@foogod4237

1 year ago

Sigh.. once again, every single circuit put out by this channel seems to be crap. You cannot just connect up bare LEDs to IC outputs like that. This circuit will fry that counter chip in no time, because you are pulling way too much current through those output pins. According to the datasheet, that chip can handle an absolute max of about 100mW for each output pin. At 9V supply voltage, that means 11mA max. There is no current limiting at all on those LEDs, which means the only reason the LEDs aren't fried instantly is probably because they're being limited by the internal resistance of the IC, which is very very bad and will not last long. If anybody wants to make a version of this circuit that doesn't fry itself after running for a minute or two, make sure to hook up some 330 ohm resistors in series on each of those output lines. That will limit the output current to a level that the chip can actually handle. (if you reduced the supply voltage to 5V (or, say 4.5V (three AA cells)) you could probably get away with 150 ohm resistors instead, which would make the LEDs brighter, while still adequately protecting the chip and the LEDs) (Yes, surprisingly, reducing the battery voltage can actually let you make the LEDs brighter in this case.)

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