Re: 555 timer

On Sat, 25 Mar 2006 01:41:42 GMT, Rich Grise <richgrise@xxxxxxxxxxx>
wrote:

On Fri, 24 Mar 2006 14:53:39 -0600, John Fields wrote:

On 24 Mar 2006 12:49:19 -0800, "minski_wit" <minskii@xxxxxxx> wrote:

hello, this may seem like a dumb question but what do you do to reset a
555 timer on pin 4? 5V, a pulse, etc ?

---
Pull it low.

Is it also not true that it must be pulled high (or allowed to go high) at
the end of the reset interval, before the timing cycle will start?

---
For the device the OP asked about, the 555, releasing the low on the
RESET- input will be sufficient to enable the chip. Whether the
chip will start a timing cycle at that time depends on some other
factors.
---

http://www.national.com/ds/LM/LMC555.pdf - this is the CMOS version;
does anyone use bipolar 555s any more?

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Yes, when the output drive is more than a 7555 can handle and
external components are out of the question, or when a newbie gets
one to start playing with.

--
John Fields
Professional Circuit Designer
.

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