Re: Interference-SSTC

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jan Florian Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>


> Im getting TV and radio interference.I have put my 555 timer into a metal 
> enclosure including a regulated PSU.Do i conncet this to house ground?

Yup, house ground.

> Also, I am having timer chip probs.They refuse to work with 50% duty cycle 
> config.They work fine with the 2 pot version.Why?

If it is the TTL version of the 555 - in my experience, these don't work
so awfully well in the 50% configuration (1 resistor 1 capacitor) beyond
350kHz or so. The CMOS ones work definitely better.

You can also use the very cheap CD4046. It has some "unnecessary" stuff on
board, as you need only the VCO. It gives out 50% always, up to 4 MHz I
think, and is as simple to use as the 555. But, it has even less output
current so you need a complementary emitter follower on the output to
boost the current.

There are probably many other clock chips that could be used, too. But
right now I can't think of any... 

cheers,
 - Jan

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