I made the circuit as above. When I checked the voltage at the collector, I got the following signal.



The frequency is too high. I want to lower frequency. Targets range from about 100 kHz to 200 kHz. Please teach me the way.

 

I'm not sure you have an oscillator with a frequency you can predict or control. How were you planning on controlling it?
I kind of remember things like that from 60 years ago, but I never had occasion to use one because many better alternatives were available.

 

I'm not sure you have an oscillator with a frequency you can predict or control. How were you planning on controlling it?

I thought the frequency would change if I changed the resistance and cap values. Am I wrong?

 

Changing the resistors will change the DC bias on the transistor. Usually, an oscillator wants a stable bias so I'm not sure that is a useful way to go. What are you trying to accomplish with this monstrosity?

 

Changing the resistors will change the DC bias on the transistor. Usually, an oscillator wants a stable bias so I'm not sure that is a useful way to go. What are you trying to accomplish with this monstrosity?

I would like to output a voltage of 1kV to 2kV. A multiplier is connected to the secondary side of the transformer.
I made the transformer myself. The transformer worked well at 100 kHz. The 23 MHz frequency did not transform well.

 

The phasing of the base and collector windings looks wrong. Try reversing the connections to one of the windings if they are actually wired that way.

 

It is a Hartley Oscillator made a little confusing.


The frequency can be varied by changing the Tank capacitor, C1

 

A Square-Wave-Oscillator would be more efficient when driving a Voltage-Multiplier,
and eliminating the Voltage-Multiplier,
and increasing the Transformer-Secondary-Turns,
would be even more efficient.

How much Current do You need at ~2K-Volts ?
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A Square-Wave-Oscillator would be more efficient when driving a Voltage-Multiplier,
and eliminating the Voltage-Multiplier,
and increasing the Transformer-Secondary-Turns,
would be even more efficient.

How much Current do You need at ~2K-Volts ?
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I need about 250uA, that is, 500mW.

 

The phasing of the base and collector windings looks wrong. Try reversing the connections to one of the windings if they are actually wired that way.

Yes, thank you. I'll give it a try.

 

I am not an expert at all, but after actively learning the basics of the most common topologies, for 1,2 MHz, found the Clapp oscillator not difficult to deal with.

 

Use an SG2524 IC Regulator/Controller ( DIP-16 ),
DigiKey p/n 296-9685-5-ND,
<~$2.oo, >~800 in stock,
easy to work with,
Fully-Symmetrical-Push-Pull-Output,
Adjustable-Frequency,
Current-Limited,
Voltage-Regulated-Output,
very stable with varying Loads,
electrically very quiet for an SMPS Power-Supply ---> easier to filter Output.
( may require one very small additional Transformer-Winding for monitoring Output-Voltage,
this is easier than trying to "pad-down" the extremely high Output-Voltage for Regulation-Feedback ).

https://www.digikey.com/en/products/detail/microchip-technology/SG2524N/13472606?s=N4IgjCBcpgbFoDGUBmBDANgZwKYBoQB7KAbXAAYB2ADkoE4QBdAgBwBcoQBlNgJwEsAdgHMQAXwJg61BtBDJI6bPiKkQ5Jqw6RufIaIkgAtPDkK+AVxXFIZAMxNDRgEwJ5US9bUNGYw69tuAHFnAFZnABZHIA
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for voltage "stabilizers" they use a resonant LC tank (as for resonant boost converters) ← while trying to spot one of the joule thief type i stumbled upon https://www.homemade-circuits.com/8x-overunity-circuit-using-joule-thief/ (← usually those things are impossible to get up to high efficiency at low voltage input ????)

 

for voltage "stabilizers" they use a resonant LC tank (as for resonant boost converters) ← while trying to spot one of the joule thief type i stumbled upon https://www.homemade-circuits.com/8x-overunity-circuit-using-joule-thief/ (← usually those things are impossible to get up to high efficiency at low voltage input ????)

This link claims 'overunity' so it is dodgy before we even start.

 

The phasing of the base and collector windings looks wrong. Try reversing the connections to one of the windings if they are actually wired that way.

Thank you. you were right. When I changed the direction of the feedback winding, the frequency dropped. I succeeded in making 1kV output. Thank you.

 

Use an SG2524 IC Regulator/Controller ( DIP-16 ),
DigiKey p/n 296-9685-5-ND,
<~$2.oo, >~800 in stock,
easy to work with,
Fully-Symmetrical-Push-Pull-Output,
Adjustable-Frequency,
Current-Limited,
Voltage-Regulated-Output,
very stable with varying Loads,
electrically very quiet for an SMPS Power-Supply ---> easier to filter Output.
( may require one very small additional Transformer-Winding for monitoring Output-Voltage,
this is easier than trying to "pad-down" the extremely high Output-Voltage for Regulation-Feedback ).

https://www.digikey.com/en/products/detail/microchip-technology/SG2524N/13472606?s=N4IgjCBcpgbFoDGUBmBDANgZwKYBoQB7KAbXAAYB2ADkoE4QBdAgBwBcoQBlNgJwEsAdgHMQAXwJg61BtBDJI6bPiKkQ5Jqw6RufIaIkgAtPDkK+AVxXFIZAMxNDRgEwJ5US9bUNGYw69tuAHFnAFZnABZHIA
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First of all, I purchased the parts you recommended. It looks like I can make high voltage more stable. However, it will take time for me to receive the parts and understand the datasheet. Anyway, thank you for the advice.

 

is dodgy

. . . what you miss here is that the article claims the oscillator being a resonant type . . . however i tend to believe - it has little effect (a narrow outp regulation range/capability) at this particular osc. . . . however - if the cause for such effect is being studied and anderstood - one can design a better variant with a wider reg.-n range
note. : it's easy to label people idiots - not seeing what they actually have said of value

 

note. : it's easy to label people idiots - not seeing what they actually have said of value

When a person or situation is called dodgy, it's a clue that they should be dodged if at all possible. Over unity is a no no to discuss.
I believe it was only an abundance of caution.

 

Use an SG2524 IC Regulator/Controller ( DIP-16 ),
DigiKey p/n 296-9685-5-ND,
<~$2.oo, >~800 in stock,
easy to work with,
Fully-Symmetrical-Push-Pull-Output,
Adjustable-Frequency,
Current-Limited,
Voltage-Regulated-Output,
very stable with varying Loads,
electrically very quiet for an SMPS Power-Supply ---> easier to filter Output.
( may require one very small additional Transformer-Winding for monitoring Output-Voltage,
this is easier than trying to "pad-down" the extremely high Output-Voltage for Regulation-Feedback ).

https://www.digikey.com/en/products/detail/microchip-technology/SG2524N/13472606?s=N4IgjCBcpgbFoDGUBmBDANgZwKYBoQB7KAbXAAYB2ADkoE4QBdAgBwBcoQBlNgJwEsAdgHMQAXwJg61BtBDJI6bPiKkQ5Jqw6RufIaIkgAtPDkK+AVxXFIZAMxNDRgEwJ5US9bUNGYw69tuAHFnAFZnABZHIA
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I'm not used to looking at the datasheet, so I just don't understand. Can you tell me how to drive this chip? Or just 'Refer to a few pages of the datasheet'.

 

Reading a Data-Sheet is just like learning any other subject,
You have to start by getting simple definitions of every single word that You don't completely understand,
after a few years of doing this, You will start to see that newer types, or more complex types,
of Circuits and Circuit-working-principles start to make much more sense.
Just keep on pushing and asking questions and you'll start becoming more competent.
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This Schematic has errors on the Output Filter, (missing Resistor), and on the attachment point of
the Output-Voltage-Feedback-Wire, which should be attached after the first stage of the Filter, not the second stage.
Also, the values of the Oscillator-components have not been added to the Schematic.
Otherwise it works well as shown.