Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Users Search
Help Dashboard Sign In Sign Up
Q&A Papers Meta
Q&A
Posts Tags Edits
Ask Question

Post History

50%
+0 −0
Q&A Results of analysis of Hartley oscillator dont make sense

This LC circuit depends on several criteria for stable linear oscillation; 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or ...

posted 2y ago by TonyStewart‭  ·  edited 2y ago by TonyStewart‭

Answer
#9: Post edited by user avatar TonyStewart‭ · 2022-08-13T15:44:26Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • This design is not intended to be ideal, and there are better designs that have much higher Q for square wave clocks or nonlinear feedback for sine amplitude unity-gain AGC-like control.
  • https://tinyurl.com/2nu4eyrb
  • ![bode](https://electrical.codidact.com/uploads/9X8nW1A1XKoLBFFSGZRAKUjA)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • This design is not intended to be ideal, and there are better designs that have much higher Q for square wave clocks or nonlinear feedback for sine amplitude unity-gain AGC-like control.
  • https://tinyurl.com/2nu4eyrb
  • ![bode](https://electrical.codidact.com/uploads/hnbeCU1otSXh4fvV83q93KwK)
#8: Post edited by user avatar TonyStewart‭ · 2022-08-13T15:42:16Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • This design is not intended to be ideal, and there are better designs that have much higher Q for square wave clocks or nonlinear feedback for sine amplitude unity-gain AGC-like control.
  • https://tinyurl.com/2nu4eyrb
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • This design is not intended to be ideal, and there are better designs that have much higher Q for square wave clocks or nonlinear feedback for sine amplitude unity-gain AGC-like control.
  • https://tinyurl.com/2nu4eyrb
  • ![bode](https://electrical.codidact.com/uploads/9X8nW1A1XKoLBFFSGZRAKUjA)
#7: Post edited by user avatar TonyStewart‭ · 2022-08-13T15:40:10Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • This design is not intended to be ideal, and there are better designs.
  • https://tinyurl.com/2nu4eyrb
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • This design is not intended to be ideal, and there are better designs that have much higher Q for square wave clocks or nonlinear feedback for sine amplitude unity-gain AGC-like control.
  • https://tinyurl.com/2nu4eyrb
#6: Post edited by user avatar TonyStewart‭ · 2022-08-13T15:38:30Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • This design is not intended to be ideal, and there are better designs.
  • https://tinyurl.com/2nu4eyrb
#5: Post edited by user avatar TonyStewart‭ · 2022-08-13T15:21:00Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift plus 180 degree inversion
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift ( with 3rd order LC network) plus 180 degree inversion to achieve the oscillation criteria of 0 or 360 deg at gain >=1 Thus each reactance affects fo.
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
#4: Post edited by user avatar TonyStewart‭ · 2022-08-13T07:38:56Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift plus 180 degree inversion
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • An improvement was made adding the L1,L2 ground resistance for a deeper notch effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift plus 180 degree inversion
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • A variation was made by adding the L1,L2 ground resistance for a notch filter effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • The highlight of this answer is to show the results of resistance ratios and hFE can be significant.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
#3: Post edited by user avatar TonyStewart‭ · 2022-08-13T07:24:03Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift plus 180 degree inversion
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • An improvement was made adding the L1,L2 ground resistance for a deeper notch effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift plus 180 degree inversion
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • An improvement was made adding the L1,L2 ground resistance for a deeper notch effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE = 10 to 50.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
#2: Post edited by user avatar TonyStewart‭ · 2022-08-13T07:23:25Z (over 2 years ago)
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift plus 180 degree inversion
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • An improvement was made adding the L1,L2 ground resistance for a deeper notch effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE.
  • ![sim](https://electrical.codidact.com/uploads/QKdrsPRNqGW8D7hRPaE6MJ8e)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
  • This LC circuit depends on several criteria for stable linear oscillation;
  • - 180 deg phase shift plus 180 degree inversion
  • - adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
  • - Only 1 capacitor is necessary
  • An improvement was made adding the L1,L2 ground resistance for a deeper notch effect.
  • - keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements.
  • - The feedback cap. and H bias were also replaced with one feedback resistor, R2
  • - By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave.
  • - Excess gain will clip the sine wave.
  • The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE.
  • ![sim](https://electrical.codidact.com/uploads/V2v4Y2nCdGzEXEvjjB1tHaR3)
  • [Falstad Simulation]
  • https://tinyurl.com/2nu4eyrb
#1: Initial revision by user avatar TonyStewart‭ · 2022-08-13T07:22:38Z (over 2 years ago) 
This LC circuit depends on several criteria for stable linear oscillation;

- 180 deg phase shift plus 180 degree inversion
- adequate bias current and impedance ratios with negative feedback ratios at DC and at fo.
- Only 1 capacitor is necessary

An improvement was made adding the L1,L2 ground resistance for a deeper notch effect.
- keeping the resistance ratios of R2/R3=1.5 to 3 range that affects feedback attenuation and impedance range used to satisfy requirements. 
- The feedback cap. and H bias were also replaced with one feedback resistor, R2
- By tuning hFE to lower values, one can improve R ratios for sufficient gain to oscillate with pull up/down for a symmetrical sine wave. 
- Excess gain will clip the sine wave.

The sensitivity to each resistance part value in the simulation gives more insight than the math and leads to a stable result. In reality, hFE is nonlinear with current, but I did add a slider for constant hFE.





![sim](https://electrical.codidact.com/uploads/QKdrsPRNqGW8D7hRPaE6MJ8e)

[Falstad Simulation]

https://tinyurl.com/2nu4eyrb