Showing posts with label a. Show all posts
Showing posts with label a. Show all posts

Tuesday, February 4, 2014

Build a Tremolo Effect Circuit Diagram

This tremolo effect circuit uses the XR2206 and the TCA730 IC which is designed as an electronic balance and volume regulator with frequency correction. The circuit is use full for stereo channels and it also has the ability to simulate the Lesley effect aka rotating loudspeaker effect.

How does the tremolo effect circuit works
Balance and volume settings are done with a linear potentiometer for both channels. If this potentiometer is replaced with an AC voltage source, a periodic modulation of the input signal can be achieved. This AC voltage source comes from the function generator IC XR2206. This IC generates square, triangle and sine wave signals but for this project we use only the sine wave.

IC  Tremolo Effect Circuit Diagram

 Tremolo Effect Circuit Diagram

The modulation voltage can be varied with P1 from 1 Hz up to 25 Hz. Resistor R3 sets the operation level of the sine wave generator. R5 and R6 set the DC voltage and the sine wave amplitude at the output. C2 is a ripple filter. The square wave output of the XR2206 drives T2 and a LED to optically display the frequency.

The modulating voltage reaches pin 13 of TCA730 via P3 and R10. This input functions as the volume control or in this case the volume modulation. The degree of the balance modulation (Lesley effect) can be varied with P2. A regulated power supply using 7815 IC is recommended. Do not use a non-stabilized power supply since the current variations would influence the modulation negatively.
Attach the 7815 IC to a good heat sink (about 10 cm2).
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Thursday, January 9, 2014

Here will introduce a palm size cell phone jammers

The manufacture process and technology of cell phone jammers will be renewed and revised.
To pay a certain amount of calls per month, pay the full two years can have this phone and given 14 days probation period, if you are not satisfied, you can cancel the agreement, returned to the mobile phone network operators. This is our country, "China Mobile and China Unicom launched prepaid calls to send the phone is somewhat similar, the difference is more humane, the foreign service, you can have the 14-day trial period, if you use unhappy, and free exchange within 14 days of the other models, this machine without the network or not, you have the final say. All there is this machine 14 days. The machine fineness of good items fineness of 99 to 100%, all original accessories. The working instruction of cell phone jammers should be renewed too.
14 secret in a foreign country, tried, strictly speaking, not a new machine, it should be said to be filling the new machine; appearance is difficult to identify due to foreign network operators require the phone to fourteen days trial period can not be damaged, it will be net of depreciation expense, so a lot of fourteen days the machine appearance is unable to identify whether the new machine; concrete from several aspects: 1, the packaging is worn; a close look at the phone The charging port and battery with or without scratches headphones and related accessories to be opened too; 3, enter the mobile phone interface to see whether the call records and contacts with or without record. It is the three-antenna wireless signal cell phone jammers .Here will introduce a palm size cell phone jammers
Purchase Note: the 14 secret 14 secret and a new machine purchase price difference of $ 100-200, do not rule out some distribution will take the 14 secret when a new machine for sale, at the time of purchase must be carefully view; not all phones 14 secret, and generally there are 14 secret specific models are as follows: Nokia N-GAGE, Dopod 686, the XDA, the SIEMENS SX65, Dopod 515 (SPV) Sony Ericsson T610, Panasonic GD87, NEC, C616, C313, Motorola A835, a920 models . Trigger is also the last one to two years to appear. The so-called trigger is assembled machine. Outflow from the mobile phone production factory accessories by skilled workers, self-assembly sales. Here will introduce a new type of three antenna wireless signal cell phone jammers .
For example, the past two years the fire of the Sony Ericsson T618, factories located in Beijing, workers tried a variety of ways to take the accessories directly from the pipeline, and then brought back home, assembled, sold to wholesalers. This phone a lot of accessories do not go through quality inspection, so the quality is uneven, and definitely do not recommend the purchase. On one of the phones the difference between parallel and mainstream. First affirmed either parallel or licensed, are regular manufacturers. Parallel does not mean that products mixed with water made a false parallel as counterfeit, counterfeiting, the degree of integration of mobile phone technology is not yet behind to make people imitation, unless it is a OEM product, for example, Kejian and Samsung. Lenovo and LG, Capitel, and Nokia, and so on.  cell phone jammers is recently well received by the customer in the domestic market and oversea market.
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Friday, December 27, 2013

Build a PIC Security System Dials Your Cell Phone Circuit Diagram

This is a simple PIC Security System Dials Your Cell Phone Circuit Diagram. Do-it-yourself phone dialer security system calls your cell phone, office etc. whenever a door or window is opened, or panic button is pressed. Great Home Alarm.

PIC Security System Dials Your Cell Phone Circuit Diagram

PIC Security System Dials Your Cell Phone Circuit Diagram


The circuit consists of a small PIC microcontroller, assembly program, and a few other parts to detect a switch closure from an open door, window, or manual push button and then dial the cell phone number, and transmit a steady tone to indicate the source of the call. The circuit uses the pulse dialing system to interrupt the line connection a number of times to indicate each digit. Pulse dialing (the oldest form of dialing) works by actually disconnecting or "hanging up" the phone line a number of times to indicate each digit. For example, the digit "5" would be dialed by disconnecting and reconnecting the line 5 times in short intervals of about 100mS. There is about a 1 second pause (with the line connected) between each digit. The timing is not critical and I was able to dial 411 and connect to the local information service just using a momentary push button switch in series with the phone line.

Circuit Operation:
In operation, the switch closure is detected on pin 7 of the processor which activates the reed relay and takes the line off-hook for 3 seconds to establish the dial tone. The processor then dials the number by opening and closing the relay a number of times for each digit. When dialing is complete, the processor waits 3 seconds and then transmits a steady tone of about 300Hz for 30 seconds through the modem transformer. The call is then terminated and the processor waits for the switch to open before resetting.

Design Considerations:

The PIC16F628 (18 pin) processor was selected because I had a few on hand and my homemade hardware programmer only accepts 18 pin devices. A smaller 8 pin device could have been used since only three I/O lines are needed, but the difference in cost is only about $1.50. One of the I/O lines (RA5) is used for programming and is always an input, but can used as a functional input so the switch closure could be detected on this line thus eliminating the need for one pullup resistor. But I elected to use 3 consecutive I/O pins (7,8,9) of the 8 bit port B and leave RA5 pulled up with a extra 10K resistor.

The output pins (8,9) that drive the relay and transformer are limited to 25mA of current each, so an extra transistor (2N2222A) was needed to supply additional current to the relay coil. The transformer resistance is around 100 ohms, so an additional 330 ohm resistor was added in series with pin 9 to limit the transformer current to around 10mA. An LED indicator and 330 ohm resistor were used on pin 8 to observe the dialing activity and indicate the line status. Several of the parts (relay, transformer and blocking capacitor) were obtained from an old 56K modem card.

The schematic shows a 47uF / 50 volt non-polarized capacitor used to block DC current to the transformer, however a regular polarized 50uF cap could be used if correct phone line polarity is observed. The modem was probably designed to work with unknown polarities at different locations, so a non-polarized cap was used. Its possible the cap and 470 ohm resistor can be replaced with a single resistor in series with the line to set the "off hook" line current to around 20mA. This may cause partial saturation of the transformer and reduced audio level, but might work well enough.

The power supply voltage is not critical and a 4.5 volt supply from three AA batteries should work. Or a switching type regulated 5 volt wall transformer can be used. The problem is insuring the relay gets enough voltage to operate. The rest of the circuit should run on reduced voltage. I used a 4.2 volt cell phone charger that worked well.

 Softwre
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Thursday, December 26, 2013

Build a Simple Emergency Light and Alarm Circuit Diagram

This Simple Emergency Light and Alarm Circuit Diagram is permanently plugged into a mains socket andNI-CD batteries are trickle-charged. When a power outage occurs,the lamp automatically illuminates. Instead of illuminating alamp, an alarm sounder can be chosen.When power supply is restored, the lamp or the alarm isswitched-off. A switch provides a “latch-up” function, in orderto extend lamp or alarm operation even when power is restored.Circuit operation:Mains voltage is reduced to about 12V DC at C2`s terminals, bymeans of the reactance of C1 and the diode bridge (D1-D4). Thusavoids the use of a mains transformer.

 Simple Emergency Light and Alarm Circuit Diagram

Simple Emergency Light and Alarm Circuit Diagram


Trickle-charging current for the battery B1 is provided by theseries resistor R3, D5 and the green LED D6 that also monitorsthe presence of mains supply and correct battery charging.Q2 & Q3 form a self-latching pair that start operatingwhen a power outage occurs. In this case, Q1 biasing becomespositive, so this transistor turns on the self latching pair.

If SW3 is set as shown in the circuit diagram, the lampilluminates via SW2, which is normally closed; if set the otherway, a square wave audio frequency generator formed by Q4, Q5 andrelated components is activated, driving the loudspeaker.If SW1 is left open, when mains supply is restored the lamp orthe alarm continue to operate. They can be disabled by openingthe main on-off switch SW2.If SW1 is closed, restoration of the mains supply terminateslamp or alarm operation, by applying a positive bias to the Baseof Q2.

Notes:

Close SW2 after the circuit is plugged.Warning! The circuit is connected to 220Vac mains, then some parts in the circuit board are subjected to lethal potential! avoid touching the circuit when plugged and enclose it in a plastic box. 

Parts List
R1____________220K 1/4W Resistor
R2____________470R 1/2W Resistor
R3____________390R 1/4W Resistor
R4______________1K5 1/4W Resistor
R5______________1R 1/4W Resistor
R6_____________10K 1/4W Resistor
R7____________330K 1/4W Resistor
R8____________470R 1/4W Resistor
R9____________100R 1/4W Resistor

C1____________330nF 400V Polyester Capacitor
C2_____________10΅F 63V Electrolytic Capacitor
C3____________100nF 63V Polyester Capacitor
C4_____________10nF 63V Polyester Capacitor

D1-D5________1N4007 1000V 1A Diodes
D6______________LED Green (any shape)
D7___________1N4148 75V 150mA Diode

Q1,Q3,Q4______BC547 45V 100mA NPN Transistors
Q2,Q5_________BC327 45V 800mA PNP Transistors

SW1,SW2________SPST Switches
SW3____________SPDT Switch

LP1____________2.2V or 2.5V 250-300mA Torch Lamp

SPKR___________8 Ohm Loudspeaker

B1_____________2.5V Battery (tw1o AA NI-CD rechargeable cells wired in series)

PL1____________Male Mains plug

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Friday, December 20, 2013

Build a Photomultiplier Circuit Diagram

How to Build a Photomultiplier Circuit Diagram? This Photomultiplier Circuit Diagram is typical of the way that a photomultiplier tube is used. The circuit shown is ac coupled, but if dc coupling is needed, the capacitor can be omitted and a suitable interfacing method used. A typical tube is the widely available 931/931A.

Photomultiplier Circuit Diagram

Photomultiplier Circuit Diagram

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Thursday, December 19, 2013

Build a Full Wave Rectifier Circuit Diagram

This is the simple full wave rectifier circuit diagram.When equality of two equations shown in satisfied, full-wave output of circuit is symmetrical. The circuit uses a CA3140 BiMOS op amp in an inverting gain configuration.

Full Wave Rectifier Circuit Diagram

Full Wave Rectifier Circuit Diagram

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Wednesday, December 18, 2013

Build a Digital Theremin Circuit Diagram

Theremin circuit shown in this schematic diagram uses digital component, so we can call it a digital Theremin. This circuit employs  logic inverter 74C04 or CD4069 hex inverter and CD4046 phase-locked-loop (PLL) IC. 

The CD4069 logic inverter is operated as a fixed-frequency oscillator with  frequency around 100kHz. The CD4046 is operated as a variable frequency oscillator which is adjustable around 100kHz. The exact center frequency of the on-chip oscillator is determined by R4, C2 and R3. Here is the schematic diagram of the circuit. 

Digital Theremin Circuit Diagram

The frequency of variable oscillator frequency circuit can be shifted several kilohertz by moving your hand approaching the antenna since the C2 and the antenna form an equivalent parallel capacitance. The frequency of the variable oscillator should be set to the same frequency of fixed oscillator when there is no hand or human body close to the antenna. 

This  calibration is done by adjusting the  zero control R4 pot with this simple rule: If  both oscillators (the fixed and the variable) are set to the same frequency then the Theremin will produce no output (silent). This Theremin circuit will start  producing audible tone if you move your hand approaching the antenna since it will shift the frequency of the variable oscillator. You can play this Theremin circuit by moving your right hand around the antenna and at the same time turning the volume knob R5 with your left hand.
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Tuesday, December 17, 2013

How to Build a Simple Power supply Circuit Diagram

To day i share this post how to Build a simple power-supply circuit diagram lets start . This simple power supply circuit diagram delivers plus and minus 9 V to replace two 9-V batteries. The rectifier circuit is actually two separate full-wave rectifiers fed from the secondary of the transformer. One full-wave rectifier is composed of diodes D1 and D2, which develop +9 V, and the other is composed of D3 and D4, which develop -9 V. 

Each .diode from every pair rectifies 6.3 Vac, half the secondary voltage, and charges the associated filter capacitor to the peak value of the ac waveform, 6.3 x 1.414 ~ 8.9 V. Each diode should have a PIV, Peak Inverse `Voltage, rating that is at least twice the peak voltage from the transformer, 2 x 8.9 ~ 18 V. The 1N4001 has a PIV of 50 V. I hope you are enjoy this circuit.

Simple Power supply Circuit Diagram

Simple Power supply Circuit Diagram


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Monday, December 16, 2013

Building A Park Aid

This circuit was designed as an aid in parking the car near the garage wall when backing up. LED D7 illuminates when bumper-wall distance is about 20 cm., D7+D6 illuminate at about 10 cm. and D7+D6+D5 at about 6 cm. In this manner you are alerted when approaching too close to the wall. All distances mentioned before can vary, depending on infra-red transmitting and receiving LEDs used and are mostly affected by the color of the reflecting surface. Black surfaces lower greatly the devices sensitivity.

Building A Park Aid Ciruit
Park Aid Circuit Diagram

Obviously, you can use this circuit in other applications like liquids level detection, proximity devices etc. IC1 forms an oscillator driving the infra-red LED by means of 0.8mSec. pulses at 120Hz frequency and about 300mA peak current. D1 & D2 are placed facing the car on the same line, a couple of centimeters apart, on a short breadboard strip fastened to the wall. D2 picks-up the infra-red beam generated by D1 and reflected by the surface placed in front of it.

The signal is amplified by IC2A and peak detected by D4 & C4. Diode D3, with R5 & R6, compensate for the forward diode drop of D4. A DC voltage proportional to the distance of the reflecting object and D1 & D2 feeds the inverting inputs of three voltage comparators. These comparators switch on and off the LEDs, referring to voltages at their non-inverting inputs set by the voltage divider resistor chain R7-R10.

Notes:


  1. Power supply must be regulated (hence the use of IC3) for precise reference voltages. The circuit can be fed by a commercial wall plug-in power supply, having a DC output voltage in the range 12-24V.
  2. Current drawing: LEDs off 40mA; all LEDs on 60mA @ 12V DC supply.
  3. The infra-red Photo Diode D2, should be of the type incorporating an optical sunlight filter: these components appear in black plastic cases. Some of them resemble TO92 transistors: in this case, please note that the sensitive surface is the curved, not the flat one.
  4. Avoid sun or artificial light hitting directly D1 & D2.
  5. If your car has black bumpers, you can line-up the infra-red diodes with the (mostly white) license or number plate.
  6. Its wiser to place all the circuitry near the infra-red LEDs in a small box. The 3 signaling LEDs can be placed far from the main box at an height making them well visible by the car driver.
  7. The best setup is obtained bringing D2 nearer to D1 (without a reflecting object) until D5 illuminates; then moving it a bit until D5 is clearly off. Usually D1-D2 optimum distance lies in the range 1.5-3 cm.
  8. If you are needing a simpler circuit of this kind driving a LED or a relay, click Infra-red Level Detector
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Monday, August 12, 2013

How to Build a 2 to 4 Wire Audio Converter

This audio converter circuit maintains 40 dB of isolation between the two halves of entry and exit of a four-line son, while allowing a line connecting two son. A balancing potentiometer, R, adjusts the gain of zero lC2to crossing the inlet to the outlet .

The adjustment is done in terms of work just after installation by inserting a 1 kHz tone at the entrance of four son and setting R to the minimum output signal 82-ohm dummy-load resistor is placed between two wire terminals .

 2 to 4 Wire Audio Converter Circuit Diagram

How to Build a 2 to 4 Wire Audio Converter

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Saturday, August 10, 2013

How to Manufacture Automobile Electronic Parts and Earn a Handsome Income


To set up an auto electrical manufacturing unit, its important to have a thorough knowledge regarding the various technicalities associated with the field. The article makes a comprehensive approach and explains all the issues related to the subject. We begin with the basic raw materials and man power required for the intended installations and further proceed with the list of electronic parts that can be manufactured and sold in the relevant markets. The products that are included for the production are flasher buzzers, piezo buzzers, CDI units, musical horns, auto testing machine etc. How these can be made is also explained through discrete articles, linked in the sections.


Among most electronic products, the ones which are associated with automobiles are probably the largest selling types and are always in demand. Manufacturing these items and selling is surely a lucrative business. Here we discuss the procedures in details.

Today one thing that’s common with all of us is that we all want to earn money. However, with the population that’s ever growing, all sources of earning money have been captured, resulting in a cut-throat competition in every field. It’s feasible to make a way out from this intense competition only if you can manage an area where you are the master, and are able to create a monopoly.
The auto market today has become huge and with tremendous opportunities, but also it’s flooded with some tough competitors. Since vehicles cannot work without electricity and other associated electronic accessories, the products related to these have cropped up extensively and you can find a whole range of all sorts of electronic products, some of which are mandatorily used while some are just for decoration purposes. Whatever may be the seriousness of the application, electronic products have become today an integral part with all types of vehicles.
Thus, auto electronics is probably one such field where you can expect some good money, provided you are equipped with all the know-how required for the initial manufacturing set ups.
In this article we are going to discus the technical aspects required for setting up an auto electronic manufacturing plant for TWO-WHEELERS and THREE-WHEELERS, small though. However here we won’t discuss the legal procedures involved, like acquiring VAT number, CST number etc.
The following steps provide some crucial data regarding earning money by manufacturing auto electrical products:


What Electronic Products can be Manufactured for the Two-Wheeler Auto Market?

There are probably a host of them which you can choose from, or rather go for the entire range. Supplying or keeping the whole range will provide you with a better chance of fairing among the many vying vendors.
The items commonly associated with two/three wheelers are the side indicators, CDI units, rectifiers, buzzers, melody maker horn, etc.
To begin a manufacturing plant for producing the above auto electrical items, you would first want to acquire a space with a descent area; preferably a 20 by 40 sq ft will be ideal and sufficient to begin with.
You would also require fixing some furniture in the form of a long narrow table closely attached to the longer wall and a few number of chairs that can be accommodated. This set up is required for implementing the production process by lining up the workers so that the assemblies can be done in the most efficient manner.
The workers who would be responsible for assembling the electronic parts will need important and useful tools like the soldering iron, wire nipper, wire stripper, soldering paste, thinner etc. so all these must be procured in required numbers.
The engineers may require more sophisticated tools like multitester, desolder pump/wik, magnifying glass, power supply etc. along with the above mentioned tools. Procure all of these as per the requirements.
We are assuming that the workers required for carrying out the procedures would be appropriately employed, so we are not discussing how they can be contacted and interviewed etc.
After the initial set ups as discussed above are done, it’s time to select the items and chalk out the procedures plans. It would include the following points:
There should be at least one product that has the potentials to run through out the year, under all odds. Make it the base of your company’s production line.
  As an example you may select the buzzer unit, as it’s the easiest to assemble, finish, and sell, moreover the concerned raw materials are easily available. However this product may carry pretty low profit margins and you would need to sell tons of them to actually witness any significant income, but can be rest assured a steady flow of income through out the season.
The circuit of an electronic buzzer is discussed  HERE, it’s the simplest in design and widely used all across the world for automobile applications, especially in conjunction with side turn signal or flasher units.
The next type of selected product would be the one which sells like “hot cake” in the market, has reasonably less competition and has the potentials of providing fairly high profit margins.
You can assess the product and insist the engineers to do improvements in the form of cost cutting or adding new features into the product, so that it can stand out from the rest of the brands. This will give you an edge while introducing your product in the market.
A flasher with buzzer is one such item which satisfies the above conditions, I have already published an improved and low cost flasher buzzer circuit in Bright Hub – You can check it out  HERE.
  CDI units are another indispensable auto part which can be manufactured and sold with good profit margins. You can find it in Bright Hub, just type the relevant words in the given in-site Google search box.


You can refer this article to know how to make a two-three wheeler CDI circuit.
Having discussed the manufacturing process, testing these circuits for accuracy and reliability can become a crucial issue. A suitable auto part testing machine therefore becomes imperative, without which the whole set up may fail or jeopardize.
If you inquire about such a universal auto part testing machine, you would probably get it at very high costs. In Pune (India), Teckson Electronics has the monopoly of manufacturing these machines, and they charge an awful Rs.12000/- for each of them.
I investigated the mechanism and developed my own version at less than Rs. 600/- which is more efficient, and more reliable than the above unit. The complete design will be comprehensively discussed in one of my forthcoming articles.
That’s all what may be basically required and concludes the fundamental technical procedures involved with setting up an electronic auto part manufacturing unit.





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Tuesday, August 6, 2013

Build a Positive And Negative Voltage Switching Supply

Build a Positive And Negative Voltage Switching Supply. An LT1172 generates positive and negative voltages from a 5-V input. The LT1172 is configured as a step-up converter. To generate the negative output, a charge pump is used. C2 is charged by the inductor when D2 is forward-biased and discharges into C4 when LT1172`s power switch pulls the positive side of C2 to ground. 

 Positive And Negative Voltage Switching Supply  Circuit Diagram

 Positive And Negative Voltage Switching Supply  Circuit Diagram
 
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Saturday, August 3, 2013

Build a 0 To 12V 1A Variable Power Supply Circuit Diagram

This 0- to 12-Vdc variable power supply uses an IC voltage regulator and a heavy-duty transformer to provide a reliable dc power supply. Looking at the schematic shown, you can sec that transformer Tl has a 120-V primary and a 28-V secondary. Filtered dc is fed to the input (pin 2) of the LM317T voltage regulator, IC, which keeps the voltage at its output constant (pin 3) regardless (within limitations) of the input voltage. 

Pin 1 of the LM317T is the adjustment pin. Varying the voltage on pin 1 (via PI) varies the output voltage. Diodes D5 through D7 and LEDs LI through L3 give an approximate indication of the output voltage. Each LED/diode path has a limiting resistor to limit the current to a level that is safe for the LED. 

 Build a 0 To 12V, 1A Variable Power Supply Circuit Diagram


Build a 0 To 12V, 1A Variable Power Supply Circuit Diagram
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Friday, August 2, 2013

A Good Auto Sound System is a Requirement not a Luxury

How do you decide which auto sound system is best for you? This is a question that many consumers ask in the U. S. each and every day. The truth is that only you can decide what kind of sound you find enjoyable and what you are seeking in the sound system you will ultimately purchase. A good sound system will greatly improve how you feel about not only the vehicle you drive but also your disposition after your daily commute. It may seem like such a small thing, the changing of a sound system, but it does seem to have such a profound impact on how we start our days. Of course we all know that getting your day off to a good start sets the tone for the entire day and if that day is Monday it sets the tone for not only the day ahead but also the week to come.


Music affects almost every aspect of our lives. Most of us do not realize the impact that music has on our day-to-day lives and it is quite difficult because our world seems to be filled with it. It is much easier however, to explain the difference a good sound system makes. Its funny, I find myself in a hurry to get out of stores that have lousy sound systems and speakers that dribble out little more than static while I can shop for hours in a store that has tasteful music playing in the background over a good sound system. I prefer the volume lower and the music playing in the background rather than being the center of my attention.

Most of us find that soft music playing in the background is rather unobtrusive and allows us to get along with our thoughts and the mission at hand while loud music blaring over antiquated speakers does a great deal to disrupt our thought processes which will only serve to send us along to the next errand on our list. If youll notice it seems that clerks in the stores where the loud music blares along are often not as even tempered as those in stores that play music at respectful volumes and have very well kept sound systems. I think I would be cranky too after listening to music in a manner that music wasnt meant to be heard.

Im not a music snob by any means; I simply enjoy listening to music for the sake of actually hearing the music. Loud music is good sometimes but not when I have other things on my mind. I prefer that music remain in the background when Im running about taking care of errands, even in the car. The hallmark of a good auto sound system is that it sounds good even at low volumes. This means you can enjoy music in the background, hum along, or simply ignore the music in favor of the action taking place on the road.

The point Im trying to make is that even though you may not realize the impact that a good auto sound system has on music immediately, you will definitely feel the difference it makes over time. The better the sound system, the better the sound and music is after all, sound.

If you are a true lover of music and spend a great deal of your week or even any given day in your vehicle, doesnt it make sense to invest heavily in your auto sound system? I know for me that particular decision is a no brainer. I love music and it is an important part of not only my life but also the lives of my children. As a result we spend a lot of time listening to the radio in our SUV and singing along. Even when we arent listening to music, I enjoy listening talk radio and the news on NPR. These things are an important part of my day and I really enjoy all that each and every one adds to my life. Because of that, I find my investment in a good auto sound system to be a requirement rather than a luxury.

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Tuesday, July 30, 2013

Build a Charger Extends Lead Acid Battery Life Circuit Diagram

The Charger Extends Lead-Acid Battery Life Circuit Diagram furnishes an initial charging voltage of 2.5 V per cell at 25°C to rapidly charge a battery. The charging current decreases as the battery charges, and when the current drops to 180 mA, the charging circuit reduces the output voltage to 2.35 V per cell, floating the battery in a fully charged state. 

This lower voltage prevents the battery from overcharging, which would shorten its life. The LM301A compares the voltage drop across R1 with an 18-mV reference set by R2. The comparator`s output controls the voltage regulator, forcing it to produce the lower float voltage when the battery-chaiging current passing through R1 drops below 180 mA. the 150-mV difference between the charge and float voltages is set by the ratio of R3 to R4. The LEDs show the state of the circuit . 

Charger Extends Lead-Acid Battery Life Circuit Diagram

Charger Extends Lead-Acid Battery Life Circuit Diagram

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Friday, July 5, 2013

Constructing a Universal Power Supply using LM317 Rise

This is a basic,  Universal Power Supply voltage regulator circuit using an LM317, 3-terminal regulator in a TO-220package. The Universal Power Supply output voltage can be set to anywhere in the range one.5V to 30V by selecting resistances. By using a potentiometer, R2, as of the resistors you can dial up the output voltage wanted. Either AC or DC input can be supplied to the PCB by a socket or terminal block. Connection can be either way around. This is because they have provided a bridge rectifier on board. The input DC voltage to the regulator must be at least two.5V above the necessary output voltage. An off/on switch is provided.

For lots of applications (say 12V at 60mA) a heat sink wont be required. The LM317 will provide slightly higher output voltages than 30 volts. However, for most hobbyists over 30V wont be needed. So to make a small PCB they have used some electrolytic capacitors rated to 35 volts. To be safe for continuous operation the maximum input DC voltage to the regulator ought to not be over 33V. With a two.5V to three.0V drop across the regulator this will give a regulated output of 30V. You can draw up to one.5A from the LM317. In case you need higher then use an LM338T rated to 5A.

When outside capacitors are used with any IC regulator it is lovely practice to add protection diodes to prevent the capacitors discharging back in to the regulator in the event of abnormal operating conditions, like a sudden short circuit on the input or the output, or a back emf from an inductive load. That is the function of D one and D Two.

The worth of R1 can range anywhere from 120R to 1200R However, circuits from most other sources settle on using either 220R or 250R. They have used 240R or 250R. The voltage drop across R1is one.25V for all values, and this is the key to the design. one.25V is the reference voltage of the regulator. Whatever current flows through R1 also flows through R2, and the sum of the voltage drops across R1 and R2 is the output voltage. (Additional current Id also flows in R2 but it is usually 50uA so is negligible.)

The design formula are:
VOUT = 1.25 (1 + R2/R1) volts, or alternatively
R2/R1 = (VOUT/1.25) - 1

So in case you know VOUT & R1 is 250R then you can calculate R2. In case you find that the 5K potentiometer used forR2 does not give you the degree of fine control over the voltage output range that you need then you can use these formula to fine-tune R1 & R2 to better suited values.


Universal Power Supply Schematic Diagram


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Wednesday, June 12, 2013

3 Wire Serial LCD Circuits using a Shift Register










74HC595 is a high-speed 8-bit serial in, serial or parallel-out shift register with a storage register and 3-state outputs.
The shift register and storage registers have separate clocks, SH_CP and ST_CP respectively. Data in the shift register is shifted on the positive-going transitions of SH_CP, and the content of shift register will be transferred to the storage register on a positive-going transition of the ST_CP. If we tie both the clocks together, the shift register will always be one clock ahead of the storage register. The 8-bit data of the storage register will appear at the parallel output (Q0-Q7) when the output enable (OE) is low.
In this project, SH_CP and ST_CP are tied together. So, if we want to receive a serially transferred 8-bit into parallel form at Q0-Q7, an extra clock pulse is required after transmitting the 8-th bit of serial data because the clocks are tied and the storage register is 1-clock behind the shift register. 

HD44780-based character LCD

 
 All HD44780 based character LCD displays are connected using 14 wires: 8 data lines (D0-D7), 3 control lines (RS, E, R/W), and three power lines (Vdd, Vss, Vee). Some LCDs may have LED backlight and so they may have additional connections (usually two: LED+ and LED-).

Providing detail explanation of individual LCD pin doesnt fall within the scope of this project. If you are a beginner with LCD, I recommend to read these two articles first from Everyday Practical Electronics magazine : How to use intelligent LCDs  

 The SH_CP (11) and ST_CP (12) clock inputs of 75HC595 are tied together, and will be driven by one microcontroller pin. Serial data from microcontroller is fed to the shift register through DS (14) pin. OE (13) pin is grounded and reset pin MR (10) is pulled high. Parallel outputs Q0-Q3 from 74HC595 are connected to D4-D7 pins of the LCD module. Similarly, Q4 output serves for RS control pin. If the LCD module comes with a built-in backlight LED, it can simply be turned ON or OFF through LED control pin shown above. Pulling the LED pin to logic high will turn the back light ON.

 Software 
A first, a bit of data fed to DS pin of 74HC595 appears at Q0 output after 2 clocks (because SH_CP and ST_CP are tied). So, sending 4-bit data (D4-D7) and an RS signal require 6 clock pulses till they appear at Q0-Q4 outputs respectively. When the LCD module is turned ON, it is initialized in 8-bit mode. A number of initializing commands should be sent to operate the LCD module in 4-bit mode. All the driver routines that are discussed here are written in mikroC compiler. They work only for a 16x2 LCD module. User can modify the initialization operations inside the Initialize_LCD() routine to account for other LCD configurations. The driver routines and their functions are described below. 
- Initialize_LCD() : It initializes the LCD module to operate into 4-bit mode, 2 lines display, 5x7 size character, display ON, and no cursor.
- Write_LCD_Data() : Sends a character byte to display at current cursor position. 
- Write_LCD_Cmd() : Write a command byte to the LCD module. 
- Write_LCD_Nibble() : Data or command byte is sent to the LCD module as two nibbles. So this function routine takes care for sending the nibble data to the LCD module.
- Write_LCD_Text() : This routine is for sending a character string to display at current cursor position.
- Position_LCD() : To change the current cursor position
At the beginning of your program, you need to define Data_Pin, Clk_Pin, and Enable_Pin to the chosen microcontroller ports. I am going to demonstrate here how to use these driver routines to display two blinking character strings, Message1 and Message2, at different locations. I am going to test our serial LCD module with PIC12F683 microcontroller. The test circuit is shown below.
Note: My PIC12F683 Settings
Running at 4 MHz internal clock, MCLR disabled, WDT OFF.
Clock, Data, and Enable lines are served through GP1, GP5, and GP2 ports.


/* 3-wire Serial LCD using 74HC595
Rajendra Bhatt, Sep 6, 2010
*/
 
sbit Data_Pin at GP5_bit;
sbit Clk_Pin at GP1_bit;
sbit Enable_Pin at GP2_bit;
 
// Always mention this definition statement
unsigned short Low_Nibble, High_Nibble, p, q,  Mask, N,t, RS, Flag, temp;
 
void Delay_50ms(){
 Delay_ms(50);
}
 
void Write_LCD_Nibble(unsigned short N){
 Enable_Pin = 0;
 // ****** Write RS *********
 Clk_Pin = 0;
 Data_Pin = RS;
 Clk_Pin = 1;
 Clk_Pin = 0;
 // ****** End RS Write
 
 // Shift in 4 bits
 Mask = 8;
  for (t=0; t<4; t++){
   Flag = N & Mask;
   if(Flag==0) Data_Pin = 0;
   else Data_Pin = 1;
   Clk_Pin = 1;
   Clk_Pin = 0;
   Mask = Mask >> 1;
  }
  // One more clock because SC and ST clks are tied
  Clk_Pin = 1;
  Clk_Pin = 0;
  Data_Pin = 0;
  Enable_Pin = 1;
  Enable_Pin = 0;
}
// ******* Write Nibble Ends
 
 void Write_LCD_Data(unsigned short D){
 RS = 1; // It is Data, not command
 Low_Nibble = D & 15;
 High_Nibble = D/16;
 Write_LCD_Nibble(High_Nibble);
 Write_LCD_Nibble(Low_Nibble);
 }
 
void Write_LCD_Cmd(unsigned short C){
 RS = 0; // It is command, not data
 Low_Nibble = C & 15;
 High_Nibble = C/16;
 Write_LCD_Nibble(High_Nibble);
 Write_LCD_Nibble(Low_Nibble);
}
 
void Initialize_LCD(){
 Delay_50ms();
 Write_LCD_Cmd(0x20); // Wake-Up Sequence
 Delay_50ms();
 Write_LCD_Cmd(0x20);
 Delay_50ms();
 Write_LCD_Cmd(0x20);
 Delay_50ms();
 Write_LCD_Cmd(0x28); // 4-bits, 2 lines, 5x7 font
 Delay_50ms();
 Write_LCD_Cmd(0x0C); // Display ON, No cursors
 Delay_50ms();
 Write_LCD_Cmd(0x06); // Entry mode- Auto-increment, No Display shifting
 Delay_50ms();
 Write_LCD_Cmd(0x01);
 Delay_50ms();
}
 
void Position_LCD(unsigned short x, unsigned short y){
 temp = 127 + y;
 if (x == 2) temp = temp + 64;
 Write_LCD_Cmd(temp);
}
 
void Write_LCD_Text(char *StrData){
 q = strlen(StrData);
 for (p = 0; p
  temp = StrData[p];
  Write_LCD_Data(temp);
 }
 
}
 
char Message1[] = "3-Wire LCD";
char Message2[] = "using 74HC595";
 
void main() {
CMCON0 = 7;  // Disable Comparators
TRISIO = 0b00001000;  // All Outputs except GP3
ANSEL = 0x00; // No analog i/p
 
Initialize_LCD();
 
do {
 Position_LCD(1,4);
 Write_LCD_Text(Message1);
 Position_LCD(2,2);
 Write_LCD_Text(Message2);
 Delay_ms(1500);
 Write_LCD_Cmd(0x01);  // Clear LCD
 delay_ms(1000);
} while(1);
 
}
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Sunday, April 7, 2013

Digital Thermometer with data processing of a microcontroller AT89C4051

digital thermometer
Digital Thermometer 0-100.0°C is a digital thermometer that operates in modetemperature measurement in Celsius (° C). Digital Thermometer 0-100.0 ° C in this article uses data processor in the form of a microcontroller AT89C4051.



Temperature sensors used in Digital Thermometer 0-100.0 ° C. This temperature sensor LM35D. Digital Thermometer 0-100.0 ° C. It uses the temperature measurement data viewer in the form of 1 line LCD viewer. Digital Thermometer 0-100.0 ° C. It can display the temperature measurement data with a resolution of 0.1 ° C.

Digital Thermometer with data processing
Digital Thermometer Circuit Diagram


Digital Thermometer 0-100.0 ° C. These temperature sensors make use of LM35D as temperature sensing. In Digital Thermometer 0-100.0 ° C. This temperature sensor measurement data this LM35D (Level Voltage) is then converted into 4-bit binary data using the ADC CA3162.

Then the 4-bit data from ADC CA3162 which is a measurement of data if the temperature is in the AT89C4951 microcontroller so that it becomes an operating principle of temperature measurement based on digital thermometers. In the final stage of the Digital Thermometer 0-100.0 ° C. This is the appearance of digital data temperature measurement, using digital data viewer of the LCD 1 line.
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Friday, April 5, 2013

The Importance of a Good Auto Sound System

If you spend a good deal of time in you car, and yes, the morning commute to work and the evening commute home each and every day definitely counts, you are probably more than slightly aware of the benefits of having a good auto sound system. Your sound system is your companion in your travels most of the time. Even those who have children often spend a great deal of time driving alone.


The Importance of a Good Auto Sound SystemFor those long and sometimes lonely miles your auto sound system is the voice of reason, the energetic beat, and the information that keeps you up on current events, weather forecasts, and what is going on in the world of the rich and famous. Even if you arent all that into music there is the wide and wonderful world of talk radio that keeps many of us informed and inflamed about issues that are important to us and causes which we feel passionately about.

The proper auto sound system affects the way we hear everything that comes through our radios. It doesnt really matter if you have the latest and greatest of subscription programs, XML programming, or even digital radio if your sound system is poor the quality of your programming will never reach your ears. Your sound system is the difference in standard sounds coming through your speakers and excellence making its way to your ears.

Contrary to popular belief however, you do not have to have the loudest sound system in order to have the best sound system. The truth of the matter is that once the music is so loud it ceases to sound like music and comes across to those inside and outside of your automobile more as noise than the wonderful music it may be in other circumstances. While there are many who enjoy the throbbing and jumping sounds that come from over emphasized bass, there is something to be said for an auto sound system that is well rounded and balanced. A good sound system will make all aspects of the music sound better and not just a certain few.

The important thing about sound systems arent the price that they command, the bass that they flaunt, or even the most minute details of the making and manufacturing of the sound system. The true beauty of a sound system lies in the fact that it should be music to your ears. You and you alone can choose the sound system that you like best as every person has different things they will listen for and enjoy in not only their music but also their sound systems. I love many different types of music and as a result will tend to listen to several different music genres as well as a stint of talk radio on several different systems and elect the one that sounds the best on the most of the music platforms and genres I prefer. I recommend a course of action similar to this to all who are interested in purchasing an auto sound system for their vehicle.

One thing that often gets overlooked is how much time we really spend in our vehicles in the course of a week. Most people pay very little time, money, or attention the particular stereos we put into our vehicles when in reality we spend nearly as much time each week listening to our auto sound systems as we do watching the televisions in our home. Music is all around us and it deeply affects and enhances our joys, our sorrows, even our romance. For those reasons, shouldnt we invest as much, if not more, time and energy in a great auto sound system as we do in a television for our homes?

By taking the time to get the perfect sound system for our vehicles when we first purchase our automobiles we will enjoy the maximum benefit our sound systems can provide. By enjoying our sound system, more people are willing to hang on to their vehicles longer which actually saves a great deal of money in the long run while also increasing your overall enjoyment of your time spent commuting to and from work each and every day.

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Tuesday, April 2, 2013

Make A Virtual Phone Battery

Virtual cell phone battery is a replacement cell phone batteries for those of you who use the phone as a modem. Including myself, who use the phone as a modem HAIER d1200p internet.  Why must use this virtual battery. For those who surf hobby "full time" with a phone modem, would know the problem, the battery gets hot and fast reply wasteful even worn out.
virtual phone battery circuit
This tool is a good solution to keep and care for our cell phones from the possibility of damage from over-charging its battery.I created a virtual battery works as follows:We take the source of its power supply from the USB port because the port is very easy and simple to use and simply provide a standard current source when the phone is online (500-750mA).

The workings of the circuit is as follows:Diodes or diode 2Amper in 5239 this standard to provide a useful addition to the polarity of the voltage which is also a component of protection against misuse. You can just use a 1 Amp diode (IN4002-4007). I use the IN 5239 is due to be durable, more resistant to heat.4v3 zener diode IN4007 and configured to create a portal voltage of 5V (4.3 + 0.7 volt zener Vin4007) and is useful as a protection system against possible voltage spikes in the event of damage to the CPU.220nF capacitor as a stabilizer and a substitute for the original battery cells.

The following also 100pF capacitor to smooth and filter the dc current through the diode 5239 which came out of the induction logging.Configuration between zener4v3, IN4007 diode and C 220n form a cell replacement from the actual battery cells, because the battery was actually a capacitor which had a large capacity.You can just remove the three components mentioned above. although it can work fine .

But results are not as good as that use virtual cell (replacement), which certainly was the security which we have to think to avoid the things which are not in want.Making way is to use an old cell phone batteries which have been wasting his cell, a raft of this circuit and the solder terminals on the batteries with the polarity distinguished. Make two holes for the cable to the jack / USB jack.

 Determine the length of cable required to taste and use stranded cable with a diameter of at least 1mm.If some type of cell phone batteries are very thin, use a small box for this circuit and connect the two wires to the output voltage again for hp battery casing. Or also if you do not have a former battery casing, use alligator clips to the battery terminal on the phone .. Pin the middle of the virtual pin replacement battery is BSI (Battery Size Insdicator) is useful for HP Nokia.
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