Hello AAC, I've been thinking about building a simple system to charge batteries for a while. While looking up DC-to-DC converters I came across this:
http://www.mouser.com/ds/2/405/mc34063a-443483.pdf
By the look of the datasheet, it can take in a good range of input voltages, which is great for me since I'm planning to start by using a repurposed BLDC computer fan and would probably have somewhat inconsistent input, and I can just set it to whatever voltage is appropriate for the battery. As long as I then find a way to monitor the state of charge and stop it when the battery is fully charged, could I use this? It seems so to me, but then I wonder why I haven't heard about anyone using them for small-scale battery charging before. (Also, I would have thought they'd list that as a possible application in the datasheet.)
On a side note, what happens with voltage and current in a typical voltage regulator - say, the LM317? Suppose I put in 10V at 100mA and set it to put out 5V; my intuition is that I would just get 5V at 100mA rather than 5V at 200mA since the latter generally requires more machinery. Is that correct? If so, what happens to the other half a watt? Is it dissipated as heat, or is it in some way "blocked" so that the extra voltage and hence power isn't used in the first place?
Thank you for your help!
http://www.mouser.com/ds/2/405/mc34063a-443483.pdf
By the look of the datasheet, it can take in a good range of input voltages, which is great for me since I'm planning to start by using a repurposed BLDC computer fan and would probably have somewhat inconsistent input, and I can just set it to whatever voltage is appropriate for the battery. As long as I then find a way to monitor the state of charge and stop it when the battery is fully charged, could I use this? It seems so to me, but then I wonder why I haven't heard about anyone using them for small-scale battery charging before. (Also, I would have thought they'd list that as a possible application in the datasheet.)
On a side note, what happens with voltage and current in a typical voltage regulator - say, the LM317? Suppose I put in 10V at 100mA and set it to put out 5V; my intuition is that I would just get 5V at 100mA rather than 5V at 200mA since the latter generally requires more machinery. Is that correct? If so, what happens to the other half a watt? Is it dissipated as heat, or is it in some way "blocked" so that the extra voltage and hence power isn't used in the first place?
Thank you for your help!
