v 20130925 2
C 40000 40000 0 0 0 title-A4.sym
C 49200 44600 1 90 1 capacitor-1.sym
{
T 48500 44400 5 10 0 0 270 2 1
device=CAPACITOR
T 49500 44100 5 10 1 1 0 6 1
refdes=C2
T 48300 44400 5 10 0 0 270 2 1
symversion=0.1
T 49100 44000 5 10 1 1 180 6 1
value=10nF
}
C 49900 45000 1 90 1 capacitor-1.sym
{
T 49200 44800 5 10 0 0 270 2 1
device=CAPACITOR
T 50200 44500 5 10 1 1 0 6 1
refdes=C3
T 49000 44800 5 10 0 0 270 2 1
symversion=0.1
T 49800 44400 5 10 1 1 180 6 1
value=10nF
}
C 43100 46500 1 270 0 capacitor-2.sym
{
T 43800 46300 5 10 0 0 270 0 1
device=POLARIZED_CAPACITOR
T 43700 46100 5 10 1 1 0 0 1
refdes=C1
T 44000 46300 5 10 0 0 270 0 1
symversion=0.1
T 43600 45800 5 10 1 1 0 0 1
value=10uF
}
C 49800 45900 1 90 1 resistor-1.sym
{
T 49400 45600 5 10 0 0 270 2 1
device=RESISTOR
T 49500 45500 5 10 1 1 0 6 1
refdes=RB
T 49100 45400 5 10 1 1 180 6 1
value=4.7K
}
C 49800 46800 1 90 1 resistor-1.sym
{
T 49400 46500 5 10 0 0 270 2 1
device=RESISTOR
T 49500 46400 5 10 1 1 0 6 1
refdes=RA
T 49100 46300 5 10 1 1 180 6 1
value=4.7K
}
C 42700 44800 1 0 0 gnd-1.sym
N 42300 47100 43300 47100 4
N 42300 47100 42300 46600 4
N 43300 46500 43300 47100 4
N 42300 45400 42300 45100 4
N 42300 45100 43300 45100 4
N 43300 45100 43300 45600 4
N 48900 45900 49700 45900 4
N 47900 46300 47900 46800 4
N 47100 46300 47100 46800 4
N 47100 46800 49700 46800 4
N 46300 45000 46100 45000 4
N 46100 47500 46100 45000 4
N 48600 45000 50200 45000 4
N 50200 47500 46100 47500 4
{
T 47900 47600 5 10 1 1 0 0 1
netname=Trigger
}
N 49000 44600 48600 44600 4
N 46300 43200 46300 43900 4
C 48500 43500 1 270 0 resistor-1.sym
{
T 48900 43200 5 10 0 0 270 0 1
device=RESISTOR
T 49200 43300 5 10 1 1 180 0 1
refdes=Rout
T 49100 43000 5 10 1 1 180 0 1
value=10k
}
C 49600 43400 1 0 0 gnd-1.sym
C 48500 42300 1 0 0 gnd-1.sym
T 45900 40900 9 10 1 0 0 0 1
LM555 Astable Square Waveform Generator
T 44700 40400 9 10 1 0 0 0 1
timer-lm555.sch
T 45300 40100 9 10 1 0 0 0 1
1
T 46300 40100 9 10 1 0 0 0 1
1
T 48600 40400 9 10 1 0 0 0 1
2015 - 04 - 14
T 48600 40100 9 10 1 0 0 0 1
Jason Uher & Mike Waters
C 42600 45400 1 0 1 vdc-1.sym
{
T 41800 46050 5 10 1 1 0 6 1
refdes=V1
T 41900 46250 5 10 0 0 0 6 1
device=VOLTAGE_SOURCE
T 41900 46450 5 10 0 0 0 6 1
footprint=none
T 41900 45750 5 10 1 1 0 6 1
value=DC 5V
}
C 42600 47100 1 0 0 vcc-1.sym
C 48300 46800 1 0 0 vcc-1.sym
N 50200 47500 50200 45000 4
N 48900 45900 48900 45400 4
N 48900 45400 48600 45400 4
C 46200 42900 1 0 0 gnd-1.sym
C 46300 43500 1 0 0 lm555-1.sym
{
T 48100 43500 5 10 1 1 0 0 1
refdes=X1
T 46300 43500 5 10 0 0 0 0 1
value=LM555
}
N 48600 43900 48600 43500 4
N 49000 43700 49700 43700 4
N 49700 44100 49700 43700 4
T 40300 42900 9 10 1 0 0 0 6
This example can be a bit tricky to simulate.
The following combination has worked :

  GNU-Cap, Transient analysis. Start Time = 0,
  End Time = 300usec, Step Inc. = 1 usec.
  No Signal Source. Cold or Warm IC's.
T 40300 41900 9 10 1 0 0 0 1
GNU-Cap Osc. Freq. = 9.9 KHz KHz
T 40300 42100 9 10 1 0 0 0 2
Calculated Osc. Freq. = 1.44 / ((RA + 2 * RB) * C3)
                                    = 10.2 KHz
T 40300 42500 9 10 1 0 0 0 1
Data sheet Osc. Freq. = 11 KHz
T 40300 40400 9 10 1 0 0 0 6
Note : This SPICE model of the LM555
           seems to work better at lower
           frequencies. As the frequency
           increases >50KHz oscillator
           frequencies are significantly
           under estimated.
C 45500 41600 1 0 0 spice-model-1.sym
{
T 45600 42300 5 10 0 1 0 0 1
device=model
T 45600 42200 5 10 1 1 0 0 1
refdes=A1
T 46800 41900 5 10 1 1 0 0 1
model-name=LM555
T 46000 41700 5 10 1 1 0 0 1
file=../../lib/models/lm555.mod
}