propeller dip kit 5V regulator.

PatrickS1981

Hi,

I couldnt find this on the web, but how many amp can I push trough the 5V regulator?

Regards
Patrick

Leon

It depends on the supply voltage.

Toby Seckshund

As Leon says, the max curent that the reg could take is stated on its datasheet. The max voltage that it could withstand will also be stated. Somewhere in between is the reality of its power disipation. Usually the max'es are stated in "a perfect world" ie it has a heatsink with better properties than the iron mass of the Titanic with the iceburg right next to it.

V x I = W, high volts, high amperage equates to hot reg.

What is the reg type (and package) you have ?

http://www.alldatasheet.com/

and

http://www.datasheetarchive.com/

usually can tell you something.

Dr_Acula

Max is 1 amp.

But you might not get to that without it getting hot. Rule of thumb - if it is too hot to touch, add a heatsink.

eg if you run off 8V and using 1 amp then the regulator is dropping 3V at 1A and watts (as above) is 3W. That might need a small heatsink eg a square inch of aluminium. But say you ran it off a 20V supply. Now it is dropping 15V at 1A which is 15 watts.

The better electronics stores will tell you the thermal resistance of their heatsinks. eg a big one might be rated at 0.5C per Watt. So at 15watts it goes up 7.5 degrees C.

In practice, a propeller board might be using 200mA and you might be running from a 9V supply, and so that is 0.2*4 which is 0.8W which would not need a heatsink.

Toby Seckshund

Also the heatsinks are quoted in free air conditions, so it doesn't count if it is jammed into the corner of a small enclosed plastic box, as all things nowerdays seem to be.