The above source was built with COMP_PWM for an Afro30 ESC and bench tested on three motors that have had sync issues in some previous FW versions:
On 4S and using a servo tester, the motors were tested for sync loss as indicated by the red LED on the Afro30.No attempts were made to tune timing, default advance was used.
The LG LCD television failed after less than 10 years, the LCD backlight would not always start and it became a bigger problem each winter.
| AWG | Cond dia (mm) | CSA (mm^2) | R/km (Ω) | Imax |
|---|---|---|---|---|
| 2 | 6.5 | 33.6 | 0.513 | 241 |
| 3 | 5.8 | 26.7 | 0.647 | 209 |
| 4 | 5.2 | 21.2 | 0.815 | 180 |
| 5 | 4.6 | 16.8 | 1.03 | 156 |
| 6 | 4.1 | 13.3 | 1.30 | 135 |
| 7 | 3.7 | 10.5 | 1.63 | 117 |
| 8 | 3.3 | 8.37 | 2.06 | 101 |
| 9 | 2.9 | 6.63 | 2.60 | 87.4 |
| 10 | 2.6 | 5.26 | 3.28 | 75.6 |
| 11 | 2.3 | 4.17 | 4.13 | 65.4 |
| 12 | 2.1 | 3.31 | 5.21 | 56.6 |
| 13 | 1.8 | 2.62 | 6.57 | 48.9 |
| 14 | 1.6 | 2.08 | 8.29 | 42.3 |
| 15 | 1.5 | 1.65 | 10.5 | 36.6 |
| 16 | 1.3 | 1.31 | 13.2 | 31.7 |
| 17 | 1.2 | 1.04 | 16.6 | 27.4 |
| 18 | 1.0 | 0.823 | 21.0 | 23.7 |
| 19 | 0.91 | 0.653 | 26.4 | 20.5 |
| 20 | 0.81 | 0.518 | 33.3 | 17.7 |
| 21 | 0.72 | 0.410 | 42.0 | 15.3 |
| 22 | 0.64 | 0.326 | 53.0 | 13.3 |
| 23 | 0.57 | 0.258 | 66.8 | 11.5 |
| 24 | 0.51 | 0.205 | 84.2 | 9.93 |
| 25 | 0.46 | 0.162 | 106 | 8.59 |
| 26 | 0.41 | 0.129 | 134 | 7.43 |
| 27 | 0.36 | 0.102 | 169 | 6.43 |
| 28 | 0.32 | 0.081 | 213 | 5.56 |
| 29 | 0.29 | 0.064 | 269 | 4.81 |
| 30 | 0.26 | 0.051 | 339 | 4.16 |
Derived in part from data published by Wiremax.
A set of four Skywalker 40A ESCs were purchased for trial on a tricopter (3 on bird, one spare for testing). They cost about $15 ea incl shipping on eBay, and they appear to be genuine Hobbywing product.
Continue reading Hobbywing Skywalker 40A ESC – initial testing
Speaker cable and similar Figure-8 twin in various sizes is popular as RF transmission line, particularly with QRP operators, especially those operating portable in the field (eg SOTA activators). Indeed, SOTA seems to have triggered a revival in the use of these cables. With the large number of online recommendations, one could be forgiven for thinking that a dipole and feed line formed entirely from #24 speaker wire is the antenna of choice.
With that in mind, this article looks at the performance of Jaycar WB1702 speaker cable, 14×0.14mm conductors (#24) with PVC insulation, cost $0.50/m.
Matched Line Loss (MLL) is the loss or attenuation of a transmission line terminated in its actual characteristic impedance, and usually give for some length, eg dB/100′, dB/100m, dB/m.
One method that occurs in ham radio articles is to measure the input resistance of a resonant s/c or o/c stub, and to calculate MLL as 8.686*Rin/Zo/length dB/unitlength. (This is not the only method, or even a good one, but it is commonly used.)
Bench tested a DT750 on 3S, Afro30 with 2013-10-29_8c2cf42_comp_pwm, 11×4.5SF and Eagle datalogger. This motor is reported by some to be incompatible with SimonK.
Continue reading HK DT750 motor, Afro30 ESC and SimonK 8c2cf42/comp_pwm
G3TXQ has published (undated) a set of measurements on commercial windowed ladder line at Wet ladderline (accessed 10/01/14).
His measurements are of interest as there is a dearth of credible measurement data for these types of lines below 50MHz. Continue reading Windowed ladder line loss – G3TXQ
A new Hakko FG-100 arrived from China this week, the meter and pack of 5 sensors cost less than A$12 including post.
Continue reading Review of Hakko FG-100 soldering iron thermometer
This article describes a driver for flashing LEDs using a repurposed ESC.
