Modelling of Dynamic Behavior of a Weak Power Grid?

The power systems analysis software packages I have used allow two ways to model the electricity supply to your network.As a "utility element" or "grid element" - a voltage source behind a Thevenin equivalent impedance. This is assumed to be a "large" grid with infinite inertia. As a generator element, with specified electrical parameters like rated kVA, direct/quadrature-axis subtransient, transient and steady-state reactances.The impedances are enough for basic load-flow/short circuit calculations. For dynamic/transient studies, the mechanical parameters such as moment of inertia, AVR/exciter control system, governor model, must also be specified. As you have described it, Paladin DesignBase appears to use some strange hybrid of these approaches. It's not quite an "ideal utility element" (voltage behind a source), nor is it a detailed generator element with full electrical, mechanical, and control modelling.At a guess, the correct answer to what you actually want to do, "can I start a large motor on this weak grid?", depends on the particulars of your supply. Is the grid "weak" in the sense of being run from a local generator set?I.e. the site is being run off a portable generator-set. If this is the case, then the motor starting capability of the generator-set will be published on the alternator's data sheet. Usually this is expressed as a 'Motor starting kVA'. See below example from Stamford (Cummins) PE734C datasheet.Is the grid "weak" in the sense of being connected to the national power grid, but at the end of a very long and skinny transmission line?That is, the inertia of the system is practically infinite, but the short-circuit capacity is low due to the high impedance of the feeder line. If this is the case, the motor starting time is irrelevant so long as you meet any technical rules imposed on you by the distribution network operator. In Australia this is usually a limit on voltage dip.In both cases, the motor starting will only succeed if the motor terminal voltage is high enough to produce sufficient starting torque. If the motor terminal voltage is above 80% at motor starting, you are probably OK. If the motor terminal voltage is less than 70% at the max inrush current, there's a good chance your motor will stall. This would warrant closer examination of the motor torque/speed curve, load torque/speed curve, and motor thermal withstand curves. Remember that torque is proportional to the square of voltage, so 70% voltage = 50% torque, and that excessively long start times may cause overheating of the motor windings.The correct answer to the question as asked, "how do I model a weak grid?", is to fully model the generator(s). That means you need to model:This information is only published for reasonably large units, i. e. 40MW aeroderivative gas turbine generators. For small portable generator-sets (1MW) you are expected to use the "motor starting kVA" data in the datasheet

1. Motors | How to Choose an Electric Motor

How to Choose an Electric Motor electric motor converts electrical energy into mechanical energy. This is achieved by the principle of electromagnetic induction. Electromagnetic induction is the principle that a current carrying conductor, when placed in a magnetic field will have a force exerted on the conductor proportional to the current flowing and the strength of the magnetic field. The basic principles of electromagnetic induction were discovered in the early 1800's by Oersted, Gauss and Faraday. However, it was Tesla who was able to take motor technology to the next level in the late 1800's and revamped the manufacture of motors as well. Tesla was able to successfully garner 900 patents in the electrical field that had relevance for motor applications. The working parts of a basic electric motor include: Note: Please note that the larger number of field coils used the smoother the motor will run. Simply put, anconverts electrical energy into mechanical energy. This is achieved by the principle of electromagnetic induction. Electromagnetic induction is the principle that a current carrying conductor, when placed in a magnetic field will have a force exerted on the conductor proportional to the current flowing and the strength of the magnetic field. The basic principles of electromagnetic induction were discovered in the early 1800's by Oersted, Gauss and Faraday. However, it was Tesla who was able to take motor technology to the next level in the late 1800's and revamped the manufacture of motors as well. Tesla was able to successfully garner 900 patents in the electrical field that had relevance for motor applications.The working parts of a basic electric motor include: There are various types of AC Motors, including single-phase and poly-phase. Poly-phase motors have phase winding groups that are placed in conjunction with the phase sequence of the power supply line. This produces a rotating field around the rotor surface. Single phase electric motors do not produce a rotating field at a standstill, so a starter winding is added to give the effect of a ply-phase rotating field. Once the motor starts, the winding be eliminated from the circuit and the electric motor will continue to run on a rotating field that now exists due to the motion of the rotor interacting with the single phase stator magnetic field. There are various types of AC Motors, including single-phase and poly-phase. Poly-phase motors have phase winding groups that are placed in conjunction with the phase sequence of the power supply line. This produces a rotating field around the rotor surface. Single phase electric motors do not produce a rotating field at a standstill, so a starter winding is added to give the effect of a ply-phase rotating field. Once the motor starts, the winding be eliminated from the circuit and the electric motor will continue to run on a rotating field that now exists due to the motion of the rotor interacting with the single phase stator magnetic field. DC Motors are ideal for converting direct current or electricity into mechanical energy. The advantages of a DC Electric Motor are: Speed Variation and Torque. Speed of the DC Motor can be controlled by varying the amount of current to the motor. And the turning power, or torque, of the DC Motor can be controlled by varying the amount of power coming from the power supply. DC Motors are ideal for converting direct current or electricity into mechanical energy. The advantages of a DC Electric Motor are: Speed Variation and Torque. Speed of the DC Motor can be controlled by varying the amount of current to the motor. And the turning power, or torque, of the DC Motor can be controlled by varying the amount of power coming from the power supply. There are many varieties of fan motors. Fan motors are electric motors that allow fans to run regularly over a long period of time. The type of fan motor necessary depends on its application. Single-Phase Fan Motor - Single-Phase motors are the most common electric fan motors, as they connect with most smaller sized fans and operate on existing (AC) power sources. Each cycle dips and tops as electrical power increases, making it an electric motor which runs off a reduced amount of electrical power. This process is low-cost and puts little pressure on the electric motor's mechanical functions. Single-Phase Electric Motor - Split-phase motors are used for big commercial fans, or fans in larger devices which run off of a medium amount of electricity. These motors have start and run windings, both of which are stimulated when the motor is activated. Split-Phase Electric motors have built-in safety features that allow them to automatically shut off to prevent burn-out. There are many varieties of fan motors. Fan motors are electric motors that allow fans to run regularly over a long period of time. The type of fan motor necessary depends on its application. A Servo Motor allows for precise control of position. Feedback and angle of the motor is controlled via a control box in this type of motor. Servo Motor applications include laser cutting machines, robotics, CNC machinery or automated manufacturing. A Servo Motor allows for precise control of position. Feedback and angle of the motor is controlled via a control box in this type of motor. Servo Motor applications include laser cutting machines, robotics, CNC machinery or automated manufacturing. How to Choose an Electric Motor When you are attempting to choose the perfect motor, the following should always be considered: Cross reference the manufacturer's part or model number from the motor itself. This information is usually on the nameplate of the motor. If this information is not readily available, attempt to match the electrical specifications and physical dimensions of the defective motor. The following questions should act as a guide through the electric motor selection process: What are the electrical specs? - (typically found on the nameplate of the motor) What speeds do I need? Phase (1 or 3), in the case of appliance or industrial applications What are the physical dimensions? Length and Diameter of the Electric Motor, and Length and Diameter of the Shaft How should I mount this Motor? What is the mounting style of the Electric Motor? (rigid base, belly band, thru-bolts, cradle base, etc...) What type of Enclosure do I need? Is the Electric Motor open drip-proof (ODP), totally enclosed air over (TEAO), totally enclosed fan cooled (TEFC)? Motor application (to what is it attached?) When you are attempting to choose the perfect motor, the following should always be considered:The following questions should act as a guide through the electric motor selection process: This electric motor diagram shows a typical four-pole DC Motor, assembled and disassembled. The electric motor diagram also depicts the windings, commutator, field poles and shaft of the DC Motor. This electric motor diagram shows a typical four-pole DC Motor, assembled and disassembled. The electric motor diagram also depicts the windings, commutator, field poles and shaft of the DC Motor.

2. My truck will shake and both my front wheels are very hot and I smell burning but only sometimes?

Any light lit up on the dash? Any fault code in the ABS? (Anti lock brake system). You will need to go back to your mechanic and ask him to check the "Hydraulic Brake Pressure Balance Control System" for defect. In short: The system regulates brake fluid pressure delivered to hydraulic brake wheel circuits, in order to control the distribution of braking force between the front wheels and rear wheels. Pressure balance control is achieved through Dynamic Rear Proportioning (DRP), which is a function of the ABS modulator. In simple term: It's the ABS pump (Hydraulic unit) A little into detail: Brake pressure modulator valve (BPMV) - The BPMV uses a 3-circuit configuration to control the left front wheel, the right front wheel, and the combined rear wheels. The BPMV directs fluid to the left front and right front wheels independently. The BPMV directs fluid to the two rear wheels on a single hydraulic circuit. The BPMV contains the following components: Pump motor. Three isolation valves. Three dump valves. A front low-pressure accumulator. A rear low-pressure accumulator. A complete diagnosing of the system is required to pinpoint the cause on the ABS system. A scanner is the first requirement tool need to have. If he does not know what I am talking about then go for a second opinion.. Anymore question?:

3. Fishing:Would you ever do this to your license plate?

There are lots of them,like " IF I GO FISHING ONE MORE TIME,MY WIFE SAYS SHE"LL LEAVE ME...GOSH I'M GONNA MISS HER!! Or the one WANTED: good woman,able to cook clean sew and cut bait,clean fish and run boat,must have boat and motor,send picture of boat and motor teeth not a requirement,but desired to have a couple....There are loads of them and some are quite funny. Hey,where he's from an 8lber is not so small,mine was over 25 years old.Up here in the north,they do not grow that fast.The state record is 15 lbs

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I Bought a Motorbike (TVS) Recently and Observed That the Engine Heats Up a Lot. Is It Because the B
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The Oldest Womens Motorcycle Club Is Strictly Feminine and also Badass
Dot Robinson soldiered through 500 miles of endurance tests. She forded rivers, waded through sand, scrambled up rutted mountainsides — all on a motorcycle. By the end of two days, she became the first woman to win the Jack Pine National Endurance Championship, which in 1940, was the two-wheeled equivalent of Daytona. Robinson dedicated her life to the sport, and would become known as the "First Lady of Motorcycling." But first, she was a Motor Maid.The same year she won Jack Pine, Robinson met another young bike enthusiast. Linda Dugeau wanted to start a motorcycle organization for women, inspired by The Ninety-Nines, Amelia Earhart's troop of female pilots. The pair set about recruiting for their new venture, the Motor Maids of America.The going was rough at first. The few women riders they did find were either outcasts or afraid to be seen as such. The prevailing assumption was that all women bikers were lesbian man-haters. And making solo trips around the country was downright dangerous, stereotype or not.For the founders, these fears would form the backbone of their mission. Beyond a social club, the Motor Maids would act as ambassadors for the sport, and offer a legitimate, organized, safe space for women to get more involved. In the first year, the group managed to secure 51 members from around the country.The original approach was cliche. As president, Robinson instituted a Motor Maid uniform policy: pink, with white gloves.During the first four years, the club grew slowly. Wartime gas rationing made it nearly impossible to hold meet-ups. But thanks to Robinson's reputation, the Motor Maids earned the support of Arthur Davidson, a founder of Harley-Davidson. The endorsement helped legitimize their pursuit. (Meanwhile, Robinson and her husband, Earl, operated a Harley dealership in Detroit.)On May 27 and 28, 1944, the Motor Maids met for their first convention in Columbia, Ohio. 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What Is the Best Starter Cruiser Motorcycle?
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Hooking Up a Desk-top Pc in a Motor Home, Is It Possible?
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Maximum Value of Back Emf in Dc Motor?
The back EMF is proportional to speed. As the load increases, the speed will decrease. That will cause the back EMF to decrease. Note that there is a voltage drop across the armature resistance. That voltage drop plus the back EMF is equal to the supply voltage1. DC motor speed is too low while interfacing with L293D motor driver and ATmega8Here's what the L293D spec says: -In red I've extrapolated what this means for a 6V battery supply. So, in a H bridge you can not really expect to put more than 3 or 4 volts onto your motor from a 6V supply. The device is not modern and it is not geared up for driving 6V motors from a 6V supply. Also note the current drive capability of the device is 0.6A which is poor for driving any decent mechanical load2. If carbon is non-metal, then how do carbon brushes in a DC motor transmit electric current?Actually carbon brushes of DC motor are made from a weak conductor of electricity, called graphite. It is an allotrope of carbon. This material has a smooth planar lattice arrangement and has a lot of "valence" electrons or free electrons in the lattice. These electrons can move when an electric potential is applied to the sides of a graphite plate.3. How can I obtain the torque of DC motor knowing that I have the voltage signal?If it has a nameplate, find the part as listed by a distributor. Look over the specs supplied by the distributor4. What is the difference between 24v-20 Amps DC motor and 230v -2 amps DC motor?When you connect load to the generator, the motor needs more Torque to drive the generator shaft.... For a DC motor, the torque generated is directly proportional to the current taken & Inversely proportional to speed ----------->Thats why the second motor is able to drive the the generator.5. DC Motor's don't stop immediatelyWhile I totally agree with the other answers on the issue of using a non-blocking timer, I would like to add another factor about motor braking from a purely "electrical" point of view.......To "brake" a running DC motor, you need to short the two terminals. This will generate a back current in the coil which will reverse the magnetic field and stop the motor much faster than by just cutting off power to the terminals. This is not possible to implement using a Bi-polar H bridge motor driver like L293D. You need to use a MOSFET type H-bridge6. Can you use an AC switch with a DC motor?Hi, . . . Usually NO.. . For low voltages 12V DC should be OK, even 24V might be OK, if it is a big switch.. . But depends on the switch design and how it physically works. . . But generally NO7. Pull away voltage (energy) from a DC motor driver board when it does regenerative brakingThe obvious solution is a clamp that conducts if the voltage tries to go above 50 V. Something like this:-simulate this circuit - Schematic created using CircuitLabYou can not do that because the voltage at that point is a mains frequency sine wave going from 0 V to 50 V. To feed power back into the transformer you would have to convert the DC voltage into AC with the correct voltage and phase.8. Does operating a DC motor at low PWM freq (500 Hz and below) deteriorate the motor performance?there is no rule that applies to all motors, but in general if the frequency is high enough the inductance of it becomes more relevant and it tends to heat up more easily. An advantage is that most humans cannot hear those frequencies so it would make less sound that you can hear at least. Increased heat can damage winding and other parts easily so you can have that in mind. At low frequencies, the ripple of the current is more pronounced, this makes the motor less efficient in general, but I doubt it causes any issues due to stress or anything else, it just runs less efficiently if the frequency is too low9. Current limiter for small 12V DC motorSorry it is now past 1 AM here and I am getting tired. I just wanted to give you a heads-up what the idea was. The bridge rectifier makes sure that the current through the circuit always goes the same way, no matter which way the motor turns. simulate this circuit - Schematic created using CircuitLab
The Brushless Motor of Coffee Machine Can Solve the Difficulties of Traditional Motor
With the increase of consumers' demand for products, there are more and more cases that the motor used in the original coffee machine water pump is changed from induction motor to brushless motor.The following is a brushless motor used on the water pump of the coffee machine. The specific parameters of the brushless motor of the coffee machine: the outer diameter of the motor is 60mm, 2200v, input power: 50W, output power: 400W, torque: 4.4kg-cm, no-load speed: 6000rpm, load speed: 400rpm, efficiency 88%, protection grade IP54. The parameters can be customized as required in terms of performance.The brushless motor of coffee machine solves the difficulties of traditional motor. The DC brushless motor can be adjusted and controlled conveniently and quickly by using the control board, and the DC brushless motor has high efficiency and long service life, which is closely combined with the core value of low-carbon and environmental protection.The motor must have a large starting torque, which usually exceeds the rated torque of the motor design. The general method to improve the motor torque is to increase the motor phase voltage. Limited by the basic electrical parameters of the electronic devices of the main power switch of the control board, the DC brushless motor can not be started with a large total electrical flow. The difficulty of heavy load is an important difficulty encountered in the application of DC brushless motor in the mixing device, Solving this problem is the key to the flexible application of Brushless DC motor in mixing device.As the future development direction, brushless motor of automatic coffee machine has been widely used in various fields at this stage. With the improvement of consumers' requirements for products, many high attention points will be put on material selection and service life. Brushless DC motor has some advantages over traditional motors and is superior to traditional motors.fqj
Design of DC Motor Speed Regulation with PIC16F874 Single Chip Microcomputer As the Central Processo
In modern industrial production, motor is the main driving equipment. At present, KZ-D driving system with thyristor (i.e. silicon controlled) device to supply power to motor has been widely used in DC motor driving system, replacing the bulky F-D system of power generation motor. With the high development of electronic technology, DC motor speed regulation has gradually changed from analog to digital, In particular, the application of single chip microcomputer technology makes the DC motor speed regulation technology enter a new stage. Intelligence and high reliability have become its development trend. The speed regulation system uses PIC16F874 single chip microcomputer as the central processor and makes full use of the characteristics of PIC16F874 single chip microcomputer capture, comparison and a / D conversion module as the trigger circuit. Its advantages are: simple structure, synchronous with the main circuit, stable phase shift, sufficient phase shift range, control angle adjustment up to 10000 steps, and stepless and smooth control of the motor, The pulse front is steep and has sufficient amplitude, the pulse width can be set, and the stability and anti-interference performance are good.1. Speed regulation principle of DC motorThe relationship between the speed n of DC motor and other parameters can be expressed by the following formula:(1)(1) Where: VA - armature voltage, IA - armature current, ra - total resistance of armature circuit, CA - potential constant, Φ - Excitation flux.(2)(2) Where: P-number of poles, n-number of conductors, A-number of armature branches.Ca Φ= K (3)(3) Where: when the motor model is determined, CA Φ Constant, so equation (1) is changed toIn medium and small power DC motors, the armature circuit resistance is very small, and the IARA term in equation (4) can be omitted. Therefore, when the armature voltage is changed, the speed n will change.2 system working principleThe system is mainly composed of main control switch, motor excitation circuit, thyristor speed regulating circuit (including speed measuring circuit), rectifier filter circuit, smoothing reactor and discharge circuit, energy consumption braking circuit. The system is controlled by closed-loop PI regulator. When the main control switch is closed, the single-phase AC is controlled by the thyristor speed regulating circuit, and then through the bridge rectifier, filter and smoothing reactor to obtain small pulse and continuous DC, which is supplied to the motor. At the same time, the AC is rectified by the excitation circuit to excite the motor and start working. Adjust the speed setting potentiometer RP1 in the trigger circuit, so that when the input voltage of an1 decreases, the control angle output by PIC16F874 single chip microcomputer decreases accordingly, the thyristor conduction angle increases, the output voltage of the main circuit increases, the motor speed increases, and the output voltage of the speed measuring circuit also increases. After the action of PI regulator, the motor operates stably within the set speed range.3 circuit design of each part of the system3.1 main circuit designThe parameters of each element in the main circuit are shown in Figure 1:Press the start button SB1, the contactor km coil is energized, the KM normally open contact is closed, the normally closed contact is open, the start button is self-locking, and the main circuit is connected. The thyristor speed regulating circuit controls the AC output by changing the control angle of the bidirectional thyristor, and then obtains the DC after bridge rectification and filtering. At the same time, the motor obtains the excitation after rectification through the excitation circuit and starts to work.Press the stop button SB2, the contactor km coil is powered off, the KM normally open contact is opened, the normally closed contact is closed, the self-locking is released, the main circuit is powered off, and the motor stops working.In order to limit the DC current pulsation, the smoothing reactor is connected in the circuit, and the resistance provides a discharge circuit for the smoothing reactor in case of sudden power failure of the main circuit.In order to speed up braking and parking, energy consumption braking is adopted in the device, and the braking link is composed of resistance R4 and normally closed contact of main circuit contactor. The excitation of the motor is powered by a separate rectifier circuit. In order to prevent the runaway accident caused by the loss of excitation of the motor, the under current relay KA is connected in series in the excitation circuit. The action current can be adjusted by potentiometer RP.3.2 thyristor trigger circuit designThe thyristor trigger circuit and parameters are shown in Figure 2. The voltage from point a and B in the main circuit is transformed to - 20 V through the transformer, and then after bridge rectification, a half wave signal of about 100 Hz is generated at point 2. After dividing the voltage through R6 and R7, it is connected to the NPN triode for amplification. A zero crossing pulse is generated at the triode collector, and the rising edge of the zero crossing pulse is captured by the Ccp1 module, Record the occurrence time, and then capture the falling edge of the zero crossing pulse. The time difference between the two is the zero crossing pulse width, and half of its value is the pulse midpoint. Using this capture method, the actual zero crossing of AC can be accurately obtained. At the same time, the ADC analog-to-analog conversion module is used to convert the value of ra1 / an1 analog voltage of PIC16F874 pin as the set value of thyristor control angle (motor speed setpoint) At the same time, the output value of the speed measuring circuit is input by the PIC16F874 pin rc0 / t1cki and counted by the tmr1 counter to calculate the speed as the speed feedback value. The oscillation frequency of the single chip microcomputer in this system is 4 MHz. According to the characteristics of the command cycle of the PIC16F874 single chip microcomputer, the resolution of the thyristor control angle is that of the single chip microcomputer The reciprocal of one quarter of the swing frequency, i.e. 1US, for the half wave time of power frequency power for 10 ms, the control angle can reach 10000 steps, which can fully realize the stepless smooth control of the motor.3.3 design of speed measuring circuitThe speed measuring circuit is composed of an optical code disk attached to the motor rotor and an electric pulse amplification and shaping circuit. The frequency of the electric pulse is in a fixed proportional relationship with the motor speed. The electric pulse signal output by the optical code disk is amplified and shaped into a standard stack TTL level. It is input from the PIC16F874 single chip microcomputer pin rc0 / t1cki and counted through the tmr1 counter to calculate the speed, and the speed is compared with the preset speed Through the PI operation of this difference, PIC16F874 obtains the control increment, and sends the size of the thyristor control angle in cCP2, so as to change the effective voltage added at both ends of the motor and finally achieve the purpose of controlling the speed.4 system software designThe speed closed-loop control is designed as a typical I system, i.e. PI regulator, which is used to adjust the thyristor control angle time TD. Its control algorithm is as follows:Where a1 = KP, KP - proportional coefficient of the controller, T1 - integral time constant, Ti - sampling period.The software design module of the system mainly includes Ccp1 rising edge capture module, Ccp1 lower rising edge capture module, control angle setting value a / D conversion module, speed measurement circuit pulse timing counting module, PI regulator module, cCP2 comparison output module, etc. the relationship of the program flow chart of each module is shown in Figure 3.Fig. 3 flow chart of Ccp1 and cCP2 module interrupt programSuppose we get that the zero crossing time is t σ, If the thyristor control angle time is TD, send it to cCP2 register ccpr2h: l and the comparison value TF = t σ TD, after the comparison is consistent, the high level will be output on the cCP2 pin to turn on the thyristor, and then the ccpr2h: L value will be modified again according to the required trigger pulse width value to maintain the output high-level trigger pulse for a certain time and then return to the low level, so as to complete a bidirectional thyristor trigger pulse output.5 Conclusion
Strongest DC Motor I Can Find in the 500-750 Gram Range?
There are many places to look, try a industrial /commercial motor supply company in your area , call or go in and talk to them , or look online and send an email , I think for $40 you might hit a scrap car place and get a used starter motor1. Arduino: How can one control a 2-wire DC motor with PWM?use a motor shield, which have an external power socket. I have controlled 2 motors and 2 servos with one arduino board ... seems to work just fine. plus you should probably look into providing it with more amps as arduino only provides you with 40 mA.2. Why do we need a transistor with a dc motor while we don't need one with a servo motor?Because a servo contains a driver circuit that controls the motor portion, whereas a motor does not . The transistor is the (simplistic) driver circuit for the motor3. What is the best way to power a 90v DC motor?Look at high-powered electric RC airplanes. Some of them use induction motors which they drive with a 3-phase flux vector drive (i.e. A 3-phase AC inverter). The battery packs and power output is about what you are after. The voltage is low, but it's high-frequency AC. You could set the inverter for one frequency and wind a transformer (or 3) to kick the voltage up to your motor's voltage at that frequency. Then rectify to DC and voila4. shooting object by using a DC motorTo shoot a coin, you need a fair amount of speed. A DC motor will probably accelerate too slowly to achieve the required speed in such a short distance. My advice would be to use something with less travel but more speed. A solenoid can be used punch something pretty hard. They typically travel less than an inch, but with a good current pulse, will kick pretty hard. If you do not have enough current available, then you can charge up a large capacitor, and discharge it suddenly into the solenoid. Alternatively, you can mount the coin on a spring which is held back by a little solenoid. When you energise the solenoid, it pulls back a catch which releases the spring which fires the coin. The down side is that you would have to re-set the mechanism each time. (or you could use a motor to pull the catch).Lastly, as David Kessner suggested, you could have a pair of counter-rotating flywheels. Whacking the box pushes the coin into the wheels, which grip it and throw it skyward. The downside to this is that you need to keep the power on to keep the wheels spinning, which is a bit of a waste5. What's the necessity of a starter for a dc motor?large DC motors have high initial current draws6. How to control the speed of a DC motor?No, a rheostat maybe, but hard to find one! Best plan is to make up or buy a puse width controller. Many designs on the web, it's just a matter of finding one that will suit your motor voltage and current requirements. Note that however you control the speed, it will be the load on the motor that determines final speed. If the load varies, so will the RPM.7. How many minutes can Dc motor stand in continues running?Some motors are designed for continuous duty and some are not. What kind of DC motor are you asking about? In general, DC motors are made to be run with a load. It is not good for them to run without a load because they spin faster than they can handle. The centrifugal forces tear them apart. In particular, a series-wound DC motor self destructs rather quickly without a load.8. Required Gear ratio for a DC motorThere are many contributing factors to this, most of which is related to frictional force, incline etc. If we ignore these for a momentIf we start off with $F = ma $ and equally $ T = F*r$ Where$fracT_wr = ma $ if $T_m = -6mu omega_m 0.0059 $ and thus$T_w = -6mu fracomega_wR 0. 0059 $ substituting back into $frac-6mu fracomega_wR 0.0059r = ma $ now it is stated the desired speed is 0.3m/s The circumference of the wheel is $2 pi r$ & thus $speed = omega_w r $ thus $omega_w = frac0. 3 r$ substituting into and rearranging for R:$ R = frac-6mu * 0.30.00375*(0.1*1.150*0.00375-0.0059) = 0.08777$ or rounded up... 12:1 gearbox
Will Anything Go Wrong If I Put to Much Oil in My Motorcycle?
Will anything go wrong if I put to much oil in my motorcycle?No, you do not want to add more oil to the crankcase or the gearbox than what is supposed to be in there. Check the adjustment of the clutch cable to see if that's what is wrong. it's possible that the clutch is stuck. Sometime rocking the bike back and forth with the engine off will work the clutch plates apart. Failing all that, you may have to pull the clutch cover to free up the clutch plates.— — — — — —Here in Canada we have more Oil and Wheat than we can use...why are we paying high prices?Wheat and Oil are commodities, bought and sold on a global market. Your wheat producers will sell their wheat on the open market to the highest bidder. Because wheat is scarce in other parts of the world, and because countries like China have more money, they are willing to pay more for the wheat. Thus, if the Chinese are willing to pay more for wheat, it drives the price up for everyone. This same thing happens with oil, which is why prices are high and most people do not get it. China is booming and imports 1/3 of it's oil. If they are willing to pay $120 a barrel, then the producers will sell it to the highest bidder. That means that the rest of us will have to pay $120 a barrel, too. The only way to avoid this is through State-owned oil and wheat industries, having reserves and so forth. Neither Canada nor the USA have these types of programs.— — — — — —What is the diet for a South Indian vegetarian to get a model-like body?Yeah you can eat more salads fruits and boiled vegetables along with sprouts and Beans avoid more rice take rice made up of brown rice or less polished rice if possible do eat chapati but do not use maida avoid all bakery items made up of maida everyday do practice yoga Pranayam along with little bit running exercises do not allow more sugar more salt for more oil but do take proteins carbohydrates oil preferably e Rice bran oil Karadai oil,take coconut oil groundnut oil in less quantity.Take buttermilk,milk regular,avoid coffee and if desired take English Tea with lemongrass adrak content.Meditate regularly and keep yourself to be active like Goddess Mahalaxmi MahaSarswati MahaParvati meditate more and more with devotion think of them and see you soon can shine like them at least little bit glory of those Goddesses will enter in you. What is the diet for a South Indian vegetarian to get a model-like body?— — — — — —DOES YOUR FOUNDATiON LAST ALL DAY? (10 points for help)?Sounds like you have some T-zone oiliness. I have the same problem. Use a good face wash for combination skin (I like the Clinique Take the Day Away) then an astringent for oily skin, but only on your nose and cheeks. I like plain old Sea Breeze, and the store brands of that work fine. Then, apply a good moisturizer for oily skin, I use Neutrogena Oil-Free Moisturizer SPF 15. It's cheap, and has the added benefit of an SPF. Then I use foundation. I prefer Clinique, but any brand will do as long as it's oil free and non-comedogenic. Make sure you get one that matches the shade of your skin. I follow that with powder. I use a loose, because compact powders usually have more oil. I use Clinique in that too, but a good lower priced powder is Cover Girl Fresh Look. I also keep a packet of Clean & Clear Oil Absorbing Sheets in my purse. They are awesome! Just remove one from the package and press it to problem areas. Some days it takes 3 or 4. They wick the oil away and do not mess up your makeup. I might dab on a bit more powder after, but usually that's not necessary— — — — — —Can someone help my friend?i think she might be overdoing it. your hair naturally produces oil.the more you wash it out.the more it's going to produce. same with your skin. too much make up will cause it to produce more oil. maybe she should cut down on her hair every other day.true at first it's going to be pretty gross, but eventually her scalp will stop producing so much oil because it's not being stripped of the oil it needs. as for her face maybe she should try just a light powder instead of liquid foundation. the powder will cover up the oil without "suffocating" her skin
How to Die Down Motorcycle Saddle Bags That Are a Little too Big and Move Around a Little too Much?
Go to a back-packing/sports shop, like REI. Look for the adjustable straps with quick-release plastic locks. Will need to improvise where to tie on and may need to back-up the fitting. Hard bags do have their advantages!1. Does anyone know of a small propane stove?Coleman Peak 1 stoves are available everywhere. More compact models like the MSR's are usually found in outdoor specialty stores like REI, EMS and L.L. Bean. Check Campmor's online catalog for a range of stove choices.2. i need camp stuff, can u help me? PLEASE!?Honestly, you will be a lot happier if you get your gear from someplace like REI. Target and Walmart do not sell good camping gear3. How do I get my water pipes to unfreeze in my rv?damn... Open the hose if u can, see if is the hose or the pipes. But 70 percent alcohol from walgeeens. Or any pharmacy and pour it at a point where can go towards the ice plug. Also u can buy a camper (sport autority, rei so on)heater with propane and heat them up slowly. For preventing and as another solution, buy an electric wire heater that u wrap around the pipe, they have it by lenght 20-30 bucks, will keep it warm enough. Wrap the pipe, plug it in, and check next day.4. Will it ruin anything if I watched Ga Rei zero before Ga Rei?Watch Ga Rei Zero5. How can you heat-mold ski boots at home?Rei Ski Boot Fitting6. i am going on holiday for 6 weeks to Sri Lanka in June. What should i take?! Serious answers pls.?O.K., well when I went to Sri Lanka, I went in January, and it rained quite a bit, but it was sunny and humid too. You will need to get all of your vaccinations and malaria pills from your local clinic. I would'nt worry about bringing bottled water, everywhere I went you can buy bottled water cheap from a local grocery/convenient store, if your worried about water you can buy a small travel sized water filter it is like a little pump you can get them at most travel stores and places like REI. You will have a blast! a good pair of walking shoes is essential, but flipflops are great for the hot weather, a bathing suit and a pair of sunglasses. (maybe a wind breaker that can fold up real small) remember you can also purchase anything you forget for a small price! (i dont really support the disposable society) but, if you need it, and can afford it, buy it! have an amazing time!7. Ubuntu 14.10 does not shut down on Acer Extensa 2509 notebookJust thoughts... I have equal problem with Fujitsu-Siemens AMILO Pro V3505, started at unnoticed moment of time (13.10 or 14.04). Upgrading to 14.10 did not solved the problem. Even the shutdown screen is similar to yours: after shutting down the ModemManager (do you have built-in dial-up modem?) system stuck on "Will now halt"And it is not the installed system's fault: USB-HDD with installed 14.04 behaves equally, while works just fine on other PCs. (can not remember, if there's ModemManager installed on that HDD)Preinstalled Windows XP Home (bootable via GRUB) shuts down/reboots the PC correctly. It looks like something broken in ACPI control software.When I tried REIUSB, REI all gave me "This function is disabled", while USB did what intended: emergency remount R/O, emergency sync and reboot.8. problem keeping fingers tips warm under motor cycle gloves?I have had people try and explain why, but a pair of lined or unlined windproof fabric snow mittens that keeps your 4 or 2 & 2 fingers together with a separate thumb works better than any gloves I have ever tried, except electrics. I have a nice pair I bought at REI that came with a removable liner and have used them down to 29 degrees for 60 mile ride. Some even have pockets outside for dropping those disposable hand warmers into.9. whats everything i need to buy for snowboarding?Well: a snowboard, snowboarding boots warm clothes like ski pants and a water proof jacket helmet if you want, but I would advise one! money to buy your lift ticket SNOW!! LOL I am not really sure where to buy this stuff cheap... Ummm I would try second hand stores, or maybe e-bay. You could always buy this stuff at REI, or Northface but these are more expensive. You can also rent the snowboard and boots at the ski place. If you are just going once of twice this year that will be cheaper than buying the stuff secondhand. Hope I helped! :)
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