Does this circuit work only with NONE BUFFERED outputs?. <<<<<<<<<<<<<<<<<<<<Is the question
Does this circuit work only with NONE BUFFERED outputs?.. - the only thing I've not tried yet is trying it on an "odd" value pin rather than an Even pin (mind boggles)
Simple oscillator? That exists?
only when you dont want it to
No, the others are wrong, using a buffered gate has nothing to do with it. A Schmitt trigger oscillator will work equally well whether the gate is buffered or not. Where it does matter whether you use a buffered gate or not is when you use an inverter in linear mode to make an oscillator, such as the usual crystal oscillator circuit (crystal + 2 capacitors + 1 or 2 resistors).
Quote from: Docedison on February 08, 2013, 03:33:48 PM
No just the right chip, your choice of the HC14 was the error, easily fixed, either use 3 gates of a 74HC14 or 1 gate from a CD40106 or a CD4584. You can also use a CD4093 if you tie the inputs together or use one input to gate the oscillator, which is a better option than my suggestion above because there is no startup delay as there is with the diode gate, I've used both many times on many different configurations. Once I set one up driving the gate of a BIG mosfet which switched 12 v to an ignitiion coil and a spark gap that was coupled to a 75 cm ring of 10 Ga copper wire and a 100 PF cap @ 10 KV... Made a great noise source to do a rough noise immunity test. When I initially tested it... It destroyed 3 calculators I had on my bench... About 100 watts of power @ ~ 50 MHz... in 2 hours... From scratch.. @50 MHz. Note: The device was an AM transmitter making power @ 50 MHz modulated by the 2KHz signal from the Cmos gates...
You have to be aware of the difference between buffered and unbuffered CMOS gates (at least in the CD4000 series),
as the buffered versions have extra inverters on inputs and on the outputs - for many of the cunning CMOS analog
circuits you need the UBE versions (unbuffered) IIRC.For a schmitt trigger oscillator though I'm surprised, the hysteresis ought to overcome issues of gain and buffering??
BTW you must properly decouple any CMOS chip used as an oscillator in this way - this could be a source
of misbehaviour.
So who's right here? all i know is my B versions don't oscillate!