Difference between revisions of "Mcu 0137-SLA-charge-controller"

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The first version of the charge controller schematic:
 
The first version of the charge controller schematic:
  
 +
[[File:0137 schematic v1.0.png]]
  
  
  
With these objectives defined, the next steps will be to work out the following features:
 
  
* complete a rough schematic of the design (diptrace)
 
  
* voltage detection of input and output
 
  
* current detection of input and output
 
  
* auto-adjustment of boost converter output voltage from mcu
+
The next step will be to work out the following feature:
 
 
* design charge regime (boost - bulk - float)
 
  
 
* minimise current draw when not charging (hopefully less than a few uA's)
 
* minimise current draw when not charging (hopefully less than a few uA's)

Revision as of 13:50, 16 June 2019

For me this charge controller is part of a bigger project, but since it should work fine as a stand-alone solution I thought I'd put it here for the world to see and use.

I will be using the 8-pin 8-bit ATtiny84 for this design.


This charge controller aims to do the following:


  • use battery voltage sensing to detect whether the charging circuit should be activated or not.
  • use a fixed charge current in combination with an LM317 to regulate charge current
  • set final charge voltage using a trimpot
  • enter sleep mode on the microcontroller to save power when the battery is charged.
  • signal charge state with an LED


OPTIONALLY:

  • use a boost converter to allow charging from low input voltages (e.g. 5V from a USB port).


The first version of the charge controller schematic:

0137 schematic v1.0.png




The next step will be to work out the following feature:

  • minimise current draw when not charging (hopefully less than a few uA's)



(to be continued..)