Mutchus

When it comes to your surround sound or home theater system, the quality of your speakers can really make or break the overall experience. Good quality speakers are one of, if not, the most important components when it comes to your home theater and surround sound system.  You need to take action from the very beginning in order to make sure that you are not getting substandard speakers for your entertainment system whether your surround sound system is going to be used for your television viewing, home theater, music enjoyment, or to enhance your gaming experience on your personal computer the quality of the speakers will have a huge impact on how much you enjoy your system. The problem is that most people do not even know where to begin when it comes to selecting and purchasing speakers. There are a few guidelines you can follow when making your decisions about speakers that will help you make better buying decisions in order to get higher quality speakers (budget allowing of cou...

The PIC32MX250F128B has a myriad of peripheral features that makes this cheap little 28-pin 32-bit microcontroller extremely powerful. However, it does lack a digital-to-analog converter (DAC). A simple approach to digital-to-analog conversion is to use one of the PWM channels and then to use an RC low-pass filter at the output. However, there is another neat little feature of the device that can be exploited or rather utilized to obtain a rather crude DAC – the analog comparator module. Rather, the analog comparator reference module. The PIC32MX250F128B contains an internal voltage reference module that was created to be used as a reference voltage for the internal analog comparator module. However, it does allow you to output this reference voltage to an output pin. Analog voltage output with digital control? Sounds like a DAC. The voltage reference module is built off of a 16-tap resistor ladder network with two selectable ranges – from 0 to 0.67 CVREF or from 0.25 to 0.75 CVREF. CV...

I don’t often build more than one of the same pedal. In fact, I think the only one I’ve ever built twice was the Minimixer (http://diystrat.blogspot.com/2008/08/two-channel-mini-mixer.html), but I don’t think that even counts as a pedal. Christian over at Black Sunshine Media was so enamoured with the Volumizer, however, that I offered to build one for him too. I also took the opportunity to do a better blog post about it, since at the time of doing the original one, I kind of skimmed over some important points. Firstly, some background. The Volumizer is my clone of an MXR Micro Amp, the schematic of which can be found at General Guitar Gadgets. There is basically no difference between my circuit and the one shown there, apart from the layout and possibly a couple of very slightly different parts (due to a lack of local availability). This pedal is a great little pre-amp, which boosts volume and nothing else. It’s nice and clean and only provides distortion if you use it to drive some...

Anyone who has designed circuits using the 555 timer chip will, at some time have wished that it could be programmed for longer timing periods. Timing periods greater than a few minutes are difficult to achieve because component leakage currents in large timing capacitors become significant. There is however no reason to opt for a purely digital solution just yet. The circuit shown here uses a 555 timer in the design but nevertheless achieves a timing interval of up to an hour! The trick here is to feed the timing capacitor not with a constant voltage but with a pulsed dc voltage. The pulses are derived from the un smoothed low voltage output of the power supply bridge rectifier. The power supply output is not referenced to earth potential and the pulsing full wave rectified signal is fed to the base of T1 via resistor R1. A 100-Hz square wave signal is produced on the collector of T1 as the transistor switches. The positive half of this waveform charges up the timing capacitor C1 via ...

Joe Collier and Kai Wei Tang created a concept cell phone Light Phone size of a credit card, which is connected to the main cell phone and has only the function calls. 

This circuit can control the direction of a DC motor., It has many applications that are necessary to operate a motor in both directions, clockwise and counter-clockwise (forward and backward). One way to accomplish this is to start the engine in a circuit arrangement of transistors called H-bridge. H bridge is an electronic circuit which enables a voltage is applied across a load in either direction. This circuit is often used in robotics and other applications to allow DC motors to become bi-directional. H-bridge Control the Direction of Rotation for DC motor Circuit Diagram List of components PARTS LIST R1, R2, R3, R4 220Ω R5, R6, R7, 1K Ohm D1, D2, D3, D4 1N4001 D5, D6 LED Q1, Q2 2SD313 Q3, Q4 2SB507 PB1, PB2 switch M1 12V DC MOTOR In this circuit usually PB1 and PB2 are open. Thus, the bases of the transistors are grounded. Hence Q3 and Q4 are turned on, Q1 and Q2 are turned off. The voltages at both terminals of the motor is the same and thus the engine is switched off. Similarly...

You may think the name of this amp came about because of its size, but in fact it was simply because of what was printed on the wood used to make the box. You see, it was made with the thin wood from a Chiquita banana crate. Incidentally, this amp has no connection whatsoever to the wonderful Erlewine (and later Hondo) Chiquita travel guitar, as featured on Back to the Future, or the little amplifier that was sometimes included with it. In fact I didn't even know about that model name until years after I made this. Apologies for any confusion. After finishing the DIY Strat, I decided I needed a little amp. I had next to no money to actually buy one, so I thought I might as well just make one. After a bit of research online, I settled on a simple audio amp using a TDA2030A. Let me just state right now that this was back in 2000, so the amount of information available online at the time was much more limited. I’m sure there are plenty of really good circuits available for fantastic m...

We live in a world that is constantly changing and evolving. We see it every time we buy a new car, a new television, or a new computer. We see it every other month when the iPod is putting out a new an improved model that offers more features, more disk space, and more everything, in a smaller package (well not since they added video but until then, the gadgets were getting smaller while the features were growing exponentially). The truth of the matter is that technology seems to be advancing at a rate that is nearly impossible to keep up with. That being said, you can quite literally drive yourself insane by trying to keep up with the pace of modern technology. What you need to do in order to maintain proper sanity is decide on a level of technology that you are comfortable and confident with and go with it until it is time (by either necessity or desire) to upgrade. You do not have to be the first to purchase the latest and greatest in software and gadgetry (this has become my mantr...

This is an introduction to PLC logic . You can use PLC logic to build PLC programs with simple electrical circuit diagrams. In this article, I will use combinatorial logic to build the functionality of a PLC program. And to get as close as possible to real a PLC programming language like ladder logic, the PLC logic in this article will be  contacts and relays in an electrical circuit . The first PLC program you will be building will be a very simple one. You will be using combinatorial logic to build your PLC program. The reason for this is that, a PLC program is really just logic . Everything in a PLC has two states, just like in digital logic. In logic the two states are called FALSE and TRUE. Sometimes these two states are referred to as “0” and “1”. Those two states are referred to as the numbers 0 and 1, so that we can use the them in binary numbers. Since the PLC works with two states only, it makes sens...

With the amount of equipment in home entertainment centers today the need to be able to vary the gain of the audio or video signal is needed. I found this particular circuit helpful when used in conjunction with the Universal Descrambler and a Stabilizer circuit I built for making copies of video tapes. It not only allowed me the ability to fine tune the video strength it also helped me increase the recorded audio which typically becomes poor when making tape copies. Circuit operation is straight forward for amplifier circuits. The second channel for the audio amplifier is made up of the same components except the other half of IC1 is used. Pin 6 & 5 are inputs and 7 is the output. The Audio/Video Distribution Amplifier  Circuit Diagram

 Hi-Current Capability Integrated Amplifier - Harman Kardon PM640 – Schematic RMS Power Output > 35W Power Supply > AC120V – 60Hz Weight > 6.4kg SCHEMATIC PWB CLICK ON THE PICTURES TO MAGNIFY

Christe is a very well known projector manufacturer. The opening of The Atlantic in Dubai was, in fact, done using the company's projectors. They are at Gitex to showcase some of their new products this year. One of them is the Christie J series range, a compact (in its class) projector solution that combines the best of the company's innovations into one affordable package (if ever these things can be affordable). The most interesting feature of the projector is the Christe Twist, a hardware-based pixel mapping technology that can adjust any image onto the surface it is projecting on, and stitch multiple images into one seamless image. An example is below. The Christe J series is also fitted with the 3-chip DLP platform along with 22,000 lumens of Xenon brightness to help deliver proper color accuracy and clean, crisp images. The J series comes in various low to high-end models, with the Christe Roadster HD20K-J featured above carrying a price tag of USD 80,000.

Anyone who has designed circuits using the 555 timer chip will, at some time have wished that it could be programmed for longer timing periods. Timing periods greater than a few minutes are difficult to achieve because component leakage currents in large timing capacitors become significant. There is however no reason to opt for a purely digital solution just yet. The circuit shown here uses a 555 timer in the design but nevertheless achieves a timing interval of up to an hour! The trick here is to feed the timing capacitor not with a constant voltage but with a pulsed dc voltage. The pulses are derived from the un smoothed low voltage output of the power supply bridge rectifier.  Extend Timer Range Circuit  The power supply output is not referenced to earth potential and the pulsing full wave rectified signal is fed to the base of T1 via resistor R1. A 100-Hz square wave signal is produced on the collector of T1 as the transistor switches. The positive half of this waveform c...

Feasibility Find out if the current user needs be satisfied given the available technology and budget? Requirements Analysis Find out what system stakeholders require from the system Requirement definition Define the requirements in a form understandable to the customer Requirement specification Define the requirements in a form understandable to the customer

 Fig. 1 - A typical high-voltage half-bridge section, using the IR2110 driver (Click image to enlarge)  Fig. 2 - A typical high-voltage full-bridge section, using two IR2110 drivers (Click image to enlarge) Whenever I get a message or an email or a comment regarding unsuccessful bridge circuits, it’s usually along the lines of no output being observed, the MOSFETs getting hot, or everything just getting damaged or blowing up. When I was in the preliminary stages of bridge design, I also had repeated failures. I had circuits blowing up. I had circuits just not working, no matter what. I’ve written on my blog about one such experience of mine. You can read it here: http://www.blogspot.com/2016/10/magic-of-knowledge.html In this article, I’ll talk about the first things you should do if your attempts at designing a bridge circuit have gone up in smoke or if you’re designing a bridge circuit and want to ensure everything has been done properly. Another thing I should mention is ...