Fullscreen HTML5Med Res (??MB)HTML4

Notes & Errata Timer For Fans And Lights (August 2012): do not wire the unit up as shown in Fig.1(c) on page 65, with a load from the “Asw” terminal to Neutral. This will destroy the unit. If you need to wire up a fan and light, connect them in parallel between the “Aload” terminal and Neutral. 230V 10A Universal Motor Speed Controller, February 2014: a 100nF MKT polyester capacitor was omitted from the circuit and parts list (there should be five, not four). It connects between the wiper of VR3 (pin 2 of IC1) and ground. The PCB pattern and the PCB overlay published in this issue are correct. The capacitor is immediately adjacent to CON10. Mini Entertainment Unit, February 2014: the modified version of the MiniReg Adjustable power supply (pages 46 & 47) should specify a higher-rated diode for D1, to match the current rating of the LM338 adjustable 3-terminal regulator. We suggest a BY229 fast switching diode. It has low forward voltage and a current rating of 8A. It comes in a TO-220 package which can be mounted upright on the PCB. Stereo Echo & Reverb Unit, February 2014: on page 35, the article states that this unit can be built from a delay unit kit (Jaycar KC-5506). Unfortunately, this kit is for the delay unit from December 2011 rather than November 2013 and is not suitable. SILICON CHIP can supply the PCB, programmed microcontroller and some of the parts for this project; see our Online Shop ad or website for more details. would be difficult to incorporate in a dumb dryer. In particular, the drum and dryer are typically powered by a single-phase induction motor and these are usually not possible to reverse, even if you have access to the internal wiring. Most modern dryers do have a 2-way switch to control the power level and that is probably all that is required to protect delicate fabrics. Humidity sensing of the exhaust air is a good idea but you would need to ensure that the humidity sensor never became clogged by the residual lint which is always present. source; in other words, “look” just like a battery under charge so that cut-off points etc can be checked. (I. M., via email). •  In the past, we have built several prototypes of what could be called “adjustable loads” or adjustable current sinks but they did not make it to publication because of various problems with thermal stability and supersonic oscillation. In each case, they were based on power Mosfets. It is a tricky design exercise, made more difficult if the design has to cope with a wide range of battery voltages and load currents. Battery load tester wanted MPPT controller needs RF suppression In May 2011 you published an “electronic solar panel” for want of a better name, in other words a supply that acted like a solar panel for testing solar regulators. I am wondering if you have ever produced what can only be called an “electronic battery” for testing battery chargers. I specifically refer to lithium-ion chargers which have tight requirements for voltage sensing in particular. What I envisage is an active load which will sink a known and adjustable current while presenting a known and adjustable terminal voltage to the I do realise that the MPPT Solar Charge Controller from the February 2011 issue and its update in the March 2012 issue have been around for awhile but I need to ask this question anyway. While it works exactly as it should, my problem with it is the amount of switching noise it generates. It creates 31.5kHz birdies from the bottom end of the AM broadcast band to at least 7.5MHz. This is not good for amateur radio use! I have tried some brute force filtering (a Pi filter with a 10mH choke and two 10,000µF capacitors on the input 110  Silicon Chip and output of the controller) but so far I have been unsuccessful in making any difference to the noise level. Any advice pointing me in the right direction would be much appreciated. (A. B., via email). •  While we have not tried it, the metal case could be connected to the battery negative screw terminal using an eyelet screwed to the box and a wire lead. Then use ferrite suppression clip-on sleeves over the solar panel and battery wiring. The Jaycar LF1290, LF1292 or LF1294 (or similar) ferrite suppression sleeves could be used. Questions on ADSB collinear antenna I really liked your down-to-earth article on ADSB antennas in the September 2013 issue and I would like to ask a few questions. Was either antenna tested for performance and return loss etc? If so, what were the results? What is the anticipated bandwidth of each type of antenna design? What is the dielectric effect of putting the 1090MHz collinear in PVC piping? What tools would be needed to tune the antennas, if needed. I’d like to get optimum performance from the collinear design. (J. G., via email). •  The antennas were only checked for signal pick-up. No other parameters were checked. We would not expect any dielectric effects from the PVC piping and no effect on signal pickup. Countless antennas these days are housed in some sort of plastic sheathing and it does not effect pick-up. Unless you have equipment to measure signal pick-up such as a spectrum analyser, it would be difficult to tune or optimise the antenna. MPPT controller only designed for solar panel I recently completed the MPPT solar panel charger for use with a small camper van and all works fine. It is the upgraded second version featured in the March 2012 issue. However, the rest of the electrical system needed an overhaul. A regulated mains power supply is set to produce 13.3V and this is permanently connected to the battery in normal use. Clearly, this system will never be able to fully charge the battery continued on page 111 siliconchip.com.au