Re: The PING Test

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

At 09:37 PM 9/25/2002 -0300, you wrote:

>> 
>> Antonio -
>> 
>> It may be possible to make a Ping oscillator using a 555 but I have not
>> tried this circuit. It may be necessary to add an operational amplifier to
>> provide a low impedance source.
>
>When the 555 oscillator output goes down, the impedance is low enough
>for
>a "ping" test. When it goes up, it is not. A fast op amp can provide
>lower impedance, but it's a bit more complicated to power and bias
>everything correctly.
> 

Perhaps the CMOS version LMC555 would provide better impedances in both the
high and low cases.

Details of an "real" pinger are at:

http://hot-streamer-dot-com/temp/Paul/4-06/

Far far more than a normal human would want to invest ;-)))  But this is
the machine that did all the Qvar stuff.  2500Volts and a Victoreen spark
gap for that real low Z impedance stuff...

I can't find the on-line schematic right this moment but let me know if
there is interest.  I feed the signal into a TEK TDS3012 scope to a 10,000
point data file were Paul's programs picked that data up and analyzed it.

http://www.abelian.demon.co.uk/tssp/qvar070402/

Cheers,

	Terry