Posts

Showing posts with the label For

Great Brands for Good Prices on Auto Sound Systems

If you are one of the many people across the country considering a new auto sound system, there is a great deal of good news. First of all, it is very possible to find a good bargain on a nice sound system for your car, truck, or SUV if you are willing to shop online and install the system yourself. The problem often lies not in the cost of the system but the price of the installation. However, the cost of installation is well worth the dollar amount for many of us who really have no clue what to do as far as a project of that scope goes. I for one am among the electronically challenged and not really willing to risk my dash board for an experiment in frustration and failed electronics. That being said, there are many who are either perfectly and wonderfully capable of installing a nice auto sound system or are fortunate enough to know someone or someone who knows someone who is. Gaining Up, finding a great bargain online is probably the best way to go-provided you've actually been...

Electrical Isolation For I2C Bus Circuit Diagram

Image
When the SDA (Serial DAta) lines on both the left and right lines are 1, the circuit is quiescent and optoisolators IC1 and IC2 are not actuated. When the SDA line at the left becomes 0, current flows through the LED in IC1 via R2. The SDA line at the right is then pulled low via D2 and IC1. Optoisolator IC2 does not transfer this 0 to the left, because the polarity of the LED in IC2 is the wrong way around for this level. This arrangement prevents the circuit holding itself in the 0 state for ever. As is seen, the circuit is symmetrical. So, when the SDA line at the right is 0, this is transferred to the left. The lower part of the diagram, intended for the SCL (Serial CLock) line, is identical to the upper part. Electrical Isolation For I2C Bus Circuit diagram : Electrical Isolation For I2C Bus Circuit Diagram Resistors R1, R4, R5, and R8, are the usual 3.3 kΩ pull-up resistors that are obligatory in each I2C line. If these resistors are already present elsewhere in the system, they...

Hacking Car Wipers for Easy Control

Image
How do you want to have your wipers become more intelligent? In this way, they could remember how frequent you need to use them. But of course, this will need the help of an ATmega8L microcontroller. When you need to activate the wiper, you just press the button and it will run in one course. There is a 45 seconds waiting time that if you do not press the button, it will go on standby while telling itself that only one course is needed. The system will activate the wiper again if the button is pressed before 45 seconds. The good thing is that it will remember the interval when you pressed the button. Click here to visit the project page.

Fan Speed ​​Control for Temperature Circuit Diagram

Image
With this simple circuit that you will be able to control the speed of a DC fan according to the temperature measured by a temperature sensor. It is an ideal accessory for your projects that require cooling that are not constant.  This simple design allows precise speed control of motors, fans, and blowers, proportional to the temperature. An NTC thermistor (R1) is used as temperature sensor. A circuit optional was added to remotely monitor the operation of the fan and to allow some kind of indication of the approximate speed by increasing the brightness of an LED.  Fan Speed ​​Control for Temperature Circuit Diagram The R5 must be configured to allow the engine just starting to run at the desired temperature. Any 6K8 between the NTC thermistor 22K can operate provided that the R2 value is one tenth of the thermistor. R6, R7 and D1 are optional: R7 obligation is adjusted until the LED glow dimly when the engine is just running. Parts List R1 15K @ 20 ° C NTC Thermistor (See No...

Basic Components for a Home Theater

Image
Many people never bother looking into purchasing a home theater through sheer fear of the decisions that may need to be made in the process. Many among these aren’t even sure of exactly which components are included in a home theater or which ones are needed in order to create an effective and entertaining home theater. For this reason, many people simply do not bother going through the process of looking at their options when it comes to these wonderful systems on the market today much less ever bother actually purchasing one. Basic Components for a Home Theater If you are one of the many who has experienced some degree of confusion when it comes to the individual parts and pieces that are included in a home theater system and what they do, hopefully you will gain a better understanding once you’ve finished reading. The first thing to understand is that there are varying degrees when it comes to home theaters. The following components are the makings of a very basic home theater that...

Project of Balanced Output Board For The Stereo DAC

Image
This add-on board is designed to provide a pair of balanced audio outputs for the High-Quality Stereo DAC (Digital to Analog Converter). Two 3-pin male XLR connectors are used for the new outputs and they can either replace or augment the existing unbalanced outputs without affecting their performance. Balanced audio is used in recording studios and on stage because of its improved noise immunity. Picture of the project:      This is due to the fact that the signal is sent differentially (ie, as two signals 180° out of phase) and then converted to a single-ended voltage signal at the far end. If any noise is picked up in the cable, it affects the two out-of-phase signals equally so that when the signals are subsequently subtracted, most of the noise is eliminated. Parts layout: In addition, the DAC’s performance at the balanced outputs generally exceeds that of the unbalanced outputs, although only by a small margin. The signal-to-noise ratio, frequency response and chann...

Vocal Adaptor for Bass Guitar Amp

Image
These days, music is a major hobby for the young and not-so-young. Lots of people enjoy making music, and more and  more dream of showing off their talents on  stage. But one of the major problems often encountered is the cost of musical equipment. How many amateur music groups sing through an amp borrowed from a guitarist or bass player?  This is where the technical problems arise not in terms of the .25” (6.3 mm)  jack, but in terms of the sound quality (the words are barely understandable) and volume (the amp seems to produce fewer decibels than for a guitar). What’s more, unpredictable feedback may cause damage to the speakers and is very unpleasant on the ear. This cheap little easy-to-build project can help solve these technical problems. A guitar (or bass guitar) amplifier is designed first and foremost to reproduce the sound of the guitar or bass as faithfully as possible. The frequency response of the amp doesn’t need to be as wide or as flat as in hi-fi (p...

An LCD Clock Kit Suitable for Beginners with Open Source Arduino Firmware

Image
Simpleclock is an easy to assemble attractive 4-digit 7-segment LED display clock with temperature and alarm function. It is available in three display colors: Red, Blue and White. It comes as a kit of through-the-hole parts and can be soldered by any person with basic soldering experience. An attractive acrylic stand is included. [ ]

A Doorbell for the Deaf

Image
This circuit provides a delayed visual indication when a door bell switch is pressed. In addition, a DPDT switch can be moved from within the house which will light a lamp in the door bell switch. The lamp can illuminate the words "Please Wait" for anyone with walking difficulties.  A Doorbell for the Deaf Circuit Diagram : Notes : The circuit uses standard 2 wire doorbell cable or loudspeaker wire. In parallel with the doorbell switch, S1, is a 1N4001 diode and a 12 volt 60mA bulb. The bulb is optional, it may be useful for anyone who is slow to answer the door, all you need to do is flick a switch inside the house, and the bulb will illuminate a label saying Please Wait inside the doorbell switch or close to it. The double pole double throw switch sends the doorbell supply to the lamp, the 22 ohm resistor is there to reduce current flow, should the doorbell switch, S1 be pressed while the lamp is on. The resistor needs to be rated 10 watts, the 0.5 Amp fuse protects agains...

Regulator for Three Phase Generator

Image
This regulator was designed for use with a  generator with a higher output voltage. This  type of generator can be found on some boats  and on vehicles for the emergency services.  They are really just an adapted version of the  standard alternator normally found in cars.  The field winding is connected to the 12 V  (or 24 V) battery supply, whereas the generator winding is configured for the AC grid  voltage (230 V or 115 V). This AC voltage now  has to be kept stable via the 12 V field winding. Although it’s perfectly possible to use a  switching regulator for this, we deliberately  chose to use the old and trusted 723. Circuit diagram : Regulator for Three-Phase Generator Circuit Diagram The generator is a three-phase type, with the  field winding rated for 12 VDC. The output voltage of the generator depends on its revs  and the current through the field winding.  Since the output voltage is relatively high, it  is fed via opto-couplers to the 723, which is  used in a standard co...

Pump Controller For Solar Hot Water System

Image
This circuit optimises the operation of a solar hot water system. When the water in the solar collector is hotter than the storage tank, the pump runs. The circuit comprises two LM335Z temperature sensors, a comparator and Mosfet. Sensor 1 connects to the solar collector panel while Sensor 2 connects to the hot water panel. Each sensor includes a trimpot to allow adjustment of the output level. In practice, VR1 and VR2 are adjusted so that both Sensor 1 and Sensor 2 have the same output voltage when they are at the same temperature. The Sensor outputs are monitored using comparator IC1. When Sensor 1 produces a higher voltage than Sensor 2, which means that sensor 1 is at a higher temperature, pin 1 of IC1 goes high and drives the gate of Mosfet Q1. This in turn drives the pump motor. IC1 includes hysteresis so that the output does not oscillate when both sensors are producing a similar voltage. Hysteresis comprises the 1MO feedback resistor between output pin 1 and non-inverting input...

A Nokia Worth Attention But Not for Why Youd Think

Image
The new Nokia Lumia 1020 smartphone is worth paying attention to, but not for the reason you've heard. The key figure in Nokia's ads and marketing is 41 -- as in, the number of megapixels of the Lumia's camera. That's a crazy number, triple what any other manufacturer except Nokia itself with its 808 PureView (which runs the old Symbian operating system, as opposed to the Lumia's Windows Phone 8) has ever put into a smartphone. The thing is, the number of megapixels, while important, is vastly overrated in evaluating smartphone cameras. Where it matters most is in maintaining sharpness at large sizes. Now, when was the last time you printed a poster from a photo taken on your phone? In fact, photos that pixel-dense can be a problem in real life; they take up lots of storage space and don't lend themselves easily to sharing. So now that we've disposed of that, here's what's important about the 1020: the camera. Nokia has included several feature...

Sawtooth to Triangle Converter for Oscillator Circuit

Image
This wave shaper needs an input saw that goes from Vss to (ideally) Vdd. It works well with the 4069 VCO designed by René Schmitz. Any saw will work as long as the wave is centered halfway between the rails. It works as follows: The upper set of 2 linear mode gates provide an inverted and noninverted copy of the saw. The 3 logic gates at the bottom provide a sort of comparator that switches at halfway between the rails.   Sawtooth to Triangle Converter for Oscillator Circuit Diagram The 4007 provides 2 P-MOSFETs that alternately select the inverted or noninverted saw signal depending on where the saw is in it's cycle. This causes the ramp to reverse directions every half cycle. Any imperfection in the saw will show up in the resulting output. The linear mode gate furthest to the right provides soft clipping that turns the triangle wave into something like a sine wave. It sounds like it has fewer harmonics than the triangle. To use with FatMan sawtooth output: Power all IC...

SW Converter for Digital AM Car Radio Circuit Diagram

Image
SW Converter for Digital AM Car Radio Circuit Diagram This circuit is purposely presented with many loose ends (not literally, of course) to stimulate experimenting with RF circuitry at a small outlay. Looking at the circuit diagram you may recognize a modified version of the SW Converter for AM Radios described elsewhere in this issue. The modifications were necessary to make the circuit compatible with a digital rather than analogue AM car radio. The main difference between digital AM radios and their all-analogue predecessors is that tuning is in 9 kHz (some-times 4.5 kHz steps) in compliance with the international frequency allocation for the band. Obviously, that particular step size, desirable as it may be on MW, is a stumbling block if you want to use a digital AM receiver in combination with a frequency step-up converter for SW, where chaos reigns and there is no fixed step size. The first attempt was to make the crystal oscillator variable by about 5 kHz each way.   SW Co...

PWM Based Speed Control for DC Motors

Image
There are several methods for controlling the speed of DC motors. One simple method is to add series resistance using a rheostat. As considerable power is consumed in the rheostat, this method is not economical. Another method is to use a series switch that can be closed/opened rapidly. This type of control is termed as chopper control. We’ve described here a PWM-based chopper circuit that smoothly controls the speed of general-purpose DC motors. Fig.1: Block diagram of PWM-based speed controller Fig. 1 shows the block diagram of a basic PWM-based chopper. The circuit shown in Fig. 2 is designed as per this diagram. A dual timer IC (NE556) is used to configure both the astable as well as the monostable multivibrator. Timing components for the astable are chosen to provide a frequency of 546 Hz, while the monostable components are selected to obtain a maximum pulsewidth of 2.42 ms. Diode D1 improves duty factor of the astable oscillator output, whereas D2 acts as a free-wheeling diode. ...

Noise Suppression For R C Receivers

Image
Receiver interference is hardly an unknown problem among model builders. Preventive measures in the form of ferrite beads fitted to servo cables are often seen in relatively large models and/or electrically driven models, to prevent the cables from acting as antennas and radiating interference to the receiver. If miniature ferrite beads are used for this purpose, the connector must be first be taken apart, after which the lead must be threaded through the bead (perhaps making several turns around the core) and then soldered back onto the connector. Project Image : Noise Suppression For R/C Receivers Image An interference source can also cause problems in the receiver via the power supply connection.The battery is normally connected directly to the receiver, with the servos in turn being powered from the receiver.  The servos can draw high currents when they operate, which means they can create a lot of noise on the supply line. This sort of interference can be kept under control b...

Simple Automatic Switch For Audio Power Amplifier

Image
Circuit of an automatic switch for audio power amplifier stage is presented here. The circuit uses stereo preamplifier output to detect the presence of audio to switch the audio power amplifier on only when audio is present. The circuit thus helps curtail power wastage. IC1 is used as an inverting adder. The input signals from left and right channels are combined to form a common signal for IC2, which is used as an open loop comparator. IC3 (NE556) is a dual timer. Its second section, i.e., IC3(b), is configured as monostable multivibrator. Output of IC3(b) is used to switch the power amplifier on or off through a Darlington pair formed by transistors T1 and T2. IC3(a) is used to trigger the monostable multivibrator whenever an input signal is sensed. Circuit diagram: Automatic Switch For Audio Power Amplifier Circuit Diagram Under ‘no signal’ condition, pin 3 of IC2 is negative with respect to its pin 2. Hence the output of IC2 is low and as a result output of IC3(a) is high....

Step Up Converter For 20 LEDs

Image
The circuit described here is a step-up converter to drive 20 LEDs, designed to be used as a home-made ceiling night light for a child’s bedroom. This kind of night light generally consists of a chain of Christmas tree lights with 20 bulbs each consuming 1 W, for a total power of 20 W. Here, in the interests of saving power and extending operating life, we update the idea with this simple circuit using LEDs.  Power can be obtained from an unregulated 12 V mains adaptor, as long as it can deliver at least about 330 mA.  The circuit uses a low-cost current-mode controller type UCC3800N, reconfigured into voltage mode to create a step-up converter with simple compensation. By changing the external components the circuit can easily be modified for other applications. To use a current-mode controller as a voltage-mode controller it is necessary to couple a sawtooth ramp (rising from 0 V to 0.9 V) to the CS (current sense) pin, since this pin is also an input to the internal PWM com...

LED Flasher for Cars and Motorcycles Circuit Diagram

Image
This is a flasher that uses 4 high brightness LEDs that can be used in Automotive , Motorcycle or bicycle . It uses the IC 555 which is a monostable to adjust the flasher you can use the RV1 , which can be a potentiometer or trim pot 100k . If built in SMD it fits within the own flashlight .  LED Flasher for Cars and Motorcycles Circuit Diagram

Photo Tuning for the iPhone an overview of removable lenses and lens

Image
iPhone has long evolved from multifunctional gadget smartphone with great potential. Engineers and designers are creating more and more new devices for its transformation. With special docking stations, iPhone can be turned into a retro-radio from the 70s or a full-fledged gaming console. He may even become a thermometer. Yet the most common feature is, of course, after calling themselves remains photograph. iPhone is easy to replace a simple digital cameras. Expanding the field of creativity, using removable lenses, and other devices. High-quality images with the iPhone - easily If the quality of the pictures for you coming to the fore and you want to make great pictures, then do without the removable lenses, you will be impossible. Fortunately for the iPhone developed them quite a lot. We represent several options. 8x zoom closer to the action there is no difficulty. The images are crisp, clear. The kit included a mini-tripod for more convenient use of your iPhone. It includes lens F...