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Topic: R/c Transmitter Lipo power. (Read 118 times) previous topic - next topic

ChunksBruv

Hi everyone, I don't post too often but I have a small project to do.
 I have a new r/c transmitter that runs on four AA size battery's.  It runs at 6v, and it seems is not designed to be run at the 4.8v that four AA NiMH batts provide, the battery box is designed that the positive end of the NiMH won't reach the contacts, you know the deal etc. 
I have a spare 11.1v transmitter Lipo that I'm not using so am going to use it for this, I'll use a 7806 and make up a little supply with the capacitors and tiny board.  I have the tiny heat sinks too.  But of coarse the transmitter will show the voltage always at 6v now as its being held there buy the 7806, as long as the lipoly has enough power.  But obviously I need to monitor the lipoly so I don't drop below the lowest cell voltages,  so I know when to charge it. 
I can do this with an Arduino, as I have on my other tank project, but I don't really want to run an Arduino just for that, so I was thinking of doing a two LED indicator thing.  I'm thinking of comparing the voltage from one cell, which is good enough, don't need to check all three, with the six volts from the 7806 and to light either a green or a red LED according to volt level, I want the green to stay on until the cell drops to 3.7v then flick to the red one instead.  Using the simplest amount of components. 
I'm sorta musing on this at the moment and haven't worked out a way of doing it yet!!!,  hahaha.
Maybe two resistors to get the 3.7v split, and then .... Mmmmm.  Any evil geniuses out there!.

ChunksBruv

So a voltage divider with two resistors calculated to get my 3.7v from my regulated 6v,  so I'll have that reference voltage and then the cell voltage.  So have to figure out how to turn the green led on of cell is higher and vice versa when its lower.

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