Showing posts with label how. Show all posts
Showing posts with label how. Show all posts
Tuesday, May 14, 2013
Electric Vehicles How Far Have We Come in 100 Years
If you want to get a sense of how far the electric car market has really come, its instructive to read "Foreign Trade in Electric Vehicles," an article available on the New York Times Website.
In glowing terms, the article describes the future of electric cars. The vehicle "has long been recognized as the ideal solution" and is "cleaner and quieter" than other cars, as well as "more economical." The article also praises the electric vehicle (EV) battery. "It is simple, light, easy to take care of and far more efficient than the old lead battery," and the new battery "solves the problem of electric transportation."
An Edison storage battery in test setup, from the 1916 monograph "The Edison Alkaline Storage Battery," by the technical staff of the Edison Storage Battery Co.
The article is dated Nov. 12, 1911 -- 100 years ago this month.
Its hard to look at the article and not wonder how far weve come. Yes, the EV is back. Nissan has its Leaf. Ford has two EVs coming out soon. General Motors has announced the Spark EV and has the Chevy Volt, an electric car that burns gasoline part of the time. Tesla plans to roll out the Model S soon and is working with Toyota on an electric RAV4. Mitsubishi has its i MiEV. Even DeLorean has announced an electric car.
But the EV battery... has it really advanced much in the past 100 years? In a 1998 Design News article, battery makers discussed the creation of a lithium-ion battery with an energy density of 90Wh/kg. Thirteen years later, the Nissan Leaf battery is rated at 140Wh/kg -- a 55% increase. Thats not bad, but is it enough to make the EV battery a serious competitor with gasoline, which offers 80 times as much energy and a five-minute refueling capability?
Moreover, theres the issue of cost. In the 1998 Design News article, engineers set a target of $100/kWh to make EV batteries more competitive. Today, the cost figure still hovers between $800 and $1,000/kWh.
Because the costs are so high, most EV makers are using the higher energy densities to reduce the size of their batteries. Instead of a bulky 900-pound unit, theyre employing higher-energy packs of about 400 or 500 pounds. But the flip side of that strategy is that EV range hasnt changed much. If we go back to the 1998 Design News article, we see the ranges as follows:
Chrysler Epic minivan: 68 miles.
Ford Ranger EV: 58 miles.
GM EV1: 90 miles.
GM S-10 electric pickup: 45 miles.
Toyota RAV4 EV: 118 miles.
Now contrast that with todays Nissan Leaf. Nissan says its 2011 Leaf travels 100 miles between charges. (The EPA rates it at 73.)
Many EV proponents have explanations for all this. A popular one is the "big oil conspiracy." According to this logic, oil executives have conspired with automakers to suppress development of EVs over the years. Numerous Websites are dedicated to explaining this conspiracy. However, they have not explained why our universities have had limited luck in creating a revolutionary battery over the past 100 years.
The truth is that the EVs real gains have been in speed and performance. On drag strips around the country, EV converters are turning quarter-mile times as low as 10 seconds using old Ford Pintos and Datsuns. The old GM EV1 was said to have hit a speed of more than 180mph, and the White Lightning racing EV reached 245mph. If Thomas Edison (who invented the battery discussed in the 1911 New York Times article) could see the performance of todays EVs, hed be astounded.
Still, Edison might be equally surprised by the lack of advancement in the area of battery energy. Many potential buyers are still turned off, not only by the cost, but by the pure EVs inability to make long trips. Bill Reinert, national manager of advanced technology vehicles for Toyota, said it best this year, when he told us: "Even if Im covered 90% of the time, Im probably unlikely to make a [buying] decision that leaves me uncovered 10% of the time."
Obviously, researchers are working on the energy issue, but their efforts would be best flavored with a little public patience. If the 100-year-old New York Times article teaches us anything, its that vehicle electrification could still be a long, arduous journey.
Monday, April 8, 2013
How to Create 1000 Watt Power Amplifier
Power amplifier has up to 1000 Watt power, this circuit made one channel only so if you want to create a stereo in it must be made one again, actually this is more suitable power amplifier in use for Sound System or outdoor, so if only in use for the house I think is less suitable.
Maybe youve seen or even have an active speaker and there is written 1500 watts PMPO (Peak Music Power Output), make no mistake this is different from Power Amplifier Active Speaker, I often dismantle such Active Speaker in it only a power with power no more than 150 watts by using the transformer 2-3 Ampere. PMPO is not a real power which is issued by the Power Amplifier, but counting all the speakers that there is, for example: if there are 5 pieces of speakers on each channel and each speaker has a power of 10 W then it is 100 W PMPO.
Maybe youve seen or even have an active speaker and there is written 1500 watts PMPO (Peak Music Power Output), make no mistake this is different from Power Amplifier Active Speaker, I often dismantle such Active Speaker in it only a power with power no more than 150 watts by using the transformer 2-3 Ampere. PMPO is not a real power which is issued by the Power Amplifier, but counting all the speakers that there is, for example: if there are 5 pieces of speakers on each channel and each speaker has a power of 10 W then it is 100 W PMPO.
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| 1000W Power Amplifier schematics |
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| Part List 1000W amplifier |
While this 1000 Watt Power Amplifier minimal use transformer 20 Ampere. And the output of Power Amplifier DC voltage contains approximately 63 volts, with currents and voltages of this magnitude, this 1000 Watt Power Amplifier will not hesitate hesitate to destroy your woofer speakers to connect. To overcome that then before the speaker on connects to 1000 Watt Power Amplifier must be in pairs Speaker Protector.
Actually if you want to create a Power Amplifier with great power does not have to make a Power Amplifier with great power. Example: you want to create a Power Amplifier with 10 000 Watt power. You do not have to assemble a Power Amplifier with power of 10,000 watts, but you assemble the power Power Amplifier Small but many, such as you assemble the Power Amplifier with 1000 Watts of power for as many as 10 pieces, it will produce 10 000 Watt Power Amplifier helpless.
Circuit uses power transistors pair of 5 x 5 x 2SA1216 and 2SC2922 and 2SC1583 use a differential amplifier that actually contains 2 pieces of transistors that are in containers together. Why use such built-in amplifier differental tujuanya so identical / similar, could have uses 2 separate transistors but can result in amplifier so it is not symmetrical.
Tips combining speaker.
To get the speakers with great power combining techniques can be used in parallel series, combining each group of speakers should sepaker they will have the same impedance, the same type (Woofer, Mid Range or tweeter) and the same power. Number of merging these speakers should consists of 4 , 9, 16 ff, see picture
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| Speaker wiring |
Example: The number of speakers have 4 pieces each of its 200 Watt power generated will be a speaker at = 200 x 4 = 800 Watt. If there are 9 speakers 200 W then the result = 9 x 200 W = 1800 Watt.
Tuesday, March 19, 2013
How to Make 1 A Constant Current LED Driver Circuit
The article explains a simple circuit using the IC MBI6651 from MACROBLOCK. The IC has been specifically designed for operating high power LEDs safely by providing a constant current output. The circuit includes very few external components and therefore becomes very easy to assemble at home.
About the IC MBI6651
The IC MBI6651 is a high efficiency, step down DC to DC converter chip capable of driving high power LEDs at a safe 1 Amp constant current.
The IC requires just four passive external components for making it functional.
The output current of the IC can be externally set by selecting the appropriate resistor value.
The IC also features a PWM controlled dimming control of the connected LEDs.
Some of the other outstanding features of this IC includes UVLO meaning under voltage lockout, over temperature shut down, LED open circuit protection and LED short circuit protection, all these ensure complete safety to the IC from wrongly configured output loads.
Typical Application of this device are:
Automotive decoration and illumination
LED flood lights using high intensity, high power LED.
The IC also can be used as a constant current source in particular circuit applications.
Setting the output Current
The output current of the IC is fixed through an external resistor Rsen. The output current Iout and the adjustment resistor Rsen has the following relation:
Given Vsen=0.1V
Rsen=(Vsen/Iout)=(0.1V/Iout)
Where Rsen is the value of the external resistor. This resistor is connected across the pin outs SEN and Vsen of the IC.
The optimum current with Rsen 0.1 Ohms is 1000 mA or 1 Amp.
Optimizing External Component Selection
Inductor: Two issues specify the inductor type, the switching frequency and the ripple current. The involved calculation can be written as:
L1>{Vin - Vout - Vsen - (Rds(on) * Iout)} * D/fsw * delta.IL
where, Rds(on) is the on-resistance of the ICs internal MOSFET. The value is typically around 0.45 at 12V
D is the duty cycle of the IC, given as D = Vout/Vin
fsw is the switching frequency of the IC
While designing the inductor for the given circuit, along with the inductance the saturation current must also be taken into account,because these are two basic factors which typically affects the overall performance of the circuit.
The rule of thumb, the saturation current of the inductor should be selected 1.5 times greater than the LED current.
Moreover, selecting high values for the inductance provides better line and load regulation.
Refer circuit diagram
Selecting the Schottky diode
The diode D1 shown in the circuit diagram basically acts as the flywheel diode for nullifying the inductor back emf during the periods when the LED is switched OFF.
The diode must be selected with the following couple of important characteristics:
It should have a low forward voltage rating and maximum possible reverse voltage tolerance.
Selecting the capacitor
The general rule is always to select a capacitor value with a voltage tolerance 1.5 times higher than the supply voltage.
Preferably, a tantalum capacitor should be selected because these have high capacitance and low ESR characteristics.
The proposed circuit of 1 Amp constant current LED driver circuit is given below:
The basic operating parameters are given below:
Pin Out Specs:
About the IC MBI6651
The IC MBI6651 is a high efficiency, step down DC to DC converter chip capable of driving high power LEDs at a safe 1 Amp constant current.
The IC requires just four passive external components for making it functional.
The output current of the IC can be externally set by selecting the appropriate resistor value.
The IC also features a PWM controlled dimming control of the connected LEDs.
Some of the other outstanding features of this IC includes UVLO meaning under voltage lockout, over temperature shut down, LED open circuit protection and LED short circuit protection, all these ensure complete safety to the IC from wrongly configured output loads.
Typical Application of this device are:
Automotive decoration and illumination
LED flood lights using high intensity, high power LED.
The IC also can be used as a constant current source in particular circuit applications.
Setting the output Current
The output current of the IC is fixed through an external resistor Rsen. The output current Iout and the adjustment resistor Rsen has the following relation:
Given Vsen=0.1V
Rsen=(Vsen/Iout)=(0.1V/Iout)
Where Rsen is the value of the external resistor. This resistor is connected across the pin outs SEN and Vsen of the IC.
The optimum current with Rsen 0.1 Ohms is 1000 mA or 1 Amp.
Optimizing External Component Selection
Inductor: Two issues specify the inductor type, the switching frequency and the ripple current. The involved calculation can be written as:
L1>{Vin - Vout - Vsen - (Rds(on) * Iout)} * D/fsw * delta.IL
where, Rds(on) is the on-resistance of the ICs internal MOSFET. The value is typically around 0.45 at 12V
D is the duty cycle of the IC, given as D = Vout/Vin
fsw is the switching frequency of the IC
While designing the inductor for the given circuit, along with the inductance the saturation current must also be taken into account,because these are two basic factors which typically affects the overall performance of the circuit.
The rule of thumb, the saturation current of the inductor should be selected 1.5 times greater than the LED current.
Moreover, selecting high values for the inductance provides better line and load regulation.
Refer circuit diagram
Selecting the Schottky diode
The diode D1 shown in the circuit diagram basically acts as the flywheel diode for nullifying the inductor back emf during the periods when the LED is switched OFF.
The diode must be selected with the following couple of important characteristics:
It should have a low forward voltage rating and maximum possible reverse voltage tolerance.
Selecting the capacitor
The general rule is always to select a capacitor value with a voltage tolerance 1.5 times higher than the supply voltage.
Preferably, a tantalum capacitor should be selected because these have high capacitance and low ESR characteristics.
The proposed circuit of 1 Amp constant current LED driver circuit is given below:
The basic operating parameters are given below:
Pin Out Specs:
Courtesy: http://www.ledlabs.ru/pdf/macroblock/mbi6651.pdf
Wednesday, March 6, 2013
How to Make Any Light a Strobe Light Using Just Two Transistors
If you feel strobe lights very interesting but are disappointed by the fact that these wonderful light effects can be produced only through complex xenon tube then probably you are quite mistaken. It is very much possible to make any light a strobe light if you are equipped with a proper driving circuit capable of handling different lighting devices to generate the desired strobe light effect. The present article shows how a circuit as basic as a multivibrator may be modified in different ways and made compatible with ordinary bulbs, lasers, LEDs to produce spectacular light pulses.
A strobe light may be used for warning, scientific analysis or as an entertainment device, whatever may be the application the effects are simply dazzling. In fact it is possible to make any light a strobe light through a proper driving circuit. Explained with Circuit Schematics.
Introduction
A light when made to blink or flash indeed looks pretty eye-catching and that’s the reason why they are used in number of places as a warning device or for decorations. However a strobe light in particular may also be considered a flashing light yet is uniquely different from ordinary light flashers. Unlike them in a strobe light the ON/OFF pattern is so optimized that it produces sharp dazzling pulsed flashes of light. There’s no doubt why they are mostly used in conjunction with fast music to enhance a party mood. Nowadays green lasers are being popularly used as a strobing device in party halls and gatherings and have become hot favorite among the new generation. Whether it’s LEDs, lasers or an ordinary filament bulb, all can be made to flash or rather strobe using an electronic circuit capable of producing the required pulsed switching in the connected lighting element. Here we will see how we can make any light a strobe light using a simple electronic circuit.
The following section will acquaint you with the circuit details. Let’s go through it.
Pulsating any Light to Produce Strobing Effect
Through one of my previous articles we came across a nice little circuit able to produce interesting strobe effects over a few of the connected LEDs. But this circuit is only suitable for driving low power LEDs and thus cannot be applied to illuminate big areas and premises. The proposed circuit allows you to drive not only LEDs but also powerful lighting agents like incandescent bulbs, lasers, CFLs etc.
The first diagram shows the most basic form of a multivibrator circuit using transistors as the main active components. The connected LEDs can be made to strobe by suitably adjusting the two potentiometers VR1 and VR2.
The above circuit forms the base for all the following circuits through some suitable modifications and additions.
For example if you want to illuminate and pulsate a small torch bulb using it, you would just need to do the simple modifications as shown in the second diagram. Here by adding a PNP power transistor and triggering it through the collector of T2, a torch bulb is easily made to strobe. Off course, optimum effect is achieved only through proper adjustment of the two Pots.
As already discussed already in the previous section, green laser pointers are pretty popular nowadays; the diagram illustrated shows a simple method of converting the above circuit into a pulsating green laser pointer strobe light. Here, T3 and T4 form a typical current controlled transistor configuration – a must when vulnerable lasers are involved. The selection of R6 can be critical and will decide the current limiting threshold for a safe operating of the laser. A wrong calculation may instantly roast your costly laser bulb. The following formula may be used for calculating R6:
U = 0.6/Ilaser,
Where U = Operating voltage of the laser and the circuit.
I (laser) = Maximum safe operating current of the laser device.
The next diagram shows how an AC mains lamp may be used as a strobing light source using the above circuit. Here a triac forms the main switching component receiving the required gate pulses from T2’s collector.
Thus we see that through the above circuit designs it becomes very easy to make any light a strobe light simply by doing the relevant modifications.
Parts List
R1, R4, R5 = 680 Ohms,
R2, R3 = 10K
VR1, VR2 = 100K pot
T1, T2 = BC547,
T3, T4 = BC557
C1, C2 = 10uF/25V
Triac = BT136
LEDs = as per choice
Parts List
R1, R4, R5 = 680 Ohms,
R2, R3 = 10K
VR1, VR2 = 100K pot
T1, T2 = BC547,
T3, T4 = BC557
C1, C2 = 10uF/25V
Triac = BT136
LEDs = as per choice
Saturday, March 2, 2013
How to Make a Cheap LED Name Plate with Illuminated Back Light
LEDs are no doubt gaining popularity by leaps and bounds and probably most of the illuminated decorative articles today incorporate LED as the light source. These devices are relatively cheap, extremely bright and outstandingly efficient with their operations.
Digital displays today also incorporate LED technology and we all know how impressive they look with the involved digits distinctly visible with an illuminated back light.
The back illumination especially gives a fuller look and helps to highlight the display in a better way.
However these displays can be pretty expensive and require microcontroller ICs for producing the involved illuminations. A new hobbyist may find it difficult to grasp and make such displays at home.
Using LEDs in series for designing alphanumerical displays consisting of the desired names and numbers looks good but these dont produce the effects which is generally obtained from a back illuminated displays.
A cheap way of making a back illuminated display or a name plate having the desired alphabets is explained here, lets see how we can implement the whole concept very cheaply.
For making the proposed back illuminated name plate circuit design we will basically require the following very few of the components.
Four high bright LEDs, color will depend on the user preference, I used blue LEDs in my prototype because my party wanted blue back light illumination for his displays.
A rectangular plastic lens, made up of acrylic material.
PCB as shown in the figure.
Positive film of the desired name or, a screen printed film with the name portion kept transparent while the rest of the area painted black and opaque.
150 Ohm resistor, 1 no.
Refer circuit diagram
How to Make the Display.
Connect the LEDs and the resistor as shown in the figure below such that the LEDs focus the light across the length of the rectangular PCB.
Cut the acrylic lens such that it perfectly fits in between the LEDs, make notches or grooves at the lens ends for making a snug fitting with the LEDs.
Now scratch one of the surfaces of the acrylic lens with a polish paper or an emery paper, such that it becomes rough and grainy on that surface and almost opaque for a clear vision, this operation is the secret behind producing a perfect and uniform back light.
Place a white paper cut to size on the PCB such that the light from the LEDs floods the white paper across the length.
Next place the lens in the center of the LED, over the PCB and the above white paper with its roughened surface on the top side.
Next place the positive film of the name display over the above lens.
Switch ON power to the LEDs, wow! your name plate is glowing bright with an illuminated back-light thats uniformly lit across the whole displayed name.
Put insulation tape over the side ends of the unit such that light does not escape from these areas.
Enclose the whole unit inside a suitable rectangular box for displaying it in the preferred location.
PCB, LED and the Lens Set Up
Positive placed over the lens for the final illuminated get-up:
Now some glimpses of the actual prototype:
First, the PCB/LED design:
Completed Prototype, Switched ON:
In Dark:
Digital displays today also incorporate LED technology and we all know how impressive they look with the involved digits distinctly visible with an illuminated back light.
The back illumination especially gives a fuller look and helps to highlight the display in a better way.
However these displays can be pretty expensive and require microcontroller ICs for producing the involved illuminations. A new hobbyist may find it difficult to grasp and make such displays at home.
Using LEDs in series for designing alphanumerical displays consisting of the desired names and numbers looks good but these dont produce the effects which is generally obtained from a back illuminated displays.
A cheap way of making a back illuminated display or a name plate having the desired alphabets is explained here, lets see how we can implement the whole concept very cheaply.
For making the proposed back illuminated name plate circuit design we will basically require the following very few of the components.
Four high bright LEDs, color will depend on the user preference, I used blue LEDs in my prototype because my party wanted blue back light illumination for his displays.
A rectangular plastic lens, made up of acrylic material.
PCB as shown in the figure.
Positive film of the desired name or, a screen printed film with the name portion kept transparent while the rest of the area painted black and opaque.
150 Ohm resistor, 1 no.
Refer circuit diagram
How to Make the Display.
Connect the LEDs and the resistor as shown in the figure below such that the LEDs focus the light across the length of the rectangular PCB.
Cut the acrylic lens such that it perfectly fits in between the LEDs, make notches or grooves at the lens ends for making a snug fitting with the LEDs.
Now scratch one of the surfaces of the acrylic lens with a polish paper or an emery paper, such that it becomes rough and grainy on that surface and almost opaque for a clear vision, this operation is the secret behind producing a perfect and uniform back light.
Place a white paper cut to size on the PCB such that the light from the LEDs floods the white paper across the length.
Next place the lens in the center of the LED, over the PCB and the above white paper with its roughened surface on the top side.
Next place the positive film of the name display over the above lens.
Switch ON power to the LEDs, wow! your name plate is glowing bright with an illuminated back-light thats uniformly lit across the whole displayed name.
Put insulation tape over the side ends of the unit such that light does not escape from these areas.
Enclose the whole unit inside a suitable rectangular box for displaying it in the preferred location.
PCB, LED and the Lens Set Up
Lens Placed over the PCB
Example film positive of a particular display name:
Positive placed over the lens for the final illuminated get-up:
Now some glimpses of the actual prototype:
First, the PCB/LED design:
Completed Prototype, Switched ON:
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