Re: Ping Tester/ Complementary emitter-follower

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

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
 >
 > Original poster: "Jolyon Vater Cox by way of Terry Fritz 
<twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

 > I have posted the schematic of my ping tester at
 > http://hot-streamer-dot-com/temp/PING%20TESTER.jpg.
 >...
 > I am also interested in the possibility of inverting the output on Pin 3 of
 > IC1 with as second 555 (or TLC555) connected as a Schmitt trigger (Pins 2
 > and 6 on the second IC tied together).
 >   the load under test being connected across Pin 3 on IC1 and Pin 3 of IC2.
 > In this configuration the two IC would work together as a full-wave bridge
 > allowing a peak-to-peak voltage of nearly twice that possible with only a
 > single IC.
 > What will be the effect of this on crossover distortion/ step voltage when
 > emitter-followers are added -will it reduce the influence of the voltage
 > step or it worse?

There will be some delay between the switchings of the two output,
distorting the transients. And measurements would be made relative
to ground anyway.

 > With regard to the complementary emitter-follower output stage(s) what
 > transistor type is appropriate given a max frequency of 2.09MHz?

I would have to look in a catalog. A fast switching transistor, or an
RF transistor, would be ok.

 > Finally, if an RC network is used to keep current flowing in the transistors
 > as they change state, what are the appropriate values for C and R again
 > given that the maximum frequency is 2.09MHz?

Maybe better to add a 0.01 uF capacitor in parallel with the 100 uF
capacitor.

Antonio Carlos M. de Queiroz