This circuit is set up for a fully automated transfer of mains power to a generator! It includes a 5 second delay before 3 attempts of 3 seconds running the starter motor with a pause of about 5 secs each time to start the generator
The switche on the left side are to simulate power interruption and restoration.
The grid mains is represented by the upper power source and the auxillliary supply by the lower power source.
Normal operation is with upper swtch closed and the lower one open. The relay next to the battery, on the right, is energised a therefore the battery is being trickle charged.
Opening the upper switch simulates grid supply failure. This causes the relay to de-energise this then applies 12v to the two NE555 timers. The lefthand timer single shot period lasting about 40 secs and supplies the reset to the righthand timer.
After an a delay of 5 secs the attached relay is enegised, power is applied to the starter motor and after 5 secs the relay de-energises.
This above repeats as long as the first timer allows, which is 3 times.
The lower switch simulates the aux power coming on line and when this happens the battery relay re-energises to ensure the battery is recharged.
