You have no Simulation GND in the 8.x version. Look under the Spice schematic parts and read the KiCad docs on simulation online.
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On 11/01/2025 20:28, Bob Kuczewski via groups.io wrote:
I've been trying to simulate a simple oscillator using 2 BJT transistors in KiCad, and I'm having some trouble. I've tried it in both KiCad 5.0.2 and 8.0.7. I'm not sure what information to provide for help (netlist, schematic, something else?), so I'll start with two pictures and some NGSPICE code. Here's the one from KiCad 5.0.2:
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And here's the one from 8.0.7:
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I've gotten it to work directly in NGSPICE as shown in this plot:
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Here's the working NGSPICE code if it helps:
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* Vname PosNode NegNode ...
VCC 6 0 DC 5V
* Rname PosNode NegNode Value
RC1 6 1 1K
RC2 6 2 1K
R1 ?6 3 30K
R2 ?6 4 30K
* Cname PosNode NegNode Value
C1 ?1 4 150PF
C2 ?2 3 150PF
* Q1 and Q2 with model QM and substrate connected to ground by default
* ?C B E
Q1 1 3 0 QM
Q2 2 4 0 QM
* Model statement defining QM as an NPN transistor
.MODEL QM NPN (IS=2E-16 BF=50 BR=1 RB=5 RC=1 RE=0 TF=0.2NS TR=5NS)
.NODESET V(1)=0 V(3)=0
.TRAN 0.1US 20US
.OP
* Generate the plots (running twice for some reason)
.control
reload
run
reset
run
plot V(1) V(2) V(3) V(4)
.endc
.END
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It also works in real life on a bread board.? :)
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Any suggestions would be helpful. Thanks.
