Sabtu, 29 Oktober 2011

Mini-micro hydropower

The flow of water that flows from the highlands towards the more lace has a potential energy that can be utilized as a source of new energy. With good planning strategy for the development of energy sources such as this in turn will be able to overcome the problem of energy crisis in various places. But due to lack of planning several projects in the strategy development of alternative energy sources has not been obtained optimal benefits. often Power Plant construction project Mini-micro hydropower (MHP) there are various constraints such as low load factor, Surveying incomplete data availability and the lack of participation of surrounding communities, this led to the expected benefits from the potential of renewable energy sources has not been optimal. Therefore it needs a presence of an improvement.

Power micro hydro power

Generating a mini-micro hydro power plants are basically constructed in order to program the Village Electrical Sign (LISDES) with the utilization of hydropower resources. The construction project is primarily directed to remote areas unreachable grid. Generation is done by utilizing the flow of water from the tributaries are small or of irrigation channels. One of the factors that draw power from the mini-micro hydro is a relatively simple technology. However, if the feasibility study before the implementation of development projects is not adequate then the consequences become less efficient operation of the generation can not even operate at all.

Micro hydro is a generator that can generate electrical energy up to 100 KW while for a power plant that can produce electrical energy equal to 100 KW - 5 MW are defined as micro-hydro power plant. Mini-micro hydro power potential in Indonesia about 7,500 MW with an installed capacity of 200 MW. According to Central Statistics Agency (BPS) in 2000, about 60% of Indonesia's population live in remote villages. The number of villages in Indonesia as many as 58,545 villages, until the end of December 2000 which had as many as 49,155 villages have electricity.

Advantages micro hydro power plants

Some of the advantages of mini-micro hydro energy from others (Das, 2002) is:

· Clean Environment

· Renewable energy

· Not to consumptive water use

· Easy to operate as base load and peak load (can be quickly on / off)

· Cost low operating

· Durable (Long Life)

· Ideal for remote areas

Most of the mini-micro hydro development projects aimed to remote areas that have not passed by the grid. Problems develop when these arise as a result of the economical factors. Electrical energy consumption by rural communities generally ranges between 4-5 hours per day or 14-16% of installed power. The low energy consumption (load factor) is caused by the use of only as a mere illumination lamps. Economy aspects of power generation mini-micro hydro can be achieved with a careful plan by involving the participation of local communities are actively since the beginning of project development and integration of the apparatus with the village residents.

Besides generating a mini-micro hydro power plants have their own transmission and distribution network operation and management which can be referred directly to the local village board through cooperative enterprise. As an example of the success of the mini-micro hydro project in China because of high levels of electrical energy consumption by a factor of the load reaches 50-60% of installed power capacity and its management handed over to cooperatives.

Simple model intended use of electric energy produced to achieve load factors of more than 50% are as follows:


· Grinding of agricultural products

· Cooking

· Small Industries (cooling, distillation, etc.)

Afternoon Day:

· Lighting

· Home appliances

Night Day:

· Hatching eggs

· Fumigation fish

· Drying of agricultural products

Installation Type MHP

Broadly speaking MHP installation types can be grouped into two. Include the installation of mountainous areas and the installation of a flat area.

a. This type of installation for mountainous areas generally consist of the following components:

1. Door collection (Intake / Diversion)

2. Bath deposition (Desilting Tank)

3. Dissipation channel (Headrace)

4. Bak tranquilizers (Forebay)

5. Rapid pipe (penstock)

6. Building Plant (Power House)

7. Discard channel (Tailrace)

8. Transmission Network (Grid Line)

b. Installation of Flat Area

This type of installation for flat areas generally consist of the following main components:

Door collection (Intake / Diversion)

Channel Power (Power Canal)

Dissipation channel (Headrace)

Building Plant (Power House)

Discard channel (Tailrace)

Transmission Network (Grid Line)

Selection of Technology

Selection of technology in the construction of mini-micro hydro mainly lies in the selection of the main components of the turbine and generator. This is due to the area to be installed mini-micro hydro power plants have characteristics spesification.

a. type of hydropower turbine depends on the head and discharge water. For mountain areas that have low discharge height with high head turbine type is more suitable for use while in a flat area with a large discharge of water can use this type of canal drop low head turbine.

b. Types of Generators, In general there are two types of generators used in MHP, ie synchronous generators and induction generators.

Synchronous generators working on changing speeds. To be able to keep the generator speed remains, use an electronic speed governor. Generators of this type can be used directly and does not need another power grid as early movers. Highly suitable for use in remote villages with insulation systems.

Induction generators, is not required system voltage regulation and speed. However, this type of generator can not work alone because it requires an electrical grid system as early movers. Generators of this type are more suitable for areas that have been passed by the power grid (Grid System).


A micro hydro power projects are continuing to consider the following factors:

1. Planning in the choice of technology must be supported by concrete data, simply and can be accounted accountability.

2. The need for utilization of electrical energy for productive activities in the afternoon and evening in an optimal

3. The existence of local community participation through the establishment of proper management organization, between society and the institutions or agencies.
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Senin, 24 Oktober 2011


LM1830 based liquid level indicator circuit. LM1830 is a monolithic integrated circuit that can be used in liquid level indicator / control systems. Manufactured by National Semiconductors, the LM1830 can detect the presence or absence of polar fluids . Circuits based on this IC requires minimum number of external components and AC signal is passed through the sensing probe immersed in the fluid. Usage of AC signal for detection prevents electrolysis and this makes the probes long lasting. The IC is capable of driving a LED, high impedance tweeter or a low power relay at its output. The circuit of a low liquid level indicator with LED is shown above. Capacitor Ct sets the frequency of the internal oscillator. With the give value of C1 the frequency will be around 6KHz. Capacitor Cb couples the oscillator output to the probe and it ensures that no DC signal is applied to the probe. The circuit detects the fluid level by comparing the probe to ground resistance with the internal reference resistor Rref. When the probe to ground resistance goes above the Rref the oscillator output is coupled to the base of the internal output transistor making it conducting.


Sweep-Frequency Generator The working of a sweep-frequency generator is explained in the article below. The working and block diagram of an electronically tuned sweep frequency generator and its different parameters are also explained. Related Article SIGNAL GENERATORS A sweep frequency generator is a type of signal generator that is used to generate a sinusoidal output. Such an output will have its frequency automatically varied or swept between two selected frequencies. One complete cycle of the frequency variation is called a sweep. depending on the design of a particular instrument, either linear or logarithmic variations can be introduced to the frequency rate. However, over the entire frequency range of the sweep, the amplitude of the signal output is designed to remain constant. Sweep-frequency generators are primarily used for measuring the responses of amplifiers, filters, and electrical components over various frequency bands. The frequency range of a sweep-frequency generator usually extends over three bands, 0.001 Hz – 100 kHz (low frequency to audio), 100 kHz – 1,500 MHz (RF range), and 1-200 GHz (microwave range). It is really a hectic task to know the performance of measurement of bandwidth over a wide frequency range with a manually tuned oscillator.

Signal Generators In this article, the detailed explanation of a signal generator is given. The principles of signal modulation, the block diagram of an AM signal generator and the measures needed to achieve a stable frequency output is explained below. RELATED ARTICLE SWEEP FREQUENCY GENERATOR Like an oscillator, a signal generator is also a source of sinusoidal signals. The main difference between a signal generator and an oscillator is that a signal generator is capable of modulating its sinusoidal output signal with other signals. When signal generators are used for producing an unmodulated sinusoidal output they are said to be producing continuous height wave [CW] signal. When the produced output signal is modulated, the modulating waveforms may be either externally applied sine-waves, square waves, triangular waves, pulses or more complex signals, as well as internally generated sine-waves. Amplitude modulation (AM) or frequency modulation (FM) may be used. Normally amplitude (AM) modulation is employed. Principles of amplitude modulation (AM) and frequency modulation (FM) are illustrated in the figure shown below. Signal Modulaton Signal Generator – Applications Signal generators are primarily employed for providing appropriate signals for calibration, testing and troubleshooting of the amplifier circuits used in communication.
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IC NE555

The circuit diagram of a very simple voltage doubler using NE555 timer is shown here. Here IC NE555 is wired as an astable mutivibrator operating at around 9KHz. The base of the two transistors (Q1 and Q2) is shorted and output of the astable multivibrator (pin 3) is connected to it. When the output of astable multivibrator is low, Q1 will be OFF and Q2 will be ON. The negative terminal of the capacitor C3 will be shorted to ground through T2 and it will be charged to the input supply voltage. When the output of the astable multi vibrator is high, transistor Q1 will be ON and transistor Q2 will be OFF. The capacitor C4 will be charged to the voltage across capacitor C3 plus the input supply voltage (that is double the input voltage). This is how the circuit works. This voltage doubler circuit can deliver only up to 50mA output current and above that current limit the output voltage will be dramatically reduced.

NE555 timer IC are already published here and this is just another one.Here is the circuit diagram of a police siren based on NE55 timer IC. The circuit uses two NE555 timers ICs and each of them are wired as astable multivibrators.The circuit can be powered from anything between 6 to 15V DC and is fairly loud.By connecting an additional power amplifier at the output you can further increase the loudness. IC1 is wired as a slow astable multivibrator operating at around 20Hz @ 50% duty cycle and IC2 is wired as fast astable multivibrator operating at around 600Hz.The output of first astable mutivibrator is connected to the control voltage input (pin5) of IC2. This makes the output of IC2 modulated by the output frequency of IC1, giving a siren effect. In simple words, the output frequency of IC2 is controlled by the output of IC1. Circuit diagram. Notes. The circuit can be assembled on a Perf board. I used 12V DC for powering the circuit. Instead of using two NE55 timer ICs, you can also use a single NE556 timer. NE556 is nothing but two NE555 ICs in one package.

P-N junction

Zener diode is a P-N junction diode specially designed to operate in the reverse biased mode. It is acting as normal diode while forward biasing. It has a particular voltage known as break down voltage, at which the diode break downs while reverse biased. In the case of normal diodes the diode damages at the break down voltage. But Zener diode is specially designed to operate in the reverse breakdown region.

The basic principle of Zener diode is the Zener breakdown. When a diode is heavily doped, it’s depletion region will be narrow. When a high reverse voltage is applied across the junction, there will be very strong electric field at the junction. And the electron hole pair generation takes place. Thus heavy current flows. This is known as Zener break down.

So a Zener diode, in a forward biased condition acts as a normal diode. In reverse biased mode, after the break down of junction current through diode increases sharply. But the voltage across it remains constant. This principle is used in voltage regulator using Zener diodes.
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Rectifier diodes

Rectifier diodes are the most commonly used diode type but other diodes come into play as well. These include Zener diodes, Schottky diodes, tunnel diodes, photodiodes, varicap diodes and light-emitting diodes. Each diode type has a different function. For example, Zener diodes control voltage, Shottky diodes work in switch circuits, light-emitting diodes are in lighting and video display circuits. Photodiodes are in light-detection circuits. A "varicap" diode is constructed like a diode but behaves as a variable capacitor.

Rectifier Tesla ham

Bridge Diode Rectifier KBL406

Voltage Diode HV HF Rectifier

Recovery Diode Rectifier Stack
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Jumat, 07 Oktober 2011

EM DC Amplifier

EM DC Amplifier model A22 is a low noise amplifier module for sensitive DC measurements, data collection and systems, and is ideal for very sensitive temperature measurement using thermocouples.
The noise level of the A22 is equivalent to a perfect resistor of about 150 ohms.
When used with normal type thermocouples for temperature measurement, sensitivities of around 20 micro-Kelvin can be achieved. The input voltage drift is very low and is compatible with voltage sensitivities of about 1 nanovolt.
The A22 has many other features desirable in a measurement amplifier. The very high loop voltage gain of 100T, or 280dB, means that high overall gain may be used, controlled precisely by feedback resistors, thus ensuring good linearity, with the accuracy defined by the feedback resistors used.
Despite the high gain, the model A22 is stable with 100% feedback, thus allowing feedback capacitors to be used to filter the output. The input signal level can be up to plus or minus 20 milli-volts and the output can be up to plus and minus 3 volts.
The response time of the A22 is fast, and the gain is reduced to unity at about 20 kHz, thus ensuring good response times, even at high gain settings.
The power supply requirement is low, being about 1.2 milli-amps with power supplies of plus and minus 6 volts, making it ideal for multi-channel measurement systems.
The A22 is designed to be mounted on a printed circuit board, using a 0.1” grid, with 13 pin connections on a rectangle 1.6” X 1.2”, and is built into a heavy gauge mumetal case which gives it very good magnetic, electrostatic and thermal immunity from interference. A printed circuit board is available which provides connections for power supply, gain, filter capacitors and outputs. It also contains controls for voltage and current offsets, power supply de-coupling and a passive output filter to reduce any modulation by-product.
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AQ4X90 Amplifier

Model AQ4X90
Digital Four Channel Amp

Input Sensitivity 0.2V ~ 8V
Signal to Noise Ratio 100 <
Damping Factor 250 <
External Fuse Rating 2 x 30Amp
Tested Voltage and THD 14.4V & 1% THD
4 ohm Power 90W x 4
2 ohm Power 120W x 4
4 ohm Mono Power 240W x 2
Channel 1 and 2:

Variable X-over 45 Hz (450Hz) ~ 450Hz (4.5KHz) at 12dB/Oct.
X-over Multiply x 1, x 10
X-over Selector Clone 3/4/FULL/HPF
Channel 3 and 4:

Subsonic Filter 10~360 Hz at 12 dB/Oct.
Bass Boost 0~12 dB
Variable X-over 45 Hz (450Hz) ~ 450Hz (4.5KHz) at 12dB/Oct.
X-over Multiply x 1, x 10
X-over Selector LPF-BP /HPF-FULL
Outputs Line Out
Dimensions (mm) 350mm (L) x 238mm (W) x 59.6mm (H)
Dimensions (in) 13.78in (L) x 9.37in (W) x 2.35in (H)
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XLS Series amplifiers

XLS Series amplifiers are professional Stereo power amplifiers engineered to meet demanding Audio requirements - reliably and within budget. Every XLR Series Amplifier is backed by Crown's unequaled three-year, no-fault, fully transferable warranty that covers everything.

With over five decades of experience designing and building rock-solid products, Crown is the standard in Amplifier technology. So check out the affordable Crown XLS Series.

Crown CT4150 Specifications:
Sensitivity: 1.4V
RATED POWER OUTPUT: 125W per Channel into 8 Ohms
Signal to Noise Ratio (below rated power 20Hz to 20kHz, A-Weighted): 110dB
Total Harmonic Distortion (THD) (full rated power, 20Hz - 20kHz): < 0.05% INTERMODULAR DISTORTION (from 0dB down to -40dB): < 0.05% Frequency Response (at 1W into 4/8 Ohms): +/- 0.5dB CROSSTALK (below rated power 20Hz to 1kHz): > 70dB
COMMON MODE REJECTION (20Hz to 1kHz): > 55dB, typically > 70dB
DIMENSION (H x W x D): 1.75" x 19" x 14.25"
NET WEIGHT: 10 lbs/4.54 kg
NET SHIPPING WEIGHT: 15 lbs/6.8 kg
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PWM amplifier chips

PWM amplifier chips requires an analysis of performance specifications. Output current is the maximum continuous current that can be delivered in the output. Input offset voltage is the amount of DC voltage that amplifiers produce even when 0 V is applied to the input. The supply voltage range includes minimum and maximum amounts. Internal power dissipation is the maximum amount of power that can be safely supported. Quiescent current is produced during normal operation. The power bandwidth or large-signal bandwidth describes an amplifier’s ability to provide a maximum output voltage swing with increasing frequency. The peak output swing is the output voltage at the frequency which represents the upper limit of the power bandwidth. A high switching frequency allows smaller output filters to be built into the amplifier enclosure. Typically, suppliers list the switching frequency for PWM amplifier chips as a maximum amount.

PWM amplifier chips are available in a variety of integrated circuit (IC) package types and with different numbers of pins. Basic IC package types include single in-line package (SIP), dual in-line package (DIP), discrete package (DPAK), small outline package (SOP), and quad flat package (QFP). Many packaging variants are available. For example, common SOP variants include shrink small outline package (SSOP) and thin shrink small outline L-leaded package (TSSOP). Small outline integrated circuit (SOIC) packaging is also available for PWM amplifier chips. TO-3 is a transistor outline (TO) package with three leads. TO-92, another transistor outline package, is often used for low power devices. By contrast, TO-220 is suitable for high power, medium current, and fast-switching power devices.
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log amp chips

Logarithmic amplifier chips (log amp chips) produce an output voltage that is directly proportional to the logarithm of the input voltage. Operational amplifier chips (op amp chips) are general-purpose, closed loop devices used to implement linear functions. They compare two incoming signals and release a third that is an amplified measure of the difference between the two. Power operational amplifier (POA) chips are used to increase the power of low-level signals in applications that drive low impedances or reactive loads. Pulse width modulated (PWM) amplifier chips generate a current that switches between high and low output levels. Sample-and-hold amplifier chips freeze analog voltage instantly. During this process the HOLD command is issued and analog voltage is available for an extended period. Specialized amplifier and comparator chips are also available.

Amplifier and comparator chips differ in terms of performance specifications and available features. Specifications for differential amplifier chips include bandwidth, gain, minimum gain, supply voltage, supply current, offset voltage, slew rate, and harmonic distortion (second and third harmonics).

Features include number of leads, package type, and power-down options. Specifications for instrumentation amplifier chips include input common-mode voltage range to negative rail, rail to rail (input or output), gain, minimum stable closed loop gain, maximum supply current, maximum voltage offset, typical common mode rejection ratio, typical power supply rejection ratio, maximum input bias current, typical unity gain bandwidth, typical slew rate, input voltage noise, and input current noise.
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RF amplifiers

RF amplifiers requires an analysis of several performance specifications. Operating frequency is the frequency range for which RF amplifiers meet all guaranteed specifications. Design gain, the ratio of the output to the input power, is normally expressed in decibels (dB), or Gdb = 10 * log (Po/Pi). Output power is the signal power at the output of the amplifier under specified conditions such as temperature, load, voltage standing wave ratio (VSWR), and supply voltage. Gain flatness indicates the degree of the gain variation over its range of operating wavelengths. Secondary performance specifications to consider include noise figure (NF), input VSWR, output VSWR, and monolithic microwave integrated circuit (MMIC) technology. The noise figure, a measure of the amount of noise added to the signal during normal operation, is the ratio of the signal-to-noise ratio at the input of the component and the signal-to-noise ratio measured at the output. The NF value sets the lower limit of the dynamic range of the amplifier. Input VSWR and output VSWR are unit-less ratios ranging from 1 to infinity that express the amount of reflected energy.

There are several physical and electrical specifications to consider when selecting RF amplifiers. Physical specifications include package type and connector type. Package types include surface mount technology (SMT), flat pack, and through hole technology (THT). RF amplifiers may also be connectorized or use waveguide assemblies. Connector types include BNC, MCX, Mini UHF, MMCX, SMA, SMB, SMP, TNC, Type F, Type N, UHF, 1.6 / 5.6, and 7/16. Important electrical characteristics include nominal operating voltage and nominal impedance. Operating temperature is an important environmental parameter to consider.
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4 ohm speaker

The "50watts" part is the one we notice first and everything else qualifies how that "50watts" was measured. Having enough power is what most people look for in an amp. However, other things come into play. If the you are going to run a load less than 4 ohms, then the current capability of the amp is definitely important and most specs do not give a current capability. A power rating into 2 ohms can help though. If the power doubles into 2 ohms then you know that the amp is built strongly enough that it can deliver enough current to drive a 2 ohm load. You may think that this is not important if you are not going to drive 2 ohm loads but it is important. Speakers (woofers, midranges, tweeters, etc) are not purely resistive. They have capacitive and inductive properties as well. Depending on the music and your setup, the impedance may dip well below 4 ohms for a nominally 4 ohm speaker.
Whether you amp can supply current fast enough to reproduce the music faithfully depends partially on the amp's slew rate (how fast its output can change), its damping factor (how easily it can control the speaker) and its current capability. For these reasons 2 ohm power is important even when driving 4 ohm speakers. Slew rates of 100V/microsec and damping factors above 100 (referenced with a 4 ohm load) are good but that information is usually not given out by the amp manufacturer. I hope it is clear now that the number of watts an amp can produce is only one factor in determining whether an amp is capable of the performance you desire.
On a final note on this part of the spec, most head units use IC (integrate circuits or chips) for the built-in amp's output stage. Those chips rarely can provide adequate current which is why even most novices know not drive subwoofers from a head unit. Real amps often have ICs in them as well but the output stages are almost always discrete, meaning they are built from transistors, resistors, capacitors and not integrated together inside tiny ICs. Advances in IC technology always making them better though.
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two terminals

Bi-Amping refers to using different amplifiers (or different channels of the same amp) for the low and high frequencies in the same speaker. On a 3-way speaker, usually the mid and tweeter are driven by one amp, and the woofer is driven by more powerful amp. This allows you to purchase a high quality low power amp for the highs, and a more powerful amp for the lows. With the proper pre-amp you can also have more control over the bass output. On a 2-way speaker, the mid and tweeter are driven by different channels on an amp. This is usually done so that you can use an active crossover before the amplifier.
In DIY audio, bi-amping has even more advantages. Low pass crossovers for woofers require very large inductors. These inductors are basically very long coils of copper wire which can have a very high resistance. Using an active crossover before the amplifier removes the need for these inductors. Bi-amping also removes the need for any circuits to fix problems caused by different sensitivities or impedances between drivers.
If a speaker is capable of bi-amping, then the plate on the back of the speaker will have 4 binding posts: 2 + terminals and 2 - terminals. Both + terminals and both - will have a piece of metal connecting them together. To bi-amp the speaker, remove the metal piece. Then, use the top 2 terminals for the high frequency amp, and the bottom two terminals for the bass amp.
Note: some professional audio equipment has 4 binding posts on the back. This is for ease of running multiple speakers in parallel. It is not for bi-amping, and the terminals should not be connected.
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Selasa, 04 Oktober 2011

Laser diodes

Laser diodes are used in all areas of electronics from domestic equipment, through commercial applications to hash industrial environments. In all these applications laser diodes are able to provide a cost effective solution while being rugged and reliable and offering a high level of performance.

Laser diode technology has a number of advantages:
Power capability: Laser diodes are able to provide power levels from a few milliwatts right up to a few hundreds of watts.
Efficiency: Laser diode efficiency levels can exceed 30%, making laser diodes a particularly efficient method of generating coherent light.
Coherent light: The very nature of a laser is that it generates coherent light. This can be focussed to a diffraction limited spot for high density optical storage applications.
Rugged construction: Laser diodes are completely solid state and do not require fragile glass elements or critical set-up procedures. Accordingly they are able to operate under harsh conditions.
Compact: Laser diodes can be quite small allowing for laser diode technology to provide a very compact solution.
Variety of wavelengths: Using the latest technology and a variety of materials, laser diode technology is able to generate light over a wide spectrum. The use of blue light having a short wavelength allows for tighter focussing of the image for higher density storage.
Modulation: It is easy to modulate a laser diode, and this makes laser diode technology ideal for many high data rate communications applications. The modulation is achieved by directly modulating the drive current to the laser diode. This enables frequencies up to several GHz to be achieved for applications such as high-speed data communications.
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