by Steven Keeping:
Such is the popularity of DC-to-DC voltage converters (“switching regulators”)––due to their high efficiency across wide input- and output-voltage ranges––that chip makers have focused a lot of research dollars on squeezing the essential components of the devices into modules. These modules typically include pulse-width-modulation (PWM) controllers and switching elements in a single, compact package, easing the design work for the engineer.
However, until recently, it has proven difficult to include the energy-storage device (the inductor) inside the package. This has dictated that the engineer must specify, source, and design-in the inductor as a peripheral component, adding complexity and consuming board space. Now, a new generation of high-frequency switching regulators has enabled the use of smaller inductors enabling the devices to be housed inside the component vendor’s package.
The Advantages (and Drawbacks) of DC-to-DC Voltage Converters with Integrated Inductors – [Link]
Vishay Intertechnology introduced a new automotive-grade IHLP® low-profile, high-current inductor with an industry-high continuous operating temperature range to +180°C. Offered in the 2525 case size with a low profile of 3.0 mm, the new Vishay Dale IHLP-2525CZ-8A provides a wide range of inductance values from 0.47 µH to 22 µH.
With a frequency range up to 1 MHz, the AEC-Q200-qualified device released today serves as a high-performing, space- and power-saving solution for voltage regulator modules (VRM) and DC/DC converters in high-temperature automotive applications. End products include engine and transmission control units, diesel injection drivers, entertainment and navigation systems, noise suppression for motors, windshield wipers, HID and LED lighting, heating and ventilation blowers, and power seats and mirrors.
New Vishay Intertechnology Automotive-Grade Low-Profile, High-Current Inductor Offers Continuous High-Temperature Operation to +180°C – [Link]
After finishing my last project – “Simple LC meter“, there were some discussions in the forum I am a member of, that ability to measure electrolytic capacitors would be very useful in this type of device.
I searched the Web and found a very cute project named LCM3 on this Hungarian site: hobbielektronika.hu . I love Hungarian rock since my school days, but I don’t know a word in Hungarian . So, I searched the Web again, this time for this specific project and found a Russian forum where the project was discussed in details and I got more useful information about parts, settings and so on.
Advanced LC meter – [Link]
The first approximation is based on a modification of an expression developed by Wheeler; the second is derived from electromagnetic principles by approximating the sides of the spirals as current-sheets; and the third is a monomial expression derived from fitting to a large database of inductors (and the exact inductance values).
Single layer Planar spiral coil inductor calculator – [Link]
This video shows one method I use to wind toroidal inductors and transformers. The real trick is often how to hold the toroid core while doing the winding of the wire. The plastic toroid fixture shown is available from http://www.qrpme.com. I also give a few details on how to strip the enamel insulation, and then test the inductor when it is complete. There are many, many useful websites that contain toroid data, including composition, type, size, materials, winding factors, calculators, and more
How to wind a toroid inductor – [Link]
The identification for the Amidon toroids consists of one or two letters (T=toroid and FT=ferrite toroid), followed by a number (for ex. T50), which represents the outer diameter dimension expressed in 0,1 inches, followed by a separation mark (dash, dot, stroke), followed by another number indicating the frequency mixture and the frequency range at which it would be recommended to use the toroid.
It should be taken in account that a toroid with a X declared frequency will be able to operate with fairly good performances even at 10 times higher frequencies and only the A factor will decrease.
The iron powder toroids are colored according to their mixture; the first color covers three sides and the second color the remaining side.
Simple software to calculate the air core coils, the most widely used in RF circuits and may use the software to determine the data to build a coil, knowing that the inductance of this coil. The software will give the result of how many turns will be required to achieve certain inductance value, and provides the wire diameter … In addition has a table with wires AWG mm thick.
All I do is use the LM311 square wave output as pulses to a 16bit counter, and another 100mS periodic timer to count how many pulses per 100mS interval, to calculate the oscillation frequency. BTW, the PIC32 is running off a 16MHz crystal. I average the results from 5 consecutive readings, so I have a 0.5second measurement repeat rate. Good enough. It seems to be accurate enough for my needs, which is basically identifying components that I salvage, or coils that I wind myself.
LM311 oscillator based LC meter – [Link]
The LTM®4600 is a complete 10A switchmode step-down power supply with a built-in inductor, supporting power components and compensation circuitry. With high integration and synchronous current mode operation, this DC/DC µModuleTM delivers high power at high efficiency in a tiny and low profile surface mount package. Supported by Linear Technology’s rigorous testing and high reliability processes, the LTM4600 simplifies the design and layout of your next power supply.
- 15mm x 15mm x 2.8mm LGA with 15°C/W θJA
- Pb-Free (e4), RoHS Compliant
- Only CBULK Required
- Standard and High Voltage:
* LTM4600EV: 4.5V<=VIN<=20V
* LTM4600HVEV: 4.5V<=VIN<=28V
- IOUT: 10A DC, 14A Peak
- Parallel Two µModules for 20A Output
LTM4600 – 10A switchmode step-down power supply with a built-in inductor – [Link]
This project shows how to build a Inductor & Capacitor Meter based on ATMEGA32. The result is shows on LCD. The way it works is simple, you change an oscillator frequency with the part you want to find is value and by doing some maths you calculate the unknown part value. Check source code and schematic on the link below.
Inductor & Capacitor Meter (LCMeter) – [Link]
nico from microblog.routed.net writes: I have been very busy at the lab lately, too busy to update ublog regularly, and this set of formulas from Gamma Instruments has saved me a bit of trouble. Several air core inductor designs are outlined which allow you to make your own custom inductor, within reason, if you need to test something and you don’t have the part on hand. Typically, the inductance values will be modest, however, it is much easier to make an inductor yourself than a reasonable capacitor. Just think of all of the folding!
Notes on air-core inductor value computation – [Link]