user40860: I am working on a project where I need to use around 50 LED's connected to an Arduino UNO board. To begin with i worked on the tutorial provided by Arduino (https://www.arduino.cc/en/Tutorial/ShiftOut) to connect two shift registers(74HC595). Everything works fine, but the shift registers get very hot in just a few minutes. Is this normal? 

user31105: I can only think about two things:

(least probably): the entrance (VCC) voltage is too high.
(most probably): the resistors to the LEDs are (too) low .. Recalculate the values and check the max amperes which can be handled by the output pins of the shift registers.


40860: <p>I am working on a project where I need to use around 50 LED's connected to an Arduino UNO board. To begin with i worked on the tutorial provided by Arduino (<a href="https://www.arduino.cc/en/Tutorial/ShiftOut" rel="nofollow noreferrer">https://www.arduino.cc/en/Tutorial/ShiftOut</a>) to connect two shift registers(74HC595). Everything works fine, but the shift registers get very hot in just a few minutes. Is this normal? </p>
 31105: <p>I can only think about two things:</p>

<ol>
<li>(least probably): the entrance (VCC) voltage is too high.</li>
<li>(most probably): the resistors to the LEDs are (too) low .. Recalculate the values and check the max amperes which can be handled by the output pins of the shift registers.</li>
</ol>
