the circuit is just like Stans patentyou posted,the square wave is on pin 8 of the 7408,without pin 8 of 74122 conected,the ripples is with the pin 8 of 74122 con to pin 5 of 7408Quote from Faisca on June 14th, 2012, 04:23 PM what is going on "74122"?Quote from adys15 on June 14th, 2012, 02:18 PM hey guys today i bouth another 74ls08 and test the gate circuit again,but no results,the square wave is without the pin 8 of 74122 conected to pin5 of 7408,and the messy wave is with the two conected...can anyone give a clue,i checed 1000 time ,same result,,,anyone has a working gate circuit???stans does not seems to work or the 74122 is broken!!
Pin "8" is high or low?
You have not sent the schematic.
Again, this part of the gate is not important, not now.
I'm sending the original of Meyer. Now identify your circuit in the figure. and show me where this square wave and seeing the other comments it deems relevant.
the gating is important because I finished the vic and canot test it,what do i conect to scanner?? if i dont have all the circuits
You're heating up your head with anything. (Missing school).
Consider:
This part of the circuit, if not enter anything, nothing happens (as you say, as you saw).
At the entrance (M1 or B) if there are pulses, they are attuned / different (by two "nor-gate") feeding pin "3" and "4" "74122", this will be set the pulse width (the "P5 ").
In the [K] if so, disable pin "4" 7408 ("and gate") the same thing with the pin "9" ("cell off"), disabling the output [A] in "Q11".
In other words, insert pulses [M] or and observe them in [A], if you turn the key "cell off" or get in [K], no longer will have output [A]
I recommend: Do not disconnect pin "5" and "8". (to do this?) doing this will get noise and this is what you are seeing.
This is not the most productive way to learn electronics, not this forum, here we are learning the technology of Meyer.