Driver Components "Reading" for Newbies...

[kosPap]

Hi all!

while I progress my interests from the general and review discussions to the mod section of the forum I am starting having newbie questions on the driver components...

So my main concern right now is how the magor components define the board characteristics and more specifically how can one understand if the board is:

1. Currnet Regulating
2. Boost AND Buck

For example these boards: (all with an input of 3.0V and boost only)

I can see a capacitor and an inductor on the first. So is this the sytem that controls the constant voltage? In the second board it seems that the mosfet is used instead.

And what about the third?

Also I have a driver with an input range of 3.6-9V, that has 2 capacitors. How advanced (if ) and energy efficient is this application compared to a similar board with mosfet and inductor?

Now you know that I need much tutoring....

Thanks beforehand to those that will take the task of enlightning the uninformed...Kostas

 

[csshih]

I had one of those drivers like the third one.
When I overpowered it, the plastic on the cylindrical thing melted away, showing a coil of wire, any help?

 

[Mr Happy]

It's going to be difficult to tell exactly what a board does just by looking at the components on it.

There are two kinds of regulator:

1. Linear regulators
2. Switching regulators

Linear regulators are "step down" regulators that regulate current by varying the resistance of a transistor in the circuit. These must have a higher input voltage than the required output voltage and will not have any large inductors or capacitors on the board (but may have a large transistor or IC chip requiring heat sinking).

Switching regulators can be buck, boost, or buck-boost. All configurations will have an inductor, a capacitor, and an FET for switching. The difference is in how they are arranged in the circuit. In some cases the FET might be inside an IC and so hidden from view. (There are some voltage boost circuits that use only capacitors, but they are not typically used for driving LEDs.)

The same is true of current regulating and voltage regulating switching circuits. They both have basically the same components of inductor, capacitor and FET, the only difference being how the circuit obtains a feedback signal for regulation. You won't tell this from a cursory glance unless you can recognize a current sense resistor.

Typically your best approach is to identify the specific model or part number of a board and then look up its specifications.

 

[legtu]

I had one of those drivers like the third one.
When I overpowered it, the plastic on the cylindrical thing melted away, showing a coil of wire, any help?

If its still working, then there's no need to worry. What melted is 'just' the inductor's cover/insulator.

As for the dertermining a boards circuit 'type', I'm with Mr Happy. Your best bet is to determine the part number of the 'main' driver/controller and checking its specs.