Need a ckt. that will give me 2to5 sec. pulse every 1to2 minutes. Would prefer not to get involved with a microP. Thanks. CP
timer circuit
Apr 14, 2012
6 Replies
If accuracy isn't critical (> 10% variation either way is OK), then a pair of 555 timers (or a 556 dual timer) could provide what you specified.
If timing accuracy is critical, then a simple micro like the PICAXE (under $5, programmed in BASIC) would be a better choice. For even better accuracy, you can add a crystal as the clock source and have one or two seconds per day timekeeping accuracy.
Google "555 timer".
Pilgrim wrote in news:pilgrim-3B1BFC.17302213042012@
70-3-168-216.pools.spcsdns.net:
buy two timing relays.
"Pilgrim"
** Do the above two ranges need to be independently adjustable - or is that the tolerance band ?You need to be FAR more specific.
... Phil
Yes, they should be ind. adj. Accuracy is not important. Thanks CP
snipped-for-privacy@jecarter.us wrote in news: snipped-for-privacy@4ax.com:
for such long timing periods,use a CMOS 7555/7556.
a neat site I found;
formatting link
calculates values for 555 astable timers.
Jim Yanik
jyanik
at
localnet
dot com
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