as that can encourage electrolysis. The local big hardware stores have them. And you can switch them with Solid State relays to give isolation, or just mechanical relays if you prefer.

Hi dendad,
AK has just devised a circuit for me.
I am committed to building it. I wld be mortified if another correspondent went to the trouble of creating one because then I wld be responsible for wasting yr time.

Before ak's came in I asked you yesterday to go ahead with yr offer to create a circuit. I am sorry but could you please hold off on that for now. It's going to take me a while to build ak's circuit.

I would still be very grateful for your ongoing help though. I just don't want you to be spending time right now on something I can't build right now.

I have been on eBay just now to source the parts and I am buying ten at a time (including 555) so I will have lots left over to build another version of the same thing for another application perhaps but more likely to learn. I don't see such a strategy as in any way a waste of my time or energy. Rather, it's an opportunity to learn which is really what my posting here is all about.

Hope yre good with this strategy dendad.

I will cc AK

Thanks millions dendad

 

Hi Analogue Kid
Out of courtesy to you and dendad I am copying in a note I just sent to him. Pls see below:

"Hi dendad,
AK has just devised a circuit for me.
I am committed to building it. I wld be mortified if another correspondent went to the trouble of creating one because then I wld be responsible for wasting yr time.

Before ak's came in I asked you yesterday to go ahead with yr offer to create a circuit. I am sorry but could you please hold off on that for now. It's going to take me a while to build ak's circuit.

I would still be very grateful for your ongoing help though. I just don't want you to be spending time right now on something I can't build right now.

I have been on eBay just now to source the parts and I am buying ten at a time (including 555) so I will have lots left over to build another version of the same thing for another application perhaps but more likely to learn. I don't see such a strategy as in any way a waste of my time or energy. Rather, it's an opportunity to learn which is really what my posting here is all about.

Hope yre good with this strategy dendad.

I will cc AK"​

I am buying parts on line. I cannot believe how cheap they are!! It's a great hobby for kids (esp. girls) and ppl on fixed incomes. Ppl like you and yr colleagues on this site are doing young ppls' interest in STEM an enourmous service. I very much appreciate your freely providing your expertise.

MK

 

Please reply carefully when you using quote, you already had serveral times that the replied contents and the contents of quote whom you reply to were separated, it will make the replied without contents became meaningless, I already done the megered two posts to one for you a couple times, please put your reply contents and the contents of quote together.

Ok thx moderator it's just my inexperience. I will try. Thx for yr forbearance