Hi!
I have a few part selection questions for this project too
R58, R3, R26, and R60 seem to be hard to find in the values stated in MRS25, even if I order them through Farnell. Is there some flex in these values at all, or are the stated values the best choices?
For C6,C7...C18, would 330pF/160V FSC work? I cannot find from Farnell the 390pF parts. They do have 390pF in FSCEX, but I'm not sure they'd fit.
For the "solid electrolytic" I cannot seem to find these at all, despite you giving the BC part number. That includes Farnell, RS Components, and the usual US places (C34, C35, C5, C24, C33). What about tantalum capacitors here?
Thanks!
I have a few part selection questions for this project too
R58, R3, R26, and R60 seem to be hard to find in the values stated in MRS25, even if I order them through Farnell. Is there some flex in these values at all, or are the stated values the best choices?
For C6,C7...C18, would 330pF/160V FSC work? I cannot find from Farnell the 390pF parts. They do have 390pF in FSCEX, but I'm not sure they'd fit.
For the "solid electrolytic" I cannot seem to find these at all, despite you giving the BC part number. That includes Farnell, RS Components, and the usual US places (C34, C35, C5, C24, C33). What about tantalum capacitors here?
Thanks!
Hello,
R3=806 Ohms standard 1% E96
R58=330 Ohms value not critical (power led)
R26=24 kOhms value not critical (23.7 or 24.3k 1% E96 are ok)
R60=64.9 kOhms standard 1% E96
You can use any metal film axial resistor, MRS25 type is what i use but others types are of course perfectly suitable.
For R3 and R60, they value set the oscillating frequency. You can change slightly they values, but the frequency will change too.
For C6,C7, and C18, if you don't find 390pF, you can use 330pF and add 68pF or 47pF in parallel in order to get right value.
With only 330pF, the filtering shape will be different and the oscillator can badly work.
For all solid electrolytic caps, i know that they can be hard to find, you can use standard electrolytic caps without any problem. Costly tantalum can work too, but i don't recommend ti use them...(can explode!).
Regards.
Frex
R3=806 Ohms standard 1% E96
R58=330 Ohms value not critical (power led)
R26=24 kOhms value not critical (23.7 or 24.3k 1% E96 are ok)
R60=64.9 kOhms standard 1% E96
You can use any metal film axial resistor, MRS25 type is what i use but others types are of course perfectly suitable.
For R3 and R60, they value set the oscillating frequency. You can change slightly they values, but the frequency will change too.
For C6,C7, and C18, if you don't find 390pF, you can use 330pF and add 68pF or 47pF in parallel in order to get right value.
With only 330pF, the filtering shape will be different and the oscillator can badly work.
For all solid electrolytic caps, i know that they can be hard to find, you can use standard electrolytic caps without any problem. Costly tantalum can work too, but i don't recommend ti use them...(can explode!).
Regards.
Frex
Frex:
what do you recommend to do with W1 and W2? I assume the idea is a filter, assuming you have enough voltage overhead.. Should I just short them, or populate the 4.7 ohm resistors, or wait until I know what my input voltage is and what it looks like after the regulator? I actually thought they were alternative parts for the 4.7 ohm resistors (to use SMD parts here)... oops, but I see I was wrong. Anyways, just wanted to see what you intended.
what do you recommend to do with W1 and W2? I assume the idea is a filter, assuming you have enough voltage overhead.. Should I just short them, or populate the 4.7 ohm resistors, or wait until I know what my input voltage is and what it looks like after the regulator? I actually thought they were alternative parts for the 4.7 ohm resistors (to use SMD parts here)... oops, but I see I was wrong. Anyways, just wanted to see what you intended.
Hello,
I have sold the last EOSC10kV2 board some weeks ago.
DIYers occasionally ask me circuit board for sale from the previous batch.
So, i have just ordered a new batch of this PCB from the manufacturer, and i will receive them in about 20 days.
I can take your order now and i sending PCB as soon i will receive them.
As my previous PCB sales, i send you a Paypal invoice and you do the payment.
A full design folder including all design files will be send immediatly after payment received (by e-mail).
Price is 30€ for one bare PCB, including worldwide shipping in priority letter (no insurance). It take about 5 days to arrive in EU, 15 days outside EU.
Regards.
Frex
I have sold the last EOSC10kV2 board some weeks ago.
DIYers occasionally ask me circuit board for sale from the previous batch.
So, i have just ordered a new batch of this PCB from the manufacturer, and i will receive them in about 20 days.
I can take your order now and i sending PCB as soon i will receive them.
As my previous PCB sales, i send you a Paypal invoice and you do the payment.
A full design folder including all design files will be send immediatly after payment received (by e-mail).
Price is 30€ for one bare PCB, including worldwide shipping in priority letter (no insurance). It take about 5 days to arrive in EU, 15 days outside EU.
Regards.
Frex
Hi Ken, invoice sent.
Some of bare PCB my others DIY projects are also available for sale :
EOSC10KV2 - 10kHz ultra-low THD super sine oscillator.
AA5381V1 - 24bits/192kHz Measurement High performance Analog to digital Converter.
ERMSDCV2 - DC-1MHz RMS to DC converter & 80dB Ultra Low noise Amplifier.
Frex
Some of bare PCB my others DIY projects are also available for sale :
EOSC10KV2 - 10kHz ultra-low THD super sine oscillator.
AA5381V1 - 24bits/192kHz Measurement High performance Analog to digital Converter.
ERMSDCV2 - DC-1MHz RMS to DC converter & 80dB Ultra Low noise Amplifier.
Frex
I want to tune the Frequency around 3.33khz.
Am i right to multiply the 390pF caps and the 10000pF caps by 3?
The phase shifter circuit (made of 470pf and 2,2n) should be untoched in my opinion.
I made a short simulation with simmetrix, the problem was that i was not able to find the "peak of 5db" at 10khz in the transfair function. So I am not able to check the same thing with 1200pf.
Your documentation is nice! If someone is interested, i can write down my Farnell shopping list (with order Numbers).
What minimum Input Voltage do you suggest with the low noise voltage regulator? Is +-15V enought?
Am i right to multiply the 390pF caps and the 10000pF caps by 3?
The phase shifter circuit (made of 470pf and 2,2n) should be untoched in my opinion.
I made a short simulation with simmetrix, the problem was that i was not able to find the "peak of 5db" at 10khz in the transfair function. So I am not able to check the same thing with 1200pf.
Your documentation is nice! If someone is interested, i can write down my Farnell shopping list (with order Numbers).
What minimum Input Voltage do you suggest with the low noise voltage regulator? Is +-15V enought?
Hello Stephan,
If you want change the oscillator frequency, just modify the Ra/Ca and Rb/Cb network, not others parts.
You can see on the schematic that Fo is 1/(2PIRC) with R=Ra=Rb and C=Ca=Cb.
Don't change the 390pF capacitor.
About my documentation, thank you.
I would be happy to add your Farnell shopping list with order number to my design folder, of course.
About the minimum voltage, you can use two 6F22 battery (9V) if you connect them on the X10/X11/X12 pads.
If you use a main PSU (from 110/220V), you need at least +/-15v for proper operation of the low noise regulator (you must use X5/X6/X7 inputs pads).
Good luck.
Regards.
Frex.
If you want change the oscillator frequency, just modify the Ra/Ca and Rb/Cb network, not others parts.
You can see on the schematic that Fo is 1/(2PIRC) with R=Ra=Rb and C=Ca=Cb.
Don't change the 390pF capacitor.
About my documentation, thank you.
I would be happy to add your Farnell shopping list with order number to my design folder, of course.
About the minimum voltage, you can use two 6F22 battery (9V) if you connect them on the X10/X11/X12 pads.
If you use a main PSU (from 110/220V), you need at least +/-15v for proper operation of the low noise regulator (you must use X5/X6/X7 inputs pads).
Good luck.
Regards.
Frex.
The important thing of the amplifier is, that it does a big phasehift at the resonant frequency.
If i don't change this part of the circuit i will lose performance in gain (but i don't know by what effect the peak is caused) and in phase slope.
I should install LT spice instead of simmetrix.
If i don't change this part of the circuit i will lose performance in gain (but i don't know by what effect the peak is caused) and in phase slope.
I should install LT spice instead of simmetrix.
Last edited:
I installed LTspice. It seems much better than Simetrix.
Here is my first simulation.
The 10khz one is with an 20000p Input cap, the 3khz version is with an 60000p cap.
As i can immagine, the input cap (part of the wien bridge) and the 50pF cap (Part of the LT1007 opamp) forms a capacitive voltage devider So the low freq gain rises!
The gain plot looks more stable, but i must think about the phase reserve....
Here is my first simulation.
The 10khz one is with an 20000p Input cap, the 3khz version is with an 60000p cap.
As i can immagine, the input cap (part of the wien bridge) and the 50pF cap (Part of the LT1007 opamp) forms a capacitive voltage devider So the low freq gain rises!
The gain plot looks more stable, but i must think about the phase reserve....
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