In the Home assistant screen, click on Configuration on the left side
Then choose Automations
Then click on the yellow + button to add a new automation
You can skip the first screen, this is only required if you are running a voice assistant on Home
Assistant
Give your automation a name.
For the trigger set it to time pattern, this will repeat whenever the time matches your criteria. By
setting the minutes to /5 you are saying match the time whenever the minute is divisible by 5, so
every 5 minutes. If you want it every 15 minutes then make it /15.
Add a condition to only execute the automation when it meets this condition.
Choose State for the condition type.
Select your Sonoff POW from the list of Entities
After selecting you Sonoff POW you must set the state to on. Just type on in the field.
Next we must specify the action to perform. Choose Call Service for the Action type.
For the Service we will choose switch.turn_on
We must select the Sonoff POW for the entity we want to turn on
All done! Now just save the automation by clicking on the save icon