a tuned (this time) j-Fet amplifier stage
[Eop]
[Eop]
Showing posts with label crystal. Show all posts
Showing posts with label crystal. Show all posts
Wednesday, March 28, 2018
Wednesday, March 21, 2018
yet another 32768Hz Quartz Osc.
Blind tuned to work with some consequences from . . . at 5V v. of it . . .
-- with the single BJT stages and the battery feed and "sensitive"(tuned) oscillators -- it is most unlikely to get anything "properly" to work -- . . . -- moreover with the 1.2 volt battery the grid has to be tuned to work in 3 different areas of operation of the bipolar transistor -- low-voltage (below normal) , normal voltage (for BE CE voltage drops) and hi-voltage (above normal) -- that has to be achieved with fixed biasing elements -- . . . -- in below circuit the critical elements appeared to be C1 , C8 , C4 , C10 -- less C1 more C8 ... also the series connection of C4 and C10 = Cp of the X-tal resonator it first started to "charge" the X-tal with ratio 1.2x : 6x Cp but as i increased C8 the opt. ratio changed to 1.5x : 3x Cp ???
the "above normal" range ↓↓ -- i just fast tuned it just to "charge" the X-tal -- this to see if the current waveform for X-tal goes "trapezoidal" (← failure in a sense of frequency stability -- i assume) or stays Sine . . . . . . . . . well it stayed sine -- but for this one the further frequency tuning and likely some attenuation is a must ↓↓↓↓ (see next) . . .
there is a very simple circuit for 8MHz crystal but (it requires less energy for startup) and it also works only with very narrow range of the supply parameters -- so -- it can't be simply adapted for 32k
. . . ?amazingly i've already proven it otherwise ???
8MHz ::
the C14 caused pulsation is likely causing and the instability in the 5v experiment above ↑↑↑↑
32kHz ::
Low NRG 32k ::
Ultra-tuned UHF ::
nearest match from web
http://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5
The failed but extremely fast starting UHF resonator Osc. experiment
[Eop]
-- with the single BJT stages and the battery feed and "sensitive"(tuned) oscillators -- it is most unlikely to get anything "properly" to work -- . . . -- moreover with the 1.2 volt battery the grid has to be tuned to work in 3 different areas of operation of the bipolar transistor -- low-voltage (below normal) , normal voltage (for BE CE voltage drops) and hi-voltage (above normal) -- that has to be achieved with fixed biasing elements -- . . . -- in below circuit the critical elements appeared to be C1 , C8 , C4 , C10 -- less C1 more C8 ... also the series connection of C4 and C10 = Cp of the X-tal resonator it first started to "charge" the X-tal with ratio 1.2x : 6x Cp but as i increased C8 the opt. ratio changed to 1.5x : 3x Cp ???
the "above normal" range ↓↓ -- i just fast tuned it just to "charge" the X-tal -- this to see if the current waveform for X-tal goes "trapezoidal" (← failure in a sense of frequency stability -- i assume) or stays Sine . . . . . . . . . well it stayed sine -- but for this one the further frequency tuning and likely some attenuation is a must ↓↓↓↓ (see next) . . .
there is a very simple circuit for 8MHz crystal but (it requires less energy for startup) and it also works only with very narrow range of the supply parameters -- so -- it can't be simply adapted for 32k
. . . ?amazingly i've already proven it otherwise ???
8MHz ::
the C14 caused pulsation is likely causing and the instability in the 5v experiment above ↑↑↑↑
32kHz ::
Low NRG 32k ::
Ultra-tuned UHF ::
nearest match from web
http://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5
The failed but extremely fast starting UHF resonator Osc. experiment
[Eop]
Tuesday, August 8, 2017
CMOS osc.-s TEST
! notice the word "test" above !!!
in images
originally with j-FET (← to cancel out BJT feedback to quartz) and BJT (← the low power side) while i realized the j-FET can pretty much do the thing on it's own . . .
the copy paste from NXP-s datasheet (the R3 + diodes added as a speculative 1 startup booster / 2 frequency booster / 3 exponential atenuator)
"alternate compile" of the above prev. (not thoroughly studied !!!)
what the NXP d/s does not tell you . . . about 32kHz quartz (the "C5" is the type of magic wand here)
...
in images
...
Saturday, April 1, 2017
Sine wave crystal oscillator concept
i still poorly understand how to frequency tune this thing . . . but the main concept has been achieved -- a pure undistorted sine wave form for crystal . . .
. . . i find it curious that the appropriate web search can't find any analog circuits for such . . . . . . . . . even more curious is the fact that most micro controllers use digital/discreet stages based quartz drivers that for lower frequency X-tal-s as far as i get attempt to over stress the device and eventually ruin or kill it ???
(8 billion people with no brain on this planet ... statistically impossible but is what the prolonged web search stat.-s retrieves - i roger it but i can't get it - it's insane)
update 2017.04.10 21:41 UTC+3h : revised an old design -- not as good as previous but seemingly near the sine -- also uses a lot of less power -- it likely would work and with even less power but assumingly with longer startup time
[Eop]
. . . i find it curious that the appropriate web search can't find any analog circuits for such . . . . . . . . . even more curious is the fact that most micro controllers use digital/discreet stages based quartz drivers that for lower frequency X-tal-s as far as i get attempt to over stress the device and eventually ruin or kill it ???
(8 billion people with no brain on this planet ... statistically impossible but is what the prolonged web search stat.-s retrieves - i roger it but i can't get it - it's insane)
update 2017.04.10 21:41 UTC+3h : revised an old design -- not as good as previous but seemingly near the sine -- also uses a lot of less power -- it likely would work and with even less power but assumingly with longer startup time
[Eop]