Kamis, 17 November 2011

power supply outage

When the main power supply outage (PLN), the electricity supply required reserves and the conditions of the Generator-Set is expected to supply power mainly to priority loads. Generator can be used as a backup electrical system or "off-grid" (which depends on the resources the user needs). Generators are often used by hospitals and industries that require a steady source of power and reliable (high level of supply reliability), and also for rural areas that do not have access to commercially supplied electricity through the existing distribution network PLN.

A diesel engine generator set consists of:
1. Prime mover or mover first, in this case diesel engine (in English is called diesel engines)
2. Generator
3. AMF (Automatic Main Failure) and ATS (Automatic Transfer Switch)
4. Battery and Battery Charger
5. Panel ACOS (Automatic Change Over Switch)
6. Security for Equipment
7. Installing the Power Supplies

Diesel engine

Including diesel engines with internal combustion engines or motor fuel referred to, in terms of how to obtain thermal energy (heat energy). To generate electricity, a diesel engine connected to a generator in one axis (the axis of diesel engine is coupled with shaft generator).

An advantage of using diesel engines as a first mover:
* Design and installation is simple
* Auxilary equipment (auxiliary equipment) simple
* When loading a relatively short

Losses use diesel engines as early Mover:
* Weight machines are very heavy because it must be able to withstand vibration and high compression.
* Starting the initial weight, because the compression height is about 200 bar.
* The greater the power the diesel engine is the greater dimension, it causes trouble if the engine power is very large.
* Fuel consumption using fuel oil relatively more expensive compared to power plants that use fuels other types, such as gas and coal.

How it Works Diesel Engine

Prime mover or early mover is a device that functions produce mechanical energy required to rotate the generator rotor. In the diesel engine / diesel engine ignition occurs alone, because the process works based on pure compressed air in the cylinder at high pressure (± 30 atm), so that the temperature inside the cylinder rises. And at that time the fuel is sprayed in the cylinder-temperature and high pressure beyond the flash point fuel injected so that the fuel will burn automatically. The addition of heat or energy is always performed at a constant pressure.

Pressure of gases of combustion of fuel and air will push the piston which is connected to the crankshaft using a piston rod, so that the piston can move back and forth (reciprocating). Back and forth motion of the piston is converted into rotational motion by crank shaft (crank shaft). And contrary motion of the crankshaft rotational motion is also converted into alternating piston on the compression stroke.

Based on analyzing how the system works, diesel motors can be divided into two, namely diesel motors that use airless injection system (solid injection) were analyzed with a dual cycle and diesel motor that uses a water injection system is analyzed with the diesel cycle (while motor gasoline was analyzed by
otto cycle).

The difference between diesel and motor gasoline motor is noticeable is located on the fuel combustion process, the combustion of gasoline motor fuel is due to the fire jumps the electricity generated by two-electrode spark plug (spark plug), while the diesel engine combustion occurs due to a rise in temperature the mixture air and fuel due to compression of the piston until it reaches the flame temperature. Because the principle of pressure due to ignition of the fuel then the motor is also called a compression ignition diesel engine while the motor is called spark ignition gasoline engine.

In diesel engines, piston perform two short steps towards the cylinder head on every step of the power.
1. The first step upwards a step entry and exploitation, here the air and fuel into the crank shaft while spinning down.
2. The second step is a compression step, continue rotating the crankshaft causes the piston to rise and push the fuel, causing combustion. Both of these processes (1 and 2) including the combustion process.
3. The third step is a step expansion and work, here the two suction valves and exhaust valves are closed while the crankshaft continues to rotate and retract the piston downward.
4. The fourth step is the removal step, here the exhaust valve opens and causes the gas due to combustion of residual waste out. Gas can be due out in the fourth process is moving up the piston back up and cause the gas to exit. These two latter processes (3 and 4) including the disposal process.
5. After the fourth process, then the next process will repeat the first process, where air and fuel re-entry.

Based on the above process then the speed diesel engines can be classified into 3 parts, namely:
1. Low-speed diesel (<400 rpm) 2. Medium speed diesel (400 - 1000 rpm) 3. High speed diesel (> 1000 rpm)

Starting the system or process to turn on / run diesel engines are divided into three kinds of starting the system, namely:

1. Start System Manual
The system is used to start diesel engine with a relatively small engine power is <30 PK. The way to revive a diesel engine on this system is to use the drive crank start on the crankshaft or connecting shaft to be moved by human power. So start the system is highly dependent on human factors as the operator. 2. Electric Start System This system is used by diesel engines that have power are the <500 PK. This system uses a DC motor with power supplied by the battery / batteries 12 or 24 volts to start the diesel. At the start, the DC motor gets power supply from the battery or batteries and produces torque used to drive a diesel until it reaches a certain round. The battery or batteries used must be used to start the 6 times without recharged, since the required startup current DC motor is large enough so worn armature that serves as a DC generator. Recharging the battery or batteries used tool of a battery charger and belt tension. At the time diesel battery charger does not work then get a supply of electricity, while at work then the supply of diesel battery charger obtained from the generator. The function of the voltage security is to monitor the battery voltage or battery. Therefore, when the voltage of the battery or the battery has reached the 12/24 volts, which is the default voltage, then the relationship between the battery charger to the battery or batteries will be disconnected by a safety voltage. 3. Start the system Compression Start system is used by the diesel that has a great power that is> 500 PK. These systems use motors with high-pressure air to the start of the diesel engine. How it works is by storing a bottle of air into the air. Then the air is compressed so that the hot air and diesel fuel is inserted into the Fuel Injection Pump and sprayed through a nozzle at high pressure. The result will occur foggy and combustion in the combustion chamber. At the time the pressure in the tube down to the minimum limit, then the compressor will automatically raise the air pressure inside the tube until the pressure in the tube sufficient and ready for use to perform starting diesel engines.
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Minggu, 13 November 2011

power for energy

Model: LDR, WDR
Capacity: 8-4000kg/h
Steam pressure: 4-16bar
Fuel: Electric

Fuel: Electric
For food processing, printing and dyeing, pharmaceutical provide for production of gasoline and medical institutions with the provision of disinfection gas, for other enterprises, hotels provide the heating steam, can also provide domestic hot water heating tanks.

Electric heating boiler to power for energy, no noise, no pollution. The use of high-quality heating tubes, the surface of the low heat load, heat and high efficiency. The use of multi-storey high-level centrifugal glass wool insulation, import color outer panels; Both ends covered the use of packaging in vivo to facilitate the installation of maintenance.

1, the use of advanced electric heating tubes, the surface low load, long life.
2, the boiler to start, stop, fast, wide range of load-conditioning to regulate the speed and easy to operate.
3, heating elements in accordance with changes in temperature and automatically adjust the load control input heating group number, and automatically converted into the order, not only to save energy consumption, but also control the operation of each heating time balance, so even the life of the heating tube.
4, heating elements can also be manually input or stop, user-friendly and flexible adjustment of the boiler heat.
5, the use of advanced computer boiler controller, with reliable performance, high degree of automation is easy.
6, using boiler accessories, domestic and foreign products are selected and tested by the test furnace to ensure the long-term normal operation of the boiler.

Protection device
(A), function
1, patented technology, automatic sewage functions: On the water control system for real-time detection of ion concentration, when the concentration exceeds a set value, the solenoid valve automatically open sewage, sewage automatically, start the infusion of new water pumps, heating surface so that scaling is not easy. 2, the water level real-time monitoring function: Equipped with electronic water level detection device, real-time monitoring of boiler water level.
3, the time set function: Users can be set to stop the time from the boiler.
4, before and after outsourcing are covered in vivo, the replacement of the heating pipe maintenance operation more convenient and more efficient.
(B), the protection of
1, proprietary technology, scale detection devices: The furnace once the standard scale, the system will alarm
2, leakage protection: Control system to detect leakage electric heating elements will automatically cut off power supply.
3, water protection: When the boiler water and timely control circuits cut off the heating to prevent the occurrence of dry heating pipe damaged, dry warning issued at the same time the controller instructions.
4, power protection function abnormalities: An immediate cessation of operation of the boiler.
5, overpressure protection chain: The boiler pressure exceeds a set value, and to prohibit the heater alarm.
6, over-current protection: When the boiler overload (high voltage) work, leakage circuit breaker disconnect automatically.
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Selasa, 08 November 2011

voltage regulator diode

Zener diode is applied in the reverse breakdown of the surface contact area of the special type of silicon diode. Zener diode volt-ampere characteristic curve and silicon diode volt-ampere characteristic curves exactly the same. Zener diode characteristic curve similar to ordinary, but the reverse diode voltage curve relatively steep. Normal operating range of the diode voltage, current characteristic in the reverse current on the sudden rise in the beginning part. This section of the current, commonly used for the regulator in terms of low power, typically a few milliamperes to tens of milliamps.
The main parameters of the diode voltage regulator
(1) stable voltage Vz: stable voltage regulator diode is in normal operation, the voltage across the tube. This value with the operating current and temperature changes slightly different, both the same type of Zener diode, voltage stability has some dispersion, for example, the stability of 2CW14 silicon diode voltage regulator 6 ~ 7.5V.
(2) dissipation PM: reverse current through the PN junction diode regulator, we should have some power loss, PN junction's temperature will rise. PN junction under the permissible operating temperature determine the power dissipated in the tube. Low power tube is usually about a few hundred milliwatts to several watts.
Maximum power dissipation PZM: a regulator of the maximum power dissipation depends on the PN junction area and cooling conditions. Reverse work, PN junction power loss: PZ = VZ * IZ, and VZ by the PZM can decide IZmax.
(3) Stable current IZ, the minimum stable current IZmin, large and stable current IZmax steady current: working voltage equal to the voltage stability of the reverse current; minimum stable current: voltage regulator diode in the steady reverse current minimum required; maximum stable current: Zener diode allows the maximum reverse current.
(4) dynamic resistance rZ: the concept and the same general dynamic resistance of the diode, but the dynamic resistance of diode voltage regulator is to strike it on the reverse characteristics of the. rZ smaller, reflecting the breakdown characteristics of the regulator more steep.
rz = â–³ VZ / â–³ IZ
(5) stable voltage temperature coefficient: VZ temperature change will change in the regulator, when | VZ |> 7 V when, VZ has a positive temperature coefficient, the reverse breakdown is the avalanche breakdown.
When | VZ | <4V time, VZ has a negative temperature coefficient, the reverse is the zener breakdown.
When 4V <| VZ | <7V time, the regulator can get close to the zero temperature coefficient. This regulator diode can be used as a standard regulator.
Zener diode test
(1) positive and negative electrodes of the judge from the appearance point of view, the metal package Zener diode cathode tube-shaped end of the plane, the negative side for the semi-circular surface shape. Plastic tube regulator diode color markers printed on one end of the anode and the other end is positive. Zener diode is not clear on the signs, you can also judge the polarity with a multimeter, measure the same way with ordinary diodes, that is, R × 1k file with a multimeter, then the two table T are the two electrode voltage regulator diode, a measured results, and then swap the two table T were measured. In the two measurements, the resistance that a small, black pen then the table is the positive regulator diode, the red pen then a negative regulator diode.
If the measured voltage regulator diode, the reverse resistance are very small or are infinite, then the breakdown of the diode is open or damaged.
(2) the value of the measurement of voltage 0 ~ 30V continuously adjustable DC power supply for the 13V zener diodes below, can be transferred to the output voltage of power supply 15V, the positive power series with a 1.5kΩ current limiting resistor measured after the negative regulator diode connected to the power negative and positive phase voltage regulator diode, then both ends of the multimeter to measure voltage regulator diode, the measured reading is the voltage regulator diode value. If the regulator regulator diode is higher than 15V, the power supply should be adjusted to 20V or more.
Also be lower than the Megohmmeter 1000V diodes for testing power for the regulator. The methods were: the positive terminal of the megger negative phase with the voltage regulator diode, the negative terminal megger the positive phase with the voltage regulator diode, the required uniform shaking megger handle, while monitoring the voltage with a multimeter voltage across the diode (multimeter, as the stability of the voltage profile should be the size of the voltage) until the meter indicates the voltage stability of the instructions, this voltage is stable voltage regulator diode.
If the measurement of the stability of the diode voltage regulator fluctuated, then the instability of the diode.
Application of voltage regulator diode
Regulator used in the rectifier filter circuit, the DC output voltage to stabilize the small power supply devices.
Selection of regulator diode
Zener diode is generally used in power supply as a reference or used in over-voltage protection circuit for protection diodes.
Zener diode selected should meet the application requirements of the main parameters of the circuit. The stability of the voltage regulator diode and application should be the same value as the reference voltage circuit, the maximum stable current regulator diode application circuit should be higher than the maximum load current 50%.
Substitution regulator diode
Zener diode is damaged, should be regulated the same model the same electrical parameters of diodes or Zener diodes to be replaced.
Stability can be used with the same high-voltage power dissipation zener diodes to substitution of low power dissipation zener diodes, but not with lower power dissipation zener diodes to substitution of high power dissipation zener diodes. For example, 0.5W, 6.2V zener diodes can be 1W, 6.2V voltage regulator diode replacement.
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Senin, 07 November 2011

PIC microcontroller

PIC microcontroller provides a different combination of features, thus the most suitable can be selected for any given application. Some of the main selection criteria are:

•number of I/O pins availbale
•program memory size
•program memory type (ROM, EPROM, Flash)
•EEPROM data memory
•timers (8-bit or 16-bit), CCP
•interrupt sources
•analog inputs (8-bit or 10-bit)
•serial communication interfaces (USART, SPI, I2C, CAN)
•internal oscillator
•in-circuit debugging
•package (DIP, SOIC, PLCC, QFP)

When developing an embedded system, the number and type of inputs and outputs need to be determined. After the hardware requirements have been established, the program need to be written and tested. Once the size of the program known, the chip memory size can be determined.
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Minggu, 06 November 2011

Gel permeation chromatography

Gel permeation chromatography (GPC) involves steric separation of a sample, i.e., separation on the basis of size. Different detectors are used to analyze the resulting size fractions in order to quantify molecular weight and distribution, molecular size, and intrinsic viscosity. UV detection is used routinely to identify chemically different species as they elute. This is especially valuable for the analysis of copolymers and in the development of smart materials, since unique electrical, thermal, or photochromic properties often correlate directly with UV absorption characteristics. The difference in absorption profiles between polymers with similar molecular weights, refractive index increments, viscosities, or hydrodynamic radii can be significant; thus a UV detector can often differentiate when others cannot. However, a conventional system measures spectra only at a single, predetermined wavelength in the UV-VIS range. This limitation is overcome with the photodiode array (PDA) detector (Figure 1) for the TDAMax instrument (Viscotek Corp., A Malvern Company, Houston, TX).

The instrument is a comprehensive GPC system with an integrated triple or tetra detector array that includes low-angle light scattering, a differential refractive index detector, and a four-capillary differential viscometer. The PDA consists of 256 diodes and simultaneously collects data at wavelengths in the range 190–500 nm. With typical measurement times in the 20–40 min range producing a very data-rich analysis, the technique is extremely productive.

The UV cell of the PDA sits in the temperature-controlled zone of the system, which operates at temperatures up to 80 °C. A fiber-optic link to the PDA and then onto the powerful OmniSEC™ software package enables the captured data to be displayed as information-rich, easy-to-interpret 3-D images that provide insight into the nature of the sample being analyzed.

The PDA measures the complete absorption spectrum of the sample eluting at every time slice of the chromatogram, giving a fingerprint of each component in the matrix. Because it captures data across the UV-VIS range, the user does not need to select the wavelength of interest before measurement. This makes it much easier to carry out more open-ended investigative analysis into a complex polymerization reaction or when examining material about which little is known.

The software package is equally important since it simplifies data manipulation and presentation while controlling the chromatography. Looking at the full absorption spectra for each “slice” makes it easy to see what components— monomers, oligomers, different polymeric species—are eluting, giving information about molecular size and structure.
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Crystal manipulation and harvesting have been done manually since the science of crystallography began. While the looping of larger crystals comes easily for some people, others never seem to get the knack. Some of the problems with manually harvesting crystals (both small and macro) include:
Crystals are being harvested at earlier and earlier points in their growth cycle, sometimes when they are as small as 2–5 μm. As the crystals get smaller, the ability to manually harvest them becomes more difficult.
Manual harvesting may damage the crystals due to the user’s inability to precisely control the looping tools.
When harvesting manually, higher levels of magnification required for small crystals are difficult to use because the user’s hand motions (i.e., shaking) are intensified, distorting vision and thereby affecting the ability to accurately harvest.
It is difficult to choose a specific crystal to loop since manual looping disturbs the entire drop and any other crystals that are present in that drop
Manual harvesting of crystals is done with one loop; the use of two loops simultaneously to capture crystals is rarely done by hand.

Typically, the user places a coverslip or another vessel containing the crystals under the microscope. Because time is usually limited (especially in the case of protein crystals), the user presses a single key, and the system positions the loop(s), crystals, and microscope in preparation for harvesting crystals. (Note: Sometimes a small amount of Paratone-N oil [HamptonResearch, Aliso Viejo, CA] is used to delay the dehydration of the drop holding the crystals to allow more time for harvesting.)

If the user has already selected the crystal to harvest, he/she can choose that crystal by clicking on it with the mouse. Once the desired crystal is selected, the user can harvest it manually or invoke a macro, which will harvest it automatically based on methods and training established by the user. Although several off-the-shelf macros for crystal harvesting are included with the system, the user can program in his/her own style of harvesting, with the system mimicking the user’s every move. The programmable macros control all devices available in the automated system (XYZ stage, micromanipulators, zoom, focus, etc.), as well as all software functions such as image analysis, image capture, video capture, and Z-stacked imaging.

Because the Harvester-3D can be operated remotely, it is well suited for harvesting oxygen-sensitive crystals within a glove box and offers various other benefits when used in an oxygen-free environment. For example, with its precise joystick operation, users do not have to work with gloved hands, which is a tedious, tiring, and time-consuming method of harvesting crystals.

The micromanipulators can hold either traditional loops (MiTeGen) or other types of harvesting devices, such as the Crystal Catcher. The Crystal Catcher can be programmed to automatically harvest both protein and small-molecule crystals using its polymer-based adhesive technology, and the penlike device mounts easily onto the micromanipulators.

A typical macro for harvesting crystals is as follows:
Step 1—Move stage to harvesting position. This brings the XYZ stage into position, autofocuses the microscope, and moves the micromanipulators with loops into position.
Step 2—Mark crystal(s) for harvesting. This highlights all of the crystals to be harvested (either automatically or manually).
Step 3—Begin harvesting. Depending on whether small- or macromolecule crystals are being harvested, the procedure is slightly different. For the purposes of this discussion, we will assume small-molecule harvesting is being done using UV-curable glue to attach the crystals to the mounts.

In turn, the system will:

a) Move to the UV glue position

b) Pick up a small amount of UV glue (amount predetermined by the user)

c) Move to the first crystal to be harvested

d) Pick up the first crystal using XYZ coordinates generated when the user marked the crystal (step 2)

e) Move to UV curing light for 20+ sec to harden the glue. The user can move the micromanipulator to neutral position and pause so that he or she (or the automated arm [i.e., Hitachi, Tokyo, Japan]) can remove the harvested crystal and replace the holder for the next crystal to be harvested.
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Rabu, 02 November 2011

bridge rectifier

There are basically two versions of the P3a: a 60W into 8 ohms (with ± 35V supply rails) and a 100W into 8 ohms (with ± 42V supply rails). I decided to build the version ± 35V, for two reasons. A 60W, which is more than enough. The other is that the version is ± 42V can not drive 4 ohm speakers. I wanted the option of driving 4 ohm speakers, so the choice was easy. A ± 35V, it can be 60W at 8 ohms and 100W into 4 ohms drive.
2.2. Transistors

The transistors recommended are not available here, so I went for one of the previous recommendations. For the output transistors, I used MJ15003 and MJ15004. Used for the three drivers that I have is two BD140 (a class-A driver and an output driver) and BD139 (the other output driver).

The power supply consists of a 625 VA 25-0-25 transformer, a bridge rectifier 35A and 4 x 10,000 uF capacitors. This seems excessive, and may for all practical purposes, but which is theoretically necessary to four 100W (4 ohms) amplifier lead to an efficiency of about 70%.

The power supply requires heavy use of a starter, for which I used P39 Rod Elliott. I chose the ballast resistors so that their maximum current is used up to 200% of the transformer. In this way, the main fuse will blow, even if there is anything wrong with the transformer. Also, I attached a thermal fuse, resistors on a piece of aluminum and epoxy resin heat for added security.

As always, an amplifier is not complete without a DC protection, and I have included Rod Elliott P33 for that. See my article DC protector subwoofer for more information on this particular circuit.

I am very satisfied with the performance. But I think to do, amplifier does not affect the sound quality through a lot (as they are a decent design), and therefore I must not expect much difference with my previous (what receiver Kenwood 1978 ). Aspects that are the most visible things such as noise and the level of snoring, which are very good. There is a very very very slight hum in the speakers, but you have to press your ear against the speaker to hear it. There, I found this part of the inherent hum P3a is design, so there’s not much I can do about it, both in regard to the wiring or the power supply configuration. But because it is so marginal, it does not matter. At the end of the amplifier is exactly what I needed to, and performs accordingly.
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