Battery charger with LM317

[Luis Costa]

Under the schematic supplied by the manufacurer its basically the same as the voltage divider yet with another resistor between the output terminal and R1. Does this much amps damage the battery? its like 0,2 ohms. I've been finding it hard to equate that, Can someone help? Ty

 

[davenn]

Under the schematic supplied by the manufacurer its basically the same as the voltage divider yet with another resistor between the output terminal and R1. Does this much amps damage the battery? its like 0,2 ohms. I've been finding it hard to equate that, Can someone help? Ty

can you please show a circuit so we know what you are referring to


Dave

 

[(*steve*)]

I suspect the resistor in question will be between the 317's output and the voltage divider used to set the output voltage.

If this is the case, then the function of the resistor is to limit the current available at the upper end of the voltage range.

You're almost certainly looking at a charger for a lead acid battery

 

[cjdelphi]

The lm317 can be operated in 2 modes...

Voltage regulation (voltage set from a resistor divider)

Current regulation which limits the output to a set current

 

[Luis Costa]

it has the battery charger mode right? divider with another resistor topping the divider to the output terminal.
https://encrypted-tbn2.gstatic.com/...lgLlKErxbu_4PRNWzNFRVtaTmPAxBGBTu3IenrS-slDQa

yeah i saw Z0=Rs(1+R2/R1)

gets a kinda low impedance but seems enough...
i was thinking 12 at 0.2 ohms giving a straight output current of 60 amps...then some connections got shorted in the pad and it heated intensely, Worked, 0,3/247/442 Ohms for a 3.7 accumulator.