Voltage switch circuit

[batman45]

Hi, I was wondering how I could make a voltage switch that would allow electricity to pass if it sensed 3v.

 

[davenn]

Hi Batman45
welcome

OK
pretty easy to do
give us some more background, particularly where the 3 volts is coming from ??

Dave

 

[batman45]

There would be a 5 v power supply charging a bank of batteries rated for 3v. Once the switch detects 3v in the charging batteries, it will allow a resistor to decimate the rest of the batteries voltage. Basically, the switch will detect 3v and will allow current to flow through.

 

[batman45]

The switch would allow a current to flow through if a bank of batteries charged up to 3v

 

[batman45]

Like a voltage transistor?

 

[rich-38]

I think he means something with a 3.3 zener and if one of the batteries comes below that voltage, it automatic start charging the batteries with the 5v . Which will be regulated, but i don't know which kind of batteries there are and if he wants it measured per battery. Enough ways to make it, but i would simply by the load ic, since li-ion or stuff like that , doesn't like high currents. Still i don't know what he wants Vcc is 5v and accu's have to load reaching 3 Volts

 

[davenn]

There would be a 5 v power supply charging a bank of batteries rated for 3v. Once the switch detects 3v in the charging batteries, it will allow a resistor to decimate the rest of the batteries voltage. Basically, the switch will detect 3v and will allow current to flow through.

if you have 5V going to the batteries, you are never going to see a 3V situation as there will always be 5V there

Dave

 

[BobK]

It's worse than that. If you put 5V, without limiting current on a 3V battery you will likely start a fire. Charging batteries is complicated and should be left to those with some knowledge.

Bob