Automatic Switching


Thread Starter


My application is a fairly small EFI system. I need to power on start-up from a Li-Ion batter pack then switch the power draw to an engine generator.

How would I switch between the two sources automatically? I'm also obviously trying to avoid as much drop-off as possible.
What is the voltage of the Li-Ion battery? What is the voltage of the engine generator? (12 to 14V)
Is the problem you don't have enough power for the EFI while the starter cranks?

Two diodes, one from the Li-Ion battery and one from the engine, The EFI will live on which is higher.

EFI= electronic fuel injection system
you can see this project very help full. buck converter steps down the input voltage while it increases the output current. a DC to DC buck converter that can be used effectively as a switching power supply.
Late, but you could use the normally open and normally closed contacts of a relay

NC: connect to the battery (So this is the default option for starting)

NO: connect to the generator

At the moment you want to toggle the supply , command the relay to toggle contacts.