I need to create a programmable timer circuit to activate a 120 volt receptical

I’m not sure if this is the right category for my question. Please advise if it isn’t. Thanks!

I want to create a programmable circuit to energize a 120 receptacle for charging an electric car. I have an off grid power system with the charge controller in diversion mode. So, when the batteries are full, the controller begins to dump power to the heat strip dump load. This is in PWM starting at a very low voltage. I would like a programmable timer circuit (dip switches), so that an initial voltage 0-60 volts dc would trip the circuit for a given amount of time in minutes. The power system is 48 volts DC, so the 60 volts would allow the timer to handle the power (if the electric car was fully charged and the only place for the power to go was the dump load. I’m not exactly sure how high the voltage might go to the dump load.

The timer circuit would trip another relay to energize the 120 volt receptacle that the charging cord is plugged into. The car would only be charged when there is excess power in the system. The timer circuit would allow the car to charge until the programmed timer quit. Then, if power was still available, it would begin again.

Perhaps there is a better way to do this. A timer circuit with dig switches is available as a kit, and perhaps I have used this in the past. Any other suggestions about how to design this circuit and what components are available would be appreciated.

Thanks!

paul chew

Hi @coweeta this is not as simple as charging a 12V car battery…

Take a look at: https://www.openevse.com/ for example…

Regards,