MK, field worker and LED strip?

Question

Microcontrollers

hello everyone,
is this trinzyuk enough to power a 12v LED strip of three meters well, 40 watts will come out
www.chipdip.ru/product/irl620 put a relay, but now I think why a relay if you can put field workers + they will not click, advise a field worker for these purposes? Or is it better not to fool around and put a relay? UPD: tape 12v ~ 9.6w / m, i.e. 0.8A per meter of tape? Am I stupid there, will the current increase with each meter or not? I need to feed three meters of tape through a field worker ..... Lena is sequential + I would also like to be able to switch
and what about tip120

Answer 1

Well, let's count.
Current 40 W / 12 V = 3.3333 A.
The field resistance in the on state is 0.8 Ohm, which means that the power dissipation is 0.8 * 3.333 ^ 2 = 8.889 W. on the transistor. That is, out of 40 watts, almost 9 will land on your key. This is not very effective, and it will get very hot. So if you turn it on like this, then only with a radiator, but it’s better to look for a field worker with less resistance when it’s on.

Answer 2

The most common mistake is to power the LEDs with voltage. The characteristics of the LED indicate the operating current, for this current the voltage drop across the LED is indicated. To power the LEDs, current stabilizers are used.
For your case, the calculation is simpler. You need to know the operating current for one LED. If they are connected in series in the tape, then the operating current for the entire tape is equal to the operating current of one LED. The voltage applied to the strip is equal to the sum of the voltage drops across each of the LEDs. It is desirable to include a low-resistance resistor in series in the circuit.