Re: 555 50% duty cycle

["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>

Hi,

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Fucian-at-aol-dot-com>
> 
> Hi, how do i configure the 555 to run in 50% Duty cycle at around 480khtz?Can
> I use the 555 timer calcs?I just need to know the values of the resistors and
> capacitors.

With the standard setup - one cap and two resistors: very small timing
cap <220pF, and discharge resistor >330 Ohm so the 555 doesn't blow
up. Precise 50% isn't possible this way, though.

Alternative - one cap and one resistor: feed the output of the 555
through a timing resistor to the timing cap. Done. Could work with
CMOS no probs, TTL probably needs two transistors as buffers like in
the left part of
http://www.hut.fi/~jwagner/tesla/SSTC/halfbridge-555-drive.gif

cheers,
 - Jan

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