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Software For Transformer Design Free 16
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Cleopatra Elland
Dec 21, 2023, 7:59:23 PM12/21/23
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I am looking at using a centre tap transformer with a 12mH secondary to drive a 50W 40kHz ultrasonic transducer (4100pF 10-20Ohm resonance impedance) for cleaning applications.The input voltage is 12V at the centre and 0V either side of the primary alternated to switch up the output for 270VAC out of the secondary.
software for transformer design free 16
Download https://t.co/s2vcwWeCZf
My question is what would be the best core/bobbin design for this? To air gap or not to air gap?If using no airgap and using a RC or LC what would be ideal starting values? I am assuming Inductor in series and Capacitor in parallel to the Transducer?
Consider that the piezo transducer is essentially a capacitor at resonance (and near resonance it has an RLC resonant equivalent model); the specs are hopefully declared by the manufacturer or you can measure them yourself. Also many transducer manufacturers also gives specifications for useful drive transformers (some directly sell them!)
40kHz is too much for an iron core (except special laminates, maybe) so you'll probably want to use a ferrite core. Size it for power handling (usually the core datasheets gives a starting idea of the power handling) and then determine the number of spires to avoid saturating the core itself. Usual transformer design really, at least for the first tries. Lots of documentation on the web too (search for 'ferrite transformer design' and similar things).
Ideally you'll want to have the impedance seen from the secondary matching to the transducer one (maximum power transfer law in AC: complex conjugate impedance) but it's almost impossible to compute that before building the transformer.
Normally, a forward (normal, ideal, power supply, impedance matching) transformer would be designed without an airgap to minimise energy storage in the core, and a flyback transformer would use an airgap for maximising the core energy storage.
However, for driving an ultrasonic transducer for cleaning applications, which presumably is single frequency, highest power possible, it may be beneficial to use a non-ideal transformer, to resonate out the transducer capacitance, making the driving amplifier's job somewhat easier.
The first thing to do would be to deliberately introduce some leakage inductance, by separating the primary and secondary windings just the way you wouldn't in a well-coupled transformer. This may only produce a limited amount of leakage, so the next thing is to use an airgap to enhance the effect.
Going from a theoretical leakage inductance to a physical design that will produce that is somewhat tricky, and you might be better off using an ideal (well coupled, no gap) transformer with an external inductance that would be easier to design.
I am looking at using a centre tap transformer with a 12mH secondary to drive a 50W 40kHz ultrasonic transducer (4100pF 10-20Ohm resonance impedance) for cleaning applications. The input voltage is 12V at the centre and 0V either side of the primary alternated to switch up the output for 270VAC out of the secondary.
My question is what would be the best core/bobbin design for this? To air gap or not to air gap? If using no airgap and using a RC or LC what would be ideal starting values? I am assuming Inductor in series and Capacitor in parallel to the Transducer?
If your transformer has a centre tap primary driven in push-pull, that means you have a low impedance drive. You therefore need series resonance in the secondary with an added 4 mH inductor, and a well-coupled gap-less transformer, delivering 28 v RMS. A well-coupled transformer will have negligible leakage inductance, whatever the actual inductance of your secondary is.
You need to determine a few things before you can start to design a transformer, though. At the minimum, these include the input voltage(s) and frequency, and the output voltage(s) and current(s). There may very well be other parameters to consider, both physical and electrical, such as available space for mounting, mounting style, isolation requirements, leakage currents, etc. Environmental conditions may also be a consideration.
The first step is to determine the type of core for the design. You should consult with a core manufacturer to obtain the specific characteristics and power-handling capabilities for each type and size of core. However, a general starting point is:
The primary winding current and wire size needs to be determined. The primary current will be equal to the total output power plus transformer power losses, divided by the primary voltage. For power losses, I start at a 10% increase in the input power, assuming a 90% efficient transformer. For example, a transformer with a 12-V, 2-A output at 120 V input would be:
The next step will be a subject for debate and adjustment depending on the transformer characteristics: I generally start at approximately 500 circular mills (cm) per amp to choose the starting wire gauge. This number may be smaller for small transformers, and larger for large power transformers; that decision is again up to the designer. Using the example above, 0.22 A x 500cm/A = 110cm; I would start with a 29 gauge wire (127.7cm) for the primary.
You now need to determine the number of turns that will be required for each secondary winding. The first step is to use formula 3 (N(s) = V(s) / V(p) x N(p)) to determine the turns for a perfect transformer. This number then needs to be increased to account for the losses in the coils. As a rule of thumb again, I start with a 10% increase in the number of turns, assuming a 90% efficient transformer: N(s) x 1.10 = N Turns. This percentage will vary depending on the characteristics of your design. Use the same method to determine the secondary wire gauge(s) that you used for the primary.
To determine how well the transformer dissipates power losses, we need to calculate the surface area of the completed device. This simply requires looking at all of the surfaces that will be exposed to air and adding them up in inches squared. Now use formula 8 from the design formulas to calculate the estimated temperature rise of the transformer.
Once again, what constitutes an acceptable temperature rise depends on the application and the designer. I always use 50ºC as my maximum rise allowed. Keep in mind that forced air cooling or heat sinks may be used in the end product, which could push that number higher.
The FME Transformer Designer creates .fmxj files, which capture the transformer interface and can be read by FME Workbench. Refer to the Package project structure documentation in the FME Packages SDK for details on where to store the .fmxj within an FME Package.
For my design, I have used Bmax as 35mT, or 3500 gausses. I have calculated primary using this formula.(0.5 * Vin * 10^8)/ 4 * F * Bmax * Cross-section-Area). I have added 0.5 cause my design is Half Bridge. My switching Frequency is 50Khz. And my cross-section area is 2.9cm^2. So the result is 3.69 turn, so have used 4 turns in primary using 6mm square Wire. I need not more than 28mA in Secondary, so I have used 37AWG wire. And the secondary turn I have calculated using *(Vs/Vp)Np= 2666 Turns in secondary. But I have used 3000 turns in secondary.
Why my ferrite transformer drawing 15amp peak at 40-volt RMS at NO loads ?, I mean when the secondary is not generating any ARC or the secondary wires are not even close? I have measured the secondary wire resistance. The resistance is 535 ohms.
If you are trying to get a 100 kV DC output then limit your transformer to producing an RMS output in the mid-kV range i.e. 3 to 5 kV AV and then use a Cockcroft-Walton voltage multiplier on the output that is oil-immersed and I don't mean cooking oil.
The reason I point out about limiting the transformer AC output is that with the number of turns needed, the insulation between secondary layer and the leakage inductance, you'll just about avoid hitting the self-resonant frequency of the transformer. If you hit SRF then you'll get really big problems that you'll never control.
I once designed a 50 kV power supply for an X-ray machine and plenty of days I got cold feet and stress during initial prototype testing. It could produce 4 mA but it was a scary beast. I had my load (and CW multiplier) immersed in a big oil bath and you could see the oil churning with the volts when I was operating at full wack. You should never do this on your own - you need someone in the room with you with a long stick that can press the on-off button on the DC power supply in case you start to fry.
Below is the formula for a solenoid but the same applies for a transformer winding (where \$\mu_0\$ is increased by the relative permeability of the core material and \$\ell\$ is the mean length around the core).
It depends what type of transformer you want. Do you want a normal, forward, power transformer, with output voltage always a turns ratio of the input voltage? Or do you want a flyback transformer, which stores energy, only to release it into the load at a voltage defined by the load and the current?
Sure, this is one good solution to make it just look like a transformer, but any ideas on how to make it real? Also, the spacing between windings is too big or they will start to overlap with each other.
Novel concepts are essential for design innovation and can be generated with the aid of data stimuli and computers. However, current generative design algorithms focus on diagrammatic or spatial concepts that are either too abstract to understand or too detailed for early phase design exploration. This paper explores the uses of generative pre-trained transformers (GPT) for natural language design concept generation. Our experiments involve the use of GPT-2 and GPT-3 for different creative reasonings in design tasks. Both show reasonably good performance for verbal design concept generation.
Of the required transformer design steps for a flyback converter, we begin with the calculation of the numerical values necessary for the design of the transformer, based on power supply specifications. Basically, calculations are made according to the equations provided for each parameter. For your reference, relevant transformer design information is provided in the BM1P061FJ Application Notes and other documents for the IC1 to be used in the design task. In this section, for ease of understanding the parts to be explained are shown in enlarged views. For the structure of the entire circuit, see the section on [Design Example Circuits].
0aad45d008
software for transformer design free 16
Download https://t.co/s2vcwWeCZf
My question is what would be the best core/bobbin design for this? To air gap or not to air gap?If using no airgap and using a RC or LC what would be ideal starting values? I am assuming Inductor in series and Capacitor in parallel to the Transducer?
Consider that the piezo transducer is essentially a capacitor at resonance (and near resonance it has an RLC resonant equivalent model); the specs are hopefully declared by the manufacturer or you can measure them yourself. Also many transducer manufacturers also gives specifications for useful drive transformers (some directly sell them!)
40kHz is too much for an iron core (except special laminates, maybe) so you'll probably want to use a ferrite core. Size it for power handling (usually the core datasheets gives a starting idea of the power handling) and then determine the number of spires to avoid saturating the core itself. Usual transformer design really, at least for the first tries. Lots of documentation on the web too (search for 'ferrite transformer design' and similar things).
Ideally you'll want to have the impedance seen from the secondary matching to the transducer one (maximum power transfer law in AC: complex conjugate impedance) but it's almost impossible to compute that before building the transformer.
Normally, a forward (normal, ideal, power supply, impedance matching) transformer would be designed without an airgap to minimise energy storage in the core, and a flyback transformer would use an airgap for maximising the core energy storage.
However, for driving an ultrasonic transducer for cleaning applications, which presumably is single frequency, highest power possible, it may be beneficial to use a non-ideal transformer, to resonate out the transducer capacitance, making the driving amplifier's job somewhat easier.
The first thing to do would be to deliberately introduce some leakage inductance, by separating the primary and secondary windings just the way you wouldn't in a well-coupled transformer. This may only produce a limited amount of leakage, so the next thing is to use an airgap to enhance the effect.
Going from a theoretical leakage inductance to a physical design that will produce that is somewhat tricky, and you might be better off using an ideal (well coupled, no gap) transformer with an external inductance that would be easier to design.
I am looking at using a centre tap transformer with a 12mH secondary to drive a 50W 40kHz ultrasonic transducer (4100pF 10-20Ohm resonance impedance) for cleaning applications. The input voltage is 12V at the centre and 0V either side of the primary alternated to switch up the output for 270VAC out of the secondary.
My question is what would be the best core/bobbin design for this? To air gap or not to air gap? If using no airgap and using a RC or LC what would be ideal starting values? I am assuming Inductor in series and Capacitor in parallel to the Transducer?
If your transformer has a centre tap primary driven in push-pull, that means you have a low impedance drive. You therefore need series resonance in the secondary with an added 4 mH inductor, and a well-coupled gap-less transformer, delivering 28 v RMS. A well-coupled transformer will have negligible leakage inductance, whatever the actual inductance of your secondary is.
You need to determine a few things before you can start to design a transformer, though. At the minimum, these include the input voltage(s) and frequency, and the output voltage(s) and current(s). There may very well be other parameters to consider, both physical and electrical, such as available space for mounting, mounting style, isolation requirements, leakage currents, etc. Environmental conditions may also be a consideration.
The first step is to determine the type of core for the design. You should consult with a core manufacturer to obtain the specific characteristics and power-handling capabilities for each type and size of core. However, a general starting point is:
The primary winding current and wire size needs to be determined. The primary current will be equal to the total output power plus transformer power losses, divided by the primary voltage. For power losses, I start at a 10% increase in the input power, assuming a 90% efficient transformer. For example, a transformer with a 12-V, 2-A output at 120 V input would be:
The next step will be a subject for debate and adjustment depending on the transformer characteristics: I generally start at approximately 500 circular mills (cm) per amp to choose the starting wire gauge. This number may be smaller for small transformers, and larger for large power transformers; that decision is again up to the designer. Using the example above, 0.22 A x 500cm/A = 110cm; I would start with a 29 gauge wire (127.7cm) for the primary.
You now need to determine the number of turns that will be required for each secondary winding. The first step is to use formula 3 (N(s) = V(s) / V(p) x N(p)) to determine the turns for a perfect transformer. This number then needs to be increased to account for the losses in the coils. As a rule of thumb again, I start with a 10% increase in the number of turns, assuming a 90% efficient transformer: N(s) x 1.10 = N Turns. This percentage will vary depending on the characteristics of your design. Use the same method to determine the secondary wire gauge(s) that you used for the primary.
To determine how well the transformer dissipates power losses, we need to calculate the surface area of the completed device. This simply requires looking at all of the surfaces that will be exposed to air and adding them up in inches squared. Now use formula 8 from the design formulas to calculate the estimated temperature rise of the transformer.
Once again, what constitutes an acceptable temperature rise depends on the application and the designer. I always use 50ºC as my maximum rise allowed. Keep in mind that forced air cooling or heat sinks may be used in the end product, which could push that number higher.
The FME Transformer Designer creates .fmxj files, which capture the transformer interface and can be read by FME Workbench. Refer to the Package project structure documentation in the FME Packages SDK for details on where to store the .fmxj within an FME Package.
For my design, I have used Bmax as 35mT, or 3500 gausses. I have calculated primary using this formula.(0.5 * Vin * 10^8)/ 4 * F * Bmax * Cross-section-Area). I have added 0.5 cause my design is Half Bridge. My switching Frequency is 50Khz. And my cross-section area is 2.9cm^2. So the result is 3.69 turn, so have used 4 turns in primary using 6mm square Wire. I need not more than 28mA in Secondary, so I have used 37AWG wire. And the secondary turn I have calculated using *(Vs/Vp)Np= 2666 Turns in secondary. But I have used 3000 turns in secondary.
Why my ferrite transformer drawing 15amp peak at 40-volt RMS at NO loads ?, I mean when the secondary is not generating any ARC or the secondary wires are not even close? I have measured the secondary wire resistance. The resistance is 535 ohms.
If you are trying to get a 100 kV DC output then limit your transformer to producing an RMS output in the mid-kV range i.e. 3 to 5 kV AV and then use a Cockcroft-Walton voltage multiplier on the output that is oil-immersed and I don't mean cooking oil.
The reason I point out about limiting the transformer AC output is that with the number of turns needed, the insulation between secondary layer and the leakage inductance, you'll just about avoid hitting the self-resonant frequency of the transformer. If you hit SRF then you'll get really big problems that you'll never control.
I once designed a 50 kV power supply for an X-ray machine and plenty of days I got cold feet and stress during initial prototype testing. It could produce 4 mA but it was a scary beast. I had my load (and CW multiplier) immersed in a big oil bath and you could see the oil churning with the volts when I was operating at full wack. You should never do this on your own - you need someone in the room with you with a long stick that can press the on-off button on the DC power supply in case you start to fry.
Below is the formula for a solenoid but the same applies for a transformer winding (where \$\mu_0\$ is increased by the relative permeability of the core material and \$\ell\$ is the mean length around the core).
It depends what type of transformer you want. Do you want a normal, forward, power transformer, with output voltage always a turns ratio of the input voltage? Or do you want a flyback transformer, which stores energy, only to release it into the load at a voltage defined by the load and the current?
Sure, this is one good solution to make it just look like a transformer, but any ideas on how to make it real? Also, the spacing between windings is too big or they will start to overlap with each other.
Novel concepts are essential for design innovation and can be generated with the aid of data stimuli and computers. However, current generative design algorithms focus on diagrammatic or spatial concepts that are either too abstract to understand or too detailed for early phase design exploration. This paper explores the uses of generative pre-trained transformers (GPT) for natural language design concept generation. Our experiments involve the use of GPT-2 and GPT-3 for different creative reasonings in design tasks. Both show reasonably good performance for verbal design concept generation.
Of the required transformer design steps for a flyback converter, we begin with the calculation of the numerical values necessary for the design of the transformer, based on power supply specifications. Basically, calculations are made according to the equations provided for each parameter. For your reference, relevant transformer design information is provided in the BM1P061FJ Application Notes and other documents for the IC1 to be used in the design task. In this section, for ease of understanding the parts to be explained are shown in enlarged views. For the structure of the entire circuit, see the section on [Design Example Circuits].
0aad45d008
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