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Topic: The 74HC595 and 0.1uf Capacitor (Read 6154 times) previous topic - next topic

liuzengqiang

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.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

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

liuzengqiang

#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.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

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