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Singular Matrix error node on LTSpice

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Stephane38

New Member
Hi,

I have designed some piezo harvested circuits designed in LTspice as attached.
The first one is a simple case, the piezo is modelised by the current source I1 and the C1 capacitor. Then there is an diode bridge and finally a storage capacitor C2.

In the second design, I added a sw which has to closed when the I1 current reach 0A (SSDC).
When i want to run my design with an 0.025A, it poped up with "Singular Matrix: check node entre- Iteration no4"
BUT when I change to a 0.024A, there is no pb and I have the results I want.

Then the last circuit arrives, it's the same with an inductor (SSDCI).
It poped up with "Singular Matrix: check node n001 Iteration no4"
So there is a pb with C1 node. When I add a node to n001, the problem is solved but that isn't the results I want to use the diode bridge rectifier (like the first circuit but with an switch).

If someone can help me please ?:(
 

Attachments

  • pizo_harverster_impedance_adaptation.asc
    1.3 KB · Views: 236
  • pizo_harverster_SSDC_ideal_switch.asc
    1.7 KB · Views: 197
  • piezo_harvester_SSDCI_ideal switch.asc
    2.2 KB · Views: 209
Use 'real' diodes instead of the default generic ones and the sims should run ok.
Welcome to ETO!
 
Hi,

I have designed some piezo harvested circuits designed in LTspice as attached.
The first one is a simple case, the piezo is modelised by the current source I1 and the C1 capacitor. Then there is an diode bridge and finally a storage capacitor C2.

In the second design, I added a sw which has to closed when the I1 current reach 0A (SSDC).
When i want to run my design with an 0.025A, it poped up with "Singular Matrix: check node entre- Iteration no4"
BUT when I change to a 0.024A, there is no pb and I have the results I want.

Then the last circuit arrives, it's the same with an inductor (SSDCI).
It poped up with "Singular Matrix: check node n001 Iteration no4"
So there is a pb with C1 node. When I add a node to n001, the problem is solved but that isn't the results I want to use the diode bridge rectifier (like the first circuit but with an switch).

If someone can help me please ?:(

Hi

Use the "startup" option with the tran statement, like this:

tran 2 startup

or check the checkbox "Start external DC supply voltages at 0v:".

If you don't do this then the simulator expects the user to set all initial operating conditions.

After I checked this box all ran with no issues.

eT
 
Use 'real' diodes instead of the default generic ones and the sims should run ok.
Welcome to ETO!
Thanks a lot it is working now!

Hi

Use the "startup" option with the tran statement, like this:

tran 2 startup

or check the checkbox "Start external DC supply voltages at 0v:".

If you don't do this then the simulator expects the user to set all initial operating conditions.

After I checked this box all ran with no issues.

eT
Hey, it didn't fixed my pb but it is good to know!

Thanks guys
 
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