Design and fabrication of a custom capacitor with better spec.s than my design.
- Status: Closed
- Hadiah: $1500
- Penyertaan diterima: 7
- Pemenang: jobeps
Help needed with electrical engineering, mechanical engineering, materials engineering. I am an engineer working for the Vasant Corporation. I designed a custom capacitive/inductive resonator but the present design has too low of energy density.
This resonator design is to be used in the base of a "spin superradiance" research device and will be surrounded with low loss soft magnetic material. The design must support a high internal circulation current through the inductance of each resonator plate of the stack in order to create a strong magnetic field. Reference attached files.
Each stackable capacitive/inductive resonator plate needs to be 18 inches by 18 inches by some thickness between .05 inch to .25 inch with connections as shown such that they are stackable and can be connected to with #8 brass or copper screws or with brass or copper roll pins. The design is such that the inductive shape can be flipped over on every other resonator plate of the stack using an extra set of screw holes that are for pass through only. The disconnects are plated through holes. I have Gerber files of what the odd and even layers must look like and of what the screw disconnect holes must look like but you can adjust the dielectric materials, number of layers, fabrication methods, etc.
The design must be cheap enough to fabricate that you can find and verify that a fabrication company will make enough for a 2.5 inch high stack for no more than $10000.
Voltage min. and max.:
Minimum voltage 400VAC RMS at resonant frequency. Max voltage not higher than 5KV AC.
Energy density and corona resistance:
The desired energy density should be as high as you can get without fear of internal shorts or other problems during long term use. Dupont's Kapton CR specification says it can last 11 years at below 400 VAC so that is a starting point. Dielectrics must hold up to internal corona. Consider coated or embedded nano-alumina or silicon-dioxide to improve corona resistance.
Other materials can be used instead of Kapton CR but consideration should be given to corona resistance. Possible dielectrics are:
or many others.
Consider 3D printing or screen printing of capacitors with high K nano particles added.
Suggested fabrication considerations:
When there are very small sharp edges to conducting surfaces internal corona discharges ionizing micro pockets of air can damage the capacitor and cause premature failure. Therefore a vacuum press should possibly be used during fabrication and a method specified to seal the capacitors during/after the vacuum treatment to insure there are no internal voids where corona can develop. It is suggested that conductor thickness be plated on rather than etched away because the later leaves small sharp edges that encourage corona discharge and arcing. Consider 3D printing or screen printing of capacitors.
Circulation current and heat rise:
A stack 2.5 inches high should support a resonant circulation current of at least 5KA with no more than a 5 degree temperature rise above ambient lab temperature but more current max is better. If a high enough circulation current can be achieved then the 2.5 inch stack can possibly be divided up to make 2 or 3 of the next higher assembly.
The present design has an estimated resonant frequency of around 50-150KHz and that whole range is too high. A target frequency is 5KHz or anything lower. An acceptable frequency is 10KHz.
Contest win parameters:
must agree to provide all design files related to their design.
reliability of materials
corona development resistance
conformance to specified dimensions
must not infringe on active patents without approval/licensing
ease of import/shipment