J
jalbers@bsu.edu
Guest
I have been doing some reading on the UJT. Much has been written
about what it takes to turn them on and also about the negative
resistance region but not much discussion on what exactly happens in
the saturation region and aslo what it takes to turn them off. I also
have some other related questions.
Suppose that B2 is connected to a fixed voltage source (10V for
example). Suppose that E is connected to a variable voltage source
(0-10V for example) and B1 is connected to ground. Assume that Etta
is around 0.6 .
Starting out with Ve at zero and raising Ve to just over 6.6V should
cause a small amount of current to flow from E to B1 . I assume that
we are now in the negative resistance region. Beginning to lower Ve
should cause more and more current to flow from E to B1. I assume
that I should be able to stop at any voltage between 6.6 and Vvalley
and have the current hold at some value between Ip and Ivalley. It
appears from the snake shaped graph that after lowering Ve to Vvalley,
raising Ve will even produce more current from E to B1. What would
happen if Ve was brought down below Vvalley? What happens if Ve keeps
increasing after initially being brought down to Vvalley? Also what
has to happen to reset the UJT in other words turn off the current
from E to B1? Also when Ve is between Ve(saturation) and Vvalley, how
does the UJT know which current to use? Acording to the graph the
current could be in the negative resistance region or in the
saturation region?
Suppose that B2 is connected to a fixed voltage source (10V for
example). Suppose that E is connected through a resistor and switch
to the same 10V source. Also B1 is connected to ground. Assume that
Etta is around 0.6 . When the switch is turned on Ve is definitely
above Vp. I assume that in a split second the UJT will travel
completely through the negative resistance region and settle
somewhere? Will Ve settle at Vvalley or Ve(saturation) or somewhere
else? Also what has to happen to reset the UJT in other words turn
off the current from E to B1?
Any help would be greatly appreciated. Thanks
about what it takes to turn them on and also about the negative
resistance region but not much discussion on what exactly happens in
the saturation region and aslo what it takes to turn them off. I also
have some other related questions.
Suppose that B2 is connected to a fixed voltage source (10V for
example). Suppose that E is connected to a variable voltage source
(0-10V for example) and B1 is connected to ground. Assume that Etta
is around 0.6 .
Starting out with Ve at zero and raising Ve to just over 6.6V should
cause a small amount of current to flow from E to B1 . I assume that
we are now in the negative resistance region. Beginning to lower Ve
should cause more and more current to flow from E to B1. I assume
that I should be able to stop at any voltage between 6.6 and Vvalley
and have the current hold at some value between Ip and Ivalley. It
appears from the snake shaped graph that after lowering Ve to Vvalley,
raising Ve will even produce more current from E to B1. What would
happen if Ve was brought down below Vvalley? What happens if Ve keeps
increasing after initially being brought down to Vvalley? Also what
has to happen to reset the UJT in other words turn off the current
from E to B1? Also when Ve is between Ve(saturation) and Vvalley, how
does the UJT know which current to use? Acording to the graph the
current could be in the negative resistance region or in the
saturation region?
Suppose that B2 is connected to a fixed voltage source (10V for
example). Suppose that E is connected through a resistor and switch
to the same 10V source. Also B1 is connected to ground. Assume that
Etta is around 0.6 . When the switch is turned on Ve is definitely
above Vp. I assume that in a split second the UJT will travel
completely through the negative resistance region and settle
somewhere? Will Ve settle at Vvalley or Ve(saturation) or somewhere
else? Also what has to happen to reset the UJT in other words turn
off the current from E to B1?
Any help would be greatly appreciated. Thanks