Owen – Page 99 – owenduffy.net

Accuracy of AIMuhf system – AIM865A vs AIM885Gx on a ferrite cored inductor

At Accuracy of AIMuhf system – AIM865A vs AIM882 vs AIM885 on a ferrite cored inductor I compared measurement of a small ferrite cored inductor on three ‘production’ releases of the AIM program.

Since then, AIM885A was released and it had problems as mentioned at AIM 885A produces internally inconsistent results.

Since then, AIM882, AIM885, and AIM885A have been pulled.

The developer advised on his support forum I’m sorry but version 885A has some problems. I’m working an update. In the meantime use the mature version AIM_865A.

Today, he posted a link to AIM885Gx (a declared beta release which presumably fixes problems in the pulled versions AIM882, AIM885, and AIM885A). Continue reading Accuracy of AIMuhf system – AIM865A vs AIM885Gx on a ferrite cored inductor

Last update: 26th December, 2015, 9:01 AM

Using a Pt100 RTD with my generic heating / cooling controller

Generic heating / cooling controller describes a bang-bang type thermostat based on a AtTiny25.

This article works up an example application using a Pt100 RTD sensor. Pt100 is the designation for a platinum (Pt) resistance temperature detector with nominal resistance of 100Ω at 0°. Pt has a nearly linear resistance / temperature characteristic and high accuracy. Continue reading Using a Pt100 RTD with my generic heating / cooling controller

Last update: 15th May, 2015, 5:45 PM

N2006P PID checkout #1

The N2006P is a inexpensive PID controller, typically for heating and cooling operations. There are lots of similar devices for under A$20 on eBay.

Above, the controller in a minimal test harness using a Type K Thermocouple for temperature sensing and 40A SSR mounted on a heatsink. (The SSR output should be protected with an MOV for inductive loads.) 480VAC 40A SSRs sell for as little as A$5 on eBay. Continue reading N2006P PID checkout #1

Last update: 5th May, 2015, 1:01 PM

Slot.it CA20Z build

The Slot.it CA20Z is Ford GT40 supplied as a ‘white’ kit which requires assembly and painting work.

Above is the part assembled body after painting with Tamiya X-7 acrylic. Continue reading Slot.it CA20Z build

Last update: 22nd April, 2015, 5:51 PM

Raspberry Pi 2 initial impressions

I couldn’t help myself… I bought a Raspberry Pi 2 (RPi2) to evaluate.

The RPi2 has 1GB of main storage (double that of the earlier RPi B+), and a 4 core 900MHz processor against a single core 700MHz process in the the RPi B+. Continue reading Raspberry Pi 2 initial impressions

Last update: 16th April, 2015, 1:18 PM

AIM 885A produces internally inconsistent results

Further to AIM 885 produces internally inconsistent results…

A new release, AIM885A appeared recently.

In the common theme of one step forward, two steps backwards, this version produces error popups when started.

The above popup appears twice when starting AIM885A. Just another symptom to undermine confidence in the system. It doesn’t make sense to me, and the program appears to otherwise start and run. Continue reading AIM 885A produces internally inconsistent results

Last update: 17th May, 2015, 6:57 PM

AIM 885 produces internally inconsistent results

AIM 882 produces internally inconsistent results and AIM 882 produces internally inconsistent results – more tests raised some issues with AIM882 software.

AIM885 has been released. Continue reading AIM 885 produces internally inconsistent results

Last update: 17th May, 2015, 6:57 PM

Accuracy of AIMuhf system – AIM865A vs AIM882 vs AIM885 on a ferrite cored inductor

This article builds on Accuracy of AIMuhf system – AIM865A vs AIM882 on a ferrite cored inductor by adding a measurement using AIM885 of the same test inductor.

Above is the test inductor. It comprises 6 turns of 0.5mm PVC insulated wire wound on a BN43-202 binocular balun core. Continue reading Accuracy of AIMuhf system – AIM865A vs AIM882 vs AIM885 on a ferrite cored inductor

Last update: 26th December, 2015, 9:01 AM

AIM885 Refer To Antenna checkout

Among the New features in version 885 is Fixed “Refer to Antenna” function... so lets check it out.

The AIMuhf was calibrated using the supplied SOL components and AIM885.

Direct measurement

Above is a sweep of a 1.05m length of Belden 8262 (RG58C/U) cable (with o/c termination) attached to the AIMuhf. Continue reading AIM885 Refer To Antenna checkout

Last update: 26th December, 2015, 9:01 AM

A new impedance calculator for RF inductors on ferrite cores

Some time ago I published a calculator for estimating the impedance of RF inductors on toroidal ferrite cores (Calculate ferrite cored inductor).

The calculator (input form above) use the core dimensions and complex permeability as the basis for calculation.

There are some popular cores that are not simple toroids and so not suitable for direct use with that calculator. For these cores, a practical method is to measure the inductance constant Al (inductance of 1 turn in nH) at low frequency (where µ=µi), and using the µ’,µ” characteristic from the datasheets, to calculate the impedance at the desired frequency. Note that µ’,µ” are usually frequency dependent for ferrite materials. Continue reading A new impedance calculator for RF inductors on ferrite cores

Last update: 26th March, 2015, 10:38 AM