Transformer/excitation coil for Armstrong oscillator

Started by Unknown September 24, 2018
On Tuesday, September 25, 2018 at 9:00:34 PM UTC+5:30, Tim Williams wrote:
> <dakupoto@gmail.com> wrote in message > news:7d529c91-326c-4792-b646-98cb0c021df9@googlegroups.com... > > I use Ngspice The netlist is below > > > <snip> > > This is all backwards. It's also not recommended to use SUBCKTs that don't > conserve current (i.e., they are all using the implicit global node 0 for > ground, instead of connecting it through a pin). > > Compare the Armstrong circuit to the netlist, and doublecheck device pin > orders if necessary. > > You also have unused PARAMs, which may be confusing. > > Tim > > -- > Seven Transistor Labs, LLC > Electrical Engineering Consultation and Design > Website: https://www.seventransistorlabs.com/
Well, I am not sure what you mean by "backwards". I have in the past used a dedicated ground pin for SUBCKTs both with HSpice and Ngspice, but I do not think that made any obvious difference in the performance.
On Tuesday, September 25, 2018 at 5:06:41 PM UTC+5:30, Steve Wilson wrote:
> On Tuesday, September 25, 2018 at 5:44:30 AM UTC-4, daku...@gmail.com wrote: > > On Tuesday, September 25, 2018 at 1:11:19 PM UTC+5:30, Steve Wilson wrote: > > > On Monday, September 24, 2018 at 6:29:25 AM UTC-4, daku...@gmail.com wrote: > > > > Could some electronics guru on this group please help ? I am trying to set up a SPICE simulation for an Armstrong oscillator. The problem seems to be with designing the transformer and/or excitation coil. > > > > Are there any good tutorials or related material online. Any hints/ > > > > suggestions would be of immense help. Thanks in advance. > > > > > > Should be easy. Assuming you are using LTspice, post your ASC file. I'll see if I can help. > > > > I use Ngspice The netlist is below > > > > Sorry, I use LTspice. I don't have time to translate your netlist.
That is fine. Both HSpice and Ngspice use text based input netlists, which allows for efficient and intuitive circuit design. For example, a few weeks ago at work I was using Hspice to do some crosstalk simulations with a basic configuration of of 3 microstrip lines, where each microstrip line consists of 1024 unit(series inductor, resistor, shunt capacitor, conductance) cells. Took me about 45 minutes to get the first cut simulation running. I am absolutely sure it would have taken me several hours with a GUI based simulator. I mean just wiring up the whole setup would have been a challenge. .