updated 2000.03.30
Author Janez Puhan
Bistable Pushbutton Circuit
The circuit
The circuit shown next has two stable binary states similar to the Schmitt trigger. However, the difference with the Taster circuit is that a pushbutton is needed to activate the state change. The pushbutton is simulated by voltage controlled switch, which is controlled by voltage source v1. When the controlling voltage is zero (v(1) = 0), the pushbutton is opened. When the voltage jumps to 15V, the pushbutton is closed.
The input file
bistable pushbutton circuit
.control
tran 0.02ms 10ms
plot v(1)+20 v(2) v(6)-20 xlabel t[s] ylabel 'v(1) v(2) v(6) [V]'
+ title 'TRAN analysis'
.endc
v1 1 0 dc 0 pulse 0 15V 0.05ms 0 0 0.05ms 2ms
r1 3 6 10k
r2 5 2 100k
c1 2 0 7nF
s1 2 3 1 0 switch
x1 3 5 inverter
x2 5 6 inverter
.subckt inverter 1 2
v1 3 0 dc 15V
d1 1 3 diode
d2 0 1 diode
m1 2 1 3 3 p4007 w=120u l=6u
m2 2 1 0 0 n4007 w=120u l=6u
.model diode d cjo=10pF
.model p4007 pmos
.model n4007 nmos
.ends
.ic v(2)=0 v(3)=15V v(5)=0 v(6)=15V
.model switch sw vt=7.5V
.end
The results
