Do you guys know any component that switches from a battery source to grid power if it falls below a certain voltage?
Im doing a project that has something to do with solar panels. I need a constant 5v source to power a component and I need a switch that closes and changes to grid power when the battery runs out.

Any helps would be greatly appreciated!

 

A comparator with hysterisis, explained here:

http://www.analog.com/library/analogDialogue/archives/34-07/comparators/index.html

 

Perhaps you could use diodes?

 

Please clarify what you mean by "power grid." If you mean the AC power coming out of the wall, this is not a trivial task, and involves dangerous high voltages if you want to build everything yourself.

ak

 

If you have +5VDC from two sources, a battery and a mains powered power supply, then diodes can be used to select the source with the higher input voltage.

Your question was a bit unclear since you mentioned solar panels and some people want to feed the power grid from their solar panels. This is the complicated problem mentioned by AnalogKid.

 

How much current does the load require?
How much current does the solar panel produce?
What is the battery chemistry? (the cut-out voltage must be set to protect the battery from being over-discharged.)

There should be a higher cut-in voltage (hysteresis) to allow the battery to accumulate charge before it picks up the load the next day.

 

Do you guys know any component that switches from a battery source to grid power if it falls below a certain voltage?
Im doing a project that has something to do with solar panels. I need a constant 5v source to power a component and I need a switch that closes and changes to grid power when the battery runs out.

Any helps would be greatly appreciated!

Your inquiry is ambiguous...

If you are referring to the transfer switch itself, be advised that it must be configured as a feed - selector -- lest you risk 'phase clashing' (a 'contest' you just can't win!!! )

If, on the other hand, your reference is to DC power or DC control signals, "diode OR-ing" (as described elsewhere on this thread) is satisfactory provided that, in the case of DC power, the current is such that dissipative losses are tolerable...

Best regards
HP