| Electronics > Projects, Designs, and Technical Stuff |
| Analog circuit analysis discussion – Colpitts oscillator |
| (1/3) > >> |
| AnneRanch:
I am looking to discuss circuit details of Colpitts oscillator. I have found several circuit versions and having a difficult time to model them using Ltspice . My objective is to fully understand individual components functions. I am not looking for troubleshooting , design help , tutorials, u-tube or other references etc. I would like to engage in a meaningful discussion with someone who “been there, done that” on component level. For starters “the circuit configuration should have minimal gain , just to self-start the oscillation” If I select 2N2222 as an active device – how to I make sure it has such “minimal gain “ ? I would appreciate forum members to carefully read my post and reply only when they have a meaningful contribution to post. Cheers |
| ledtester:
Since you mention a specific active device, it would greatly aid the discussion if you posted the particular Colpitts implementaton you are talking about. |
| MagicSmoker:
--- Quote from: AnneRanch on September 17, 2019, 02:48:45 pm ---I am looking to discuss circuit details of Colpitts oscillator. I have found several circuit versions and having a difficult time to model them using Ltspice . --- End quote --- Try setting the minimum maximum time step for the transient analysis in LTSpice to something on par with the period of oscillation if your oscillator isn't oscillating. --- Quote from: AnneRanch on September 17, 2019, 02:48:45 pm ---I would appreciate forum members to carefully read my post and reply only when they have a meaningful contribution to post. Cheers --- End quote --- That's a bit spicy dontchathink? EDIT - oops, mistakenly wrote "minimum time step" instead of maximum. |
| Zero999:
--- Quote from: MagicSmoker on September 17, 2019, 03:09:29 pm --- --- Quote from: AnneRanch on September 17, 2019, 02:48:45 pm ---I am looking to discuss circuit details of Colpitts oscillator. I have found several circuit versions and having a difficult time to model them using Ltspice . --- End quote --- Try setting the minimum time step for the transient analysis in LTSpice to something on par with the period of oscillation if your oscillator isn't oscillating. --- End quote --- Skip initial operating point solution or start DC supply voltages at 0V can also help. --- Quote --- --- Quote from: AnneRanch on September 17, 2019, 02:48:45 pm ---I would appreciate forum members to carefully read my post and reply only when they have a meaningful contribution to post. Cheers --- End quote --- That's a bit spicy dontchathink? --- End quote --- They've probably been trolled in the past. Just ignore posts which don't meaningfully contribute to the discussion or report them to the moderator, if they're that bad. |
| AnneRanch:
Whops I did reply then it asked me to log in AFTERWARS. Not sure why. So hopefully here is the current LTspice file. The model is NOT tuned properly. |
| Navigation |
| Message Index |
| Next page |