Hello. I would like to get 3V and 4.5V from 3 AA batteries. Is the below diagram correct? Batteries Diagram The two devices do not have the same consumption. It does not matter what device will stop working first. Thank you.
Im not the best guy to answer but if your 3V device is drawing power you wont get the 4.5v out on the other end.
You could step down the 4.5v with a voltage regulator or with some resistors but thats not the best way.
Why not? If the battery has sufficient mAH capacity, there is no reason the 3V wouldn’t hold 3V.
Why not? If the battery has sufficient mAH capacity, there is no reason the 3V wouldn't hold 3V.
The 3V isnt the problem its the 4.5v that he needs as well and that will drop if theres a load on the first two batterys, I know the drop depends on the current draw of the first device so it all probably depends on what he wants to power.
The real problem is that you will drain the cells unequally, which is wasteful. If using rechargables you risk damaging them and severely reducing lifetime through unequal use and equal re-charge.
What do you want the two voltages for? Would a 3.3V regulator or DC-DC converter not be a better approach?
That setup should work, with a couple of caveats.
The 2 batteries in both circuits will be drained faster than the third, since the third is only handling the load from one device, but the other two are providing the sum of the current used by both devices.
If using rechargables, you have to use a charger that doesn't charge the batteries in series.
There are usually better ways to achieve something like that - but for a simple and expedient solution, it'll work.
Undermentioned: The 3V isnt the problem its the 4.5v that he needs as well and that will drop if theres a load on the first two batterys,
No that is not correct. A battery does not drop voltage on load unless the load is close to the limit of what the battery can supply. Just like CrossRoads said.