Beware of the capacitors tolerances (+20/-50%) and there temp.coefficient.
Actually, NE555 is a poor solution if you could have it with a 12C508.
Peter Keller

Caisson schrieb:

> > Van: Lalakis Parafyadas <lalakis_hack@HOTMAIL.COM>
> > Aan: PICLIST@MITVMA.MIT.EDU
> > Onderwerp: [OT]: 1Hz frequency generator with NE555 timer
> > Datum: dinsdag 7 december 1999 15:04
> >
> > Hi there. I'm interested in making a 1Hz frequency generator with a NE555
> > timer. What resistors, capacitors do I need and how should I connect them
> to
> > the chip? Thanks in advance, Argiris
>
> Hello Lalakis,
>
>   From the top of my head:
>
>   Connect Pin 8 & 4 to VCC, Pin 1 to GND.  Connect a resistor from VCC to
> pin 7 (example: 12kOhm).  Connect a somewhat smaller resistor from pin 7 to
> pin 6 (example: 10kOhm).  Connect pin 6 to pin2.  connect a capacitor from
> pin 2 to GND (example: 100uF).  Connect a resistor of 560 Ohm from pin 3 to
> the Annode of a Led. connect the Cathode of the Led to GND.  Pin 5 does not
> have to be connected.
>
> Blinking-speed can be changed by changing any of the resistors and/or
> capacitor.
> For variable speed: place a 10 - 500 kOhm potmeter in series with the
> 12kOhm resistor.
>
> VCC can be anywhere from 3 to 16 Volt.
>
> Regards,
>   Rudy Wieser