My Light Diagram

There are general-purpose spectrum analysers, and then there are specialised ones. What kind of a spectrum analyser do you need? The answer to this question basically depends on the maximum frequency range that you want to measure, after including the harmonics and intermodulation products of the wanted signals. Although you can get a lab-grade oscilloscope that can analyse low audio frequencies up to microwave, this is overkill if you are going to use it with audio equipment. On the other hand, if you are working on very high frequencies, you might need an analyser that has a resolution good enough to differentiate between the smaller frequencies. N9344C handheld spectrum analyser Some new releases in this space are: 1. Tektronix MDO4000 mixed-domain oscilloscope, which is claimed to be the world’s first oscilloscope with built-in spectrum analyser. 2. R&S FSW-K91ac signal and spectrum analyser, which supports the new IEEE 802.11ac WLAN standard. 3. Anritsu MS2830A + OML MxxHWD, w...

In almost on all the 132 kV & 220 kV Sub-stations two sets of 110 V (for protection) and one set of 48 V (for carrier communication) lead Acid station batteries along with battery chargers are installed. The battery charging equipment comprises of a float charger and a boost charger. Stabilization  output voltage is provided in the float charger to float the battery at the correct level. The battery can be boost charging after a prolonged mains failure by the boost charger. These chargers have been provided protection for under voltage DC & earth fault. DC Board is installed to feed various essential DC load from a separate feeder. Recommended specific gravity of cells at 27 0 C (electrolyte temp) should be 1.210 ± 0.005. Actual temp should be measured in the electrolyte of the cell. If the temp is different than 27 0 C the correction ± 0.0007/ 0 C change in temp. should be made in sp. gr. (Subtract for temp. below 27 0   C  and add f...

5.2 Conditions for induced e.m.f. in a conductor This can only take place in the conductor when 1. there is relative motion between conductor (coil) and magnet (fig. 5.2.1b and fig 5.2.1c) 2. magnetic field lines are being cut by the conductor 3. cutting of the field lines must be perpendicularly to get maximum effect 4. the direction of e.m.f. depends on the direction of relative motion between conductor and direction of magnetic field lines (approach, fig. 5.2.1b and retreat, fig 5.2.1c) Conditions for induced e.m.f. in a conductor Summarizing, relative motion is needed between a magnet and a coil to produce induced e.m.f.s.  The induced e.m.f. increases when the relative velocity increases and when a soft iron core is used inside the coil.  The soft iron core concentrates magnetic field lines.

  Apple Inc. has started an iPhone trade-in program in its stores, letting owners sell older handsets back to the company in exchange for credit toward a new model.  Apple’s U.S. retail outlets are now accepting devices, said Amy Bessette, a spokeswoman for Apple. The initiative is starting just before the next iPhone’s debut on Sept. 10. While Gazelle Inc. and wireless carriers such as Verizon Wireless and AT&T Inc. already buy used handsets, this is the first program run by the iPhone maker at its stores. By buying old phones, they’re aiming to spur new device sales by helping cover the cost of buying the latest smartphone. Apple is teaming up with Brightstar Corp., a mobile-phone distributor, to run the operation, people with knowledge of the plans said in June. “IPhones hold great value so Apple Retail Stores are launching a new program to assist customers who wish to bring in their previous-generation iPhone for reuse or recycling,” Bessette said. “In addition to he...

 Sony Computer Entertainment Inc . (SCEI) announced that cumulative sell through for the PlayStation 4 ( PS4 ) worldwide has surpassed 2.1 million units as of December 1, 2013. The number includes the 700,000 units sold through in Europe and Australasia launching on November 29. The PS4 system became available on November 15 in the United States and Canada and on November 29 in Europe, Australasia and Latin America and is now available in 32 countries globally. “ PS4 delivered the best launch in PlayStation history with the North American release and we’ve continued this incredibly successful start in Europe, Australasia and Latin America,” said Andrew House, President and Group CEO, Sony Computer Entertainment Inc. “Demand remains incredibly strong and continues to overwhelm the supply worldwide, but we are diligently working to meet those growing demands and to deliver additional PS4 units to our retail partners throughout the holiday season.  We are extremely grateful f...

The 4 - 20 mA signal is an extremely popular signal specification in instruments. The 4 to 20 mA signal provides "live zero" function. i.e. in the event of a wire break, the signal drops to zero mA. This can be used to detect wire break or sensor failure. This is a crucial advantage of the 4 to 20 mA format. Being a Current signal, it is also less susceptible to external interference. The 4 to 20 mA format works by varying the resistance to a constant source voltage. The sensor consists of a transistor which regulates the current passing through it in accordance with the measured value. Sensors which use this format can be categorized into active and passive transducers. Active transducers are devices which can provide the system voltage as well as regulate the current. Passive devices require an external voltage and only regulate the current. Another advantage of this 4 to 20 mA format is that it can be easily converted into a voltage signal by means of a res...

This very cool American Standard Stratocaster came in for a clean and a restring—normally a very straightforward job. However, it had been in storage for several years in a fairly humid environment and a lot of the metalwork, including the electrics, had become somewhat corroded. It actually looks OK from that distance. Here are a few close-ups. In addition to the dirt and grime, you can see that many of the screws have rusted quite badly. A quick test also revealed that the pots were scratchy, the switch was not working correctly and the output jack was making a lot of crackling noises. A look down the neck shows corrosion on the frets, so these will need a bit of a clean and polish too. Oh and... is that… blood? The only way to deal with this is to dismantle it, but before I do that I’m going to take some measurements since it was actually playing pretty nice and I don’t want to change that if I can help it. Measuring the saddle positions:     And the pickup heights: First...