N00b - I need a 12v timer relay that triggers for 10 min every hour.

Im not really the Arduino builder type but I cant find what I need elsewhere (or they dont understand what I am asking). I have a 12VDC hot water recirc. system that I am building. I need to trigger the pump to run for 10 min every hour. Power is currently being supplied by a 12V battery but very soon will be powered by a solar charge controller so it only runs during the daylight hours.

I need something that has the ability to be manually updated for winter vs. summer use as it will need to run for longer periods in the winter.

Any help or links would be welcomed, and I am sorry if I didnt put this in the correct location.

So, you are asking us to guess that your solar charger will provide enough power to start and run the pump for 10 minutes?

Paul

Paul_KD7HB: So, you are asking us to guess that your solar charger will provide enough power to start and run the pump for 10 minutes?

Paul

In my opinion that is the least of the problems, the way the original post is worded "Power is currently being supplied by a 12V battery but very soon will be powered by a solar charge controller so it only runs during the daylight hours." implies there will no longer be a battery in the system and "I need something that has the ability to be manually updated for winter vs. summer use as it will need to run for longer periods in the winter." suggests the OP doesn't understand how solar PV works.

I would like to know how the water is being heated? Why the recirc pump isn't controlled by a thermostat? What the pump power/current draw is?

Arduino can easily do the job although so can a 12vdc timer. With the Arduino it would be easy to add a switch that selects summer or winter times or add a Real time Clock and set seasonal settings by date.

A simple relay timer could look like this (for UNO, Nano) but we need much more info, wiring diagram, part numbers, detailed description of your system, etc. Also, Arduino timer will drift over time, so you may need an RTC (Real Time Clock), they are cheap though.

unsigned long timerStart,
              interval = 30000, // 30 sec, change to 3600000 for 1 hr
              onTime = 5000; // 5 sec, change to 600000 for 10 min
const byte relayPin = 13; // onboard LED, change to your relay pin number

void setup()
{
  //Serial.begin(9600);
  pinMode(relayPin,OUTPUT);
}
void loop()
{
   digitalWrite(relayPin, millis() - timerStart < onTime);
   if(millis() - timerStart > interval)
   {
     timerStart += interval;  
   }
}

I doubt the OP will need a Real Time Clock - they make no mention of the pump running at a specific time, just that they want the pump to run for 10 minutes out of each hour and I doubt the application needs exact down to the second timing.

So just a free running one hour timer with a 10 minute on cycle should be fine and a couple of seconds drift in an hour should not be important.

There are also commercial off the shelf interval timers that do what you want, used a couple many years ago but sorry forgot the company name, they made litertally hundreds of different versions

saildude: So just a free running one hour timer with a 10 minute on cycle should be fine and a couple of seconds drift in an hour should not be important.

Correct.

On all the other notes I mis-stated when I said it would be the solar charge controller running it solely. It will still be attached to a 12v battery.

I am not building this myself, JCA34F, I am ideally just looking for guidance on a board that will do exactly what @Saildude said.

Water is being heated through a Pex tube system in an enclosed insulated box. It is routed from my current Hot water heater through this box and back into the hot water heater. I am using a SeaFlo 42 12v pump. I will eventually be adding a Thermostatic switch but havent figured everything out yet.

Without a heat exchanger, I hope you have lots of chlorine in the water.

Paul