Time Lapse Circuit

How is a circuit for time lapse of five hours periodic time that automatically goes off and and lapse the same periodic time automatically on, designed? For a 18.5 v, 3.5 A and 65W.

If you are looking for a one-off unit, use an Arduino with a DC motor shield that can drive 3.5A. The software is very simple for your application.

If you are looking to make lots of them, use an ATTINY with a MOSFET or an IXYS solid state relay like the CPC1709 which provides optical isolation between the circuit and the load.

This all assumes you are switching a DC circuit that is not highly inductive (no motors, coils). If the load is inductive write another note with more details and you will get guidance.

Thanks Frank I will get back to you before the week ends.

Have you looked at a zelio smart relay? Not as cheap but lots of applications and simple.