# Creating a simple AC transient circuit [Spice]

I’m trying to use the schematic to simulate a very simple circuit with:

1. AC Source 240v Amplitude @ 50Hz.
2. 50 kOhm resister
3. Ground

That’s it! I created the circuit but noted the AC simple has only ONE node you can connect to. I thought it always has + and - (or hot & neutral) sides? At any rate, I connected AC --> Resistor —> GND. Run simulation for transient analysis after some settings and not surprisingly did not get any useful results (all zeros). The spice model for the AC source is: ac 240 sin(0 240 50)

Here is the diagram:

I feel I am missing something obvious and doing something stupid. Any clues appreciated!

Yes I know it’s a two-terminal device, but this one only has ONE terminal.
Where in the library can I find a TWO terminal AC voltage source? I didn’t
find any!

I m new to kicad and I also have similar problem.

``````Circuit: KiCad schematic
Background thread stopped with timeout = 0
Doing analysis at TEMP = 27.000000 and TNOM = 27.000000
Warning: singular matrix:  check nodes vin and vin
Note: Starting dynamic gmin stepping
Trying gmin =   1.0000E-03 Note: One successful gmin step
Trying gmin =   1.0000E-04 Note: One successful gmin step
Trying gmin =   1.0000E-05 Note: One successful gmin step
Trying gmin =   1.0000E-06 Note: One successful gmin step
Trying gmin =   1.0000E-07 Note: One successful gmin step
Trying gmin =   1.0000E-08 Note: One successful gmin step
Trying gmin =   1.0000E-09 Note: One successful gmin step
Trying gmin =   1.0000E-10 Note: One successful gmin step
Trying gmin =   1.0000E-11 Note: One successful gmin step
Trying gmin =   1.0000E-12 Note: One successful gmin step
Trying gmin =   1.0000E-12 Note: One successful gmin step
Warning: singular matrix:  check nodes vin and vin
Warning: Dynamic gmin stepping failed
Note: Starting source stepping
Supplies reduced to   0.0000% Warning: singular matrix:  check nodes vin and vin
Trying gmin =   1.0000E-02 Note: One successful gmin step
Trying gmin =   1.0000E-03 Note: One successful gmin step
Trying gmin =   1.0000E-04 Note: One successful gmin step
Trying gmin =   1.0000E-05 Note: One successful gmin step
Trying gmin =   1.0000E-06 Note: One successful gmin step
Trying gmin =   1.0000E-07 Note: One successful gmin step
Trying gmin =   1.0000E-08 Note: One successful gmin step
Trying gmin =   1.0000E-09 Note: One successful gmin step
Trying gmin =   1.0000E-10 Note: One successful gmin step
Trying gmin =   1.0000E-11 Note: One successful gmin step
Trying gmin =   1.0000E-12 Note: One successful gmin step
Note: One successful source step
Supplies reduced to   0.1000% Warning: singular matrix:  check nodes vin and vin
Supplies reduced to   0.0000% Warning: singular matrix:  check nodes vin and vin
Warning: source stepping failed
Transient solution failed -
Last Node Voltages
------------------
Node                                   Last Voltage        Previous Iter
----                                   ------------        -------------
vout                                              0                    0
vin                                               0                    0
doAnalyses: iteration limit reached
run simulation(s) aborted
``````

Here is my circuit

Any idea where I am wrong ??