Help finding literature?

[Devlan]

Hey, sorry if this went into the wrong forum, but I am in school so I kinda figured it fitted.

I've already had a fair bit of basic electric circuit theory, but haven't done much practical work yet. Thing is, all the books and sources I have are utterly theoretical and doesn't really offer much in the way of assistance for taking the first tottering steps in actually applying the knowledge. So, in looking around for material I found this forum and thought maybe someone here could throw out a few tips?
I've been looking ahead a bit in our curriculum and saw that we're going to get an exercise in designing a circuit with a battery and battery charger and dimension loads and heat sinks after our own head and a small list of requirements. So if you have any tips on learning how to do that sort of work I'd be glad to have them! Ah, I might mention that there isn't much help in the mandatory course literature for that one; I think part of the idea is that we should use whatever we have at our disposal and find the necessary knowledge without teacher assistance.

Anyway, thanks in advance for any books or material you have to recommend!

 

[alec_t]

There are many examples of battery-charger schematics on the web. Googling for those might be a good starting point. There are also several circuits on this site (click on the circuits tab) which are suitable for beginners.
If heat sinks are involved then an understanding of 'thermal resistance' will be needed.

 

[simonbramble]

A battery charger is essentially just a current source. The size of the current is normally rated in units of 'C'. If you have a 1 amperehour battery and charge at C, you will be charging at 1 Amp. If you charge at C/2, you will be charging at 500mA. Likewise for a battery with a 3Ahr capacity and you charge at C, you will be charging at 3A. So C is the current it takes to charge the battery to full capacity in the space of 1 hour. Normally battery chargers charge with a current of approximately C or C/2.

The important thing is charge termination. I suggest you read up on charge termination for NiCad, Nickel Metal Hydrides, lead acid and Lithium batteries. Each is different.

As alex says, the main problem with battery chargers is heat disspation in the charger, so this needs thinking about too