From: "petrus bitbyter"
Subject: Re: 555 Clock Circuit
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Date: Sun, 15 Sep 2002 23:18:48 GMT
NNTP-Posting-Date: Mon, 16 Sep 2002 01:18:48 MET DST
Organization: chello broadband
If you check out the 555 datasheet you'll find that it is not easily set to
1Hz. Even if you can achieve it, it will be very inaccurate and unstable (as
for the frequency). As others said already for a usefull clock you need a
crystal oscillator. A usefull oscillator can be found in an (old,) battery
powered, "analog" quartz clock. Inside you will find a small pcb wich is
driving a coil, the motor of the clock. Every second the coil gets a pulse.
The pulses come from each side in turn so both sides can be considered a
0.5Hz clockgenerator. As the pcb is originally powered by a 1.5V battery,
you have to make a simple provision to power it from your 5V supply.
Furthermore you have to amplify both pulses and "OR" them to get a 1Hz
"James" schreef in bericht
> Hi all,
> I'm very new to electronics, and just wanted to start with something
> small. I was thinking of constructing a binary clock, and have drawn out
> my design. I was just wondering what to use for the impulse to my 4-bit
> binary counters. I was thinking of using a 555 IC set to 1hz. Is it
> possible to create a clock with the 555 IC, or will it never be accurate
> enough with my cheap materials to produce an Impulse that doesn't lose
> time? Is there any other device that I could use? If it is possible, I
> would like to use the 555, as I already have those on hand and available.
> Thanks for any help in advance,