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Topic: The 74HC595 and 0.1uf Capacitor (Read 3953 times) previous topic - next topic

liudr

I have been having good luck without the capacitors, only because my current-limiting resistors are relatively big, like 300ohm. In case you need brighter LEDs with more currents, use a chip that is rated for that kind of work. the 595 is more or less for signals but not for powering high-current loads. I vaguely remember 20mA as maximal per channel. BTW, 0.1uF caps are very cheap. Got a bag of 0.1uF 50V caps from dipmicro.com for around $10. That's what I did with 0.1uF and 22pF caps :)

Also, make sure you have enough delay between shifting data and toggling storage register, according to spec sheet, since you have 9 of them. If you don't consider this aspect, your last few lights will not work regardless what you want them to do, since your toggle arrives before the data.

dannable

Thanks for that last tip liudr. That was something I'd not even thought about!

Beginners guide to using the Seeedstudio SIM900 GPRS/GSM Shield

liudr

#17
Nov 03, 2011, 03:50 am Last Edit: Nov 03, 2011, 06:54 pm by liudr Reason: 1
You are welcome. Somebody else made this mistake (referring to toggling the storage pin too soon after shifting out a long result for like 8 595's in series) a while ago so this is now a part of the forum's accumulated wisdom.

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