Digital timer disagrees with inverter

[simonom]

Good day all, i am trying to run an aquarium pump for 5 minutes every hour during daylight hours. I have a Krieger KRU1100 modified sine wave 12v- 240V inverter providing the power to the pump.
A mechanical timer drifts due to frequency issues (discussed in another thread) and all the ones i can find are minimum 15minutes interval on/off.
I have tried many digital timers but they all get fried at the resistor shown in the attached diagram (about 100-150ohm) when using this inverter.

I'm guessing it's a cheap timer/relay circuit that doesn't respond well to the modified sine wave, voltage input or frequency from the inverter. What can i do to get this working on a digital timer? Or any other options?

TIA!

 

[Mattb4]

I think your answer is in your question. You need a pure sine wave inverter. I run a couple of digital timers off my PSW AIO and they work without a problem.

 

[simonom]

Thanks, guess your right, i'd like to make the best out of the inverter i have if there's another way though

 

[Crowz]

I use these :

https://www.amazon.com/gp/product/B07CVPKD8Z/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

to do exactly what your trying to do. I have multiple 55 gallon tanks and I control pumps, lights etc with a few of the above units. Never had issue with the timer part or remote controlling them with the phone either. The timer can't really drift since its synced to the internet and it hasn't had an issue with the pumps either.

These are what I'm switching over to now since it works with the emporia app I'm using to monitor the house. The first one I linked had energy monitoring but they dropped that feature on the new ones. My current ones have the feature.

https://www.amazon.com/gp/product/B08CVR55FY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[MrM1]

I use these :

https://www.amazon.com/gp/product/B07CVPKD8Z/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

to do exactly what your trying to do. I have multiple 55 gallon tanks and I control pumps, lights etc with a few of the above units. Never had issue with the timer part or remote controlling them with the phone either. The timer can't really drift since its synced to the internet and it hasn't had an issue with the pumps either.

These are what I'm switching over to now since it works with the emporia app I'm using to monitor the house. The first one I linked had energy monitoring but they dropped that feature on the new ones. My current ones have the feature.

https://www.amazon.com/gp/product/B08CVR55FY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

This

Or look into TP Links Kasa Line of Smart Home Devices