how to choose values for resistors, capacitors, etc. in general circuit design?

[bonbonbaron]

Hi, I'm building a legged robot whose wheels at the base I want to control with an MSP430. I need to build an H-Bridge for each wheel's motor. The motor's stall current is 2A. I can use 4 AA batteries in series, but don't necessarily have to.

I know how most circuit components work and how/when to use them. So my question is, where does one even begin to know what values to use for resistors, capacitors, transistors, and such?

Thanks a bunch in advance!
Michael

 

[KlausST]

Hi,

First you need a schematic.

Then every part in a circuit needs current, voltage ...
In most cases you may use ohm's law to calculate the values.

In many cases the manufacturers of integrated circuits give example circuits with values in their datasheets and application notes.
Also there you may find sections on how to select and calculate the part values of the surrounding devices.

Klaus

 

[jiripolivka]

Hi,

First you need a schematic.

Then every part in a circuit needs current, voltage ...
In most cases you may use ohm's law to calculate the values.

In many cases the manufacturers of integrated circuits give example circuits with values in their datasheets and application notes.
Also there you may find sections on how to select and calculate the part values of the surrounding devices.

Klaus

The process is called circuit design. The designer should have a good knowledge of all circuit details, then he can select optimal values for the components. One can follow manufacturer¨s recommedations, test circuits, etc.