I have a 3.7v lipo rechargeable battery and need to get at least 3.5v to power a display.
But the battery should be 4.2v at its peak and 3.0v when its empty. How can i boost this voltage slightly without using a boost converter. I need this project to be really small. And would like to create my own boost converter instead of using a ready to use one. I only need to stay around 3.7v at all times.
How can i boost this voltage slightly without using a boost converter.
If you had any system that worked woudn't you call it a boost converter?
Well yes, but i mean i don't want to use a ready to use boost convert but want to create a diy one. Which only boosts it slightly up instead of a variable one.
dennis_arduinouser:
How can i boost this voltage slightly without using a boost converter.
I guess you can start by re-writing the laws of physics. It might help by defining "really small". The capacity of a battery, i.e. its ability to stay above 3.5v, is essentially commensurate with its volume, but you may find you can get closer to what you want with a more suitable shape.
but want to create a diy one
Well that is quite difficult and requires skill that you probably haven't acquired yet. I have managed specialist power supply engineers in many projects and I have yet to meet one that can do a fully working design first time.
Which only boosts it slightly up.
No you want a buck / boost system because as you said:-
But the battery should be 4.2v at its peak and 3.0v when its empty.
Nick_Pyner:
How can i boost this voltage slightly without using a boost converter.
So your asking how you can boost a voltage (slightly) without boosting it ?
You can buy a wide range of voltage converters from Pololu, including step-up/step-down regulators, which do what you want.
This one will operate on a voltage in the range 2.5-11.8V and output a voltage in the range of 2.5 - 8V.
Of course you know that an undervoltage shutoff is required, as LiPo cells are destroyed by discharging to below about 2.8V.
You could just ... not. By the time a 4.2V Li-ion cell reaches 3.5V, it only has about 1/4 of its energy left usable (ie 75% of the energy comes from the 4.2-3.5V range, and 25% from 3.5 to 3.) Throw in a slightly larger cell if you need more runtime. (the battery will last a lot more cycles if only discharged to 3.5V, too.)
dennis_arduinouser:
I have a 3.7v lipo rechargeable battery and need to get at least 3.5v to power a display.
But the battery should be 4.2v at its peak and 3.0v when its empty. How can i boost this voltage slightly without using a boost converter. I need this project to be really small. And would like to create my own boost converter instead of using a ready to use one. I only need to stay around 3.7v at all times.
You first indicated that you want to boost a voltage without using a boost circuit. And then you're saying you want to create a boost converter. The art of fighting without fighting?
Hi,
How much current?
What is the application?
Thanks.. Tom...
Some info for you to read
Design tips for an efficient non-inverting buck-boost converter
Design Calculations for Buck-Boost Converters
Buck-Boost Converters