[sdiy] inexpensive chips for oscillators (still learning...)

[Tom Wiltshire]

On 26 Sep 2011, at 17:21, Bob K wrote:

> Hi everyone,
> 
> New here.  Hi.  How's everybody?  Fine?  That's good.
> 
> After skimming through the two Forrest Mimms books I have and "Make:
> Electronics", both books are making a point that 555 and 556 chips are
> a good (and cheap) start for breadboarding oscillators.
> 
> I'm planning on a bulk purchase (bulk meaning around 10) of the above
> mentioned chips and was wondering if there are any other cheap chips
> along the lines of the 555 and 556 that can be used for oscillators?
> I'm going to search online for advice as well but thought I'd run this
> question by everybody here.
> 
> Thanks.
> 
> -Bob

Hi Bob,

I used to use the CMOS 4047 chip. For example:

http://uk.farnell.com/texas-instruments/cd4047be/ic-4000-cmos-4047-dip14-18v/dp/1106105

This chip runs the outputs through a flip-flop. This means you get a reliable 50/50 square wave all the time, which you can't say about the 555. Secondly, the oscillator output is also available on pin 13, so you've got another square wave an octave up.

Regards,
Tom