What is Collector: Definition and 69 Discussions

Electric current collectors are used by trolleybuses, trams, electric locomotives or EMUs to carry electrical power from overhead lines or electrical third rails to the electrical equipment of the vehicles. Those for overhead wires are roof-mounted devices, those for third rails are mounted on the bogies. Current collectors are also electric bridging components that collect electrical current generated at the electrodes of electrochemical devices, such as lithium-class battery cells, and connect with external circuits.
Typically, they have one or more spring-loaded arms that press a collector or contact shoe against the rail or overhead wire. As the vehicle moves, the contact shoe slides along the wire or rail to draw the electricity needed to run the vehicle's motor.
The current collector arms are electrically conductive but mounted insulated on the vehicle's roof, side or base. An insulated cable connects the collector with the switch, transformer or motor. The steel rails of the tracks act as the electrical return.
Electric vehicles that collect their current from an overhead line system use different forms of one- or two-arm pantograph collectors, bow collectors or trolley poles. The current collection device presses against the underside of the lowest wire of an overhead line system, which is called a contact wire.
Most overhead supply systems are either DC or single phase AC, using a single wire with return through the grounded running rails. Three phase AC systems use a pair of overhead wires, and paired trolley poles.

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  1. Salah

    Chosing air blowers to force air through a solar heat storage array

    hi guys: i plan to make solar collector using rectangular hollow steel bar 4×8cm filled with gravel as heat storage and blow air through it and direct that air as preheated for gas combustion oven to reduce gas consumption .can i use a normal fan or it has to a blower?
  2. Salah

    A Clear night sky radiative cooling -- How to optimize?

    hi guys: what should be the colour of the collector for best cooling effect of night clear sky radiative cooling?
  3. seanduffy

    I Pool Solar Heating - Help orienting the roof-top solar collector please

    Hello there, Physics forum. I live in Alamo, California and I'm planning to install pool solar. All of the installers have completely different POVs on which face of the roof I should put them, and hoping to get some physics-based advice. Here's the home with the 3 face options (front already...
  4. Helena Wells

    BJT common collector Colpitts oscillator

    This is a BJT common collector colpitts oscillator.I have found how to find the feedback fraction from this site:http://fourier.eng.hmc.edu/e84/lectures/ch4/node12.html but I have searched for hours and haven't found the amplifier gain of this circuit. I have found the amplifier gain for...
  5. Helena Wells

    Understanding BJT Common Collector Circuit: Voltage and Saturation Explanation

    Assume we have a common collector circuit with a emitter resistance of 1k Ohms.Vc = 10V Ve is connected to ground. Now we connect the base of the transistor to 5V . The base current will be 5-VBE/1000 Amp.Let's say a voltage drop of 0.7 in the BE junction .We will get Ib = 4.3mA. Ic = bxIb =...
  6. R

    Can cell electrodes in series share the same current collector?

    Sorry if the answer is obvious, but I was wondering if positive and negative electrodes (cells in series) can share the same current collector as depicted below? I want to create a 12V battery with cells inline in series without creating cells with individual current collectors. Note that the...
  7. F

    BJT Transistor Collector Current

    I’ve attached an image below of a section from my textbook and some circuit simulations. The textbook gives an equation for the collector current in a bjt transistor. The simulation shows two circuits (with the same bjt transistor) that hav equal values for all variables present in the textbook...
  8. Y

    Looking for a BJT with low collector leakage current

    I am looking for small signal BJT that has very low leakage current when the base is biased at about 0.2V. I have issue of transistors drawing collector current when the base is at about 0.25V that is way less than the normal turn on of 0.6V to 0.7V. I am currently using BC546 or 556, and KSA992...
  9. C

    Electrical Miniature Turbines for a solar collector

    I have a satellite dish converted to a solar collector. It isn't very big, just a small scale prototype at the moment. I have measured just over 300 degrees Celsius at the focus point. I am considering either using a sterling engine or a steam turbine to generate some electricity. The problem...
  10. Y

    Calculate collector current of phototransistor

    Hello, I'm wondering if it is possible to calculate current the collector current of a phototransistor that is paired with an IR Led? I have an IR Led that is 13.6 cm away from the phototransistor and has a radiant intensity of between 65 mw/sr and 125 mw/sr. The phototransistor that I'm...
  11. G

    What is the equilibrium temperature of a collector plate?

    Homework Statement You would like to put a solar hot water system on your roof, but you're not sure it's feasible. A reference book on solar energy shows that the ground-level solar intensity in your city is 750 W/m^2 for at least 5 hours a day throughout most of the year. Assuming that a...
  12. nothing909

    How does an open collector work?

    I'm slightly confused as to how an open collector works. When a logic low input, the NOT gate is high, turning on the transistor and allows the current to flow from collector, through the load to the emitter, which is connected to ground. In this condition, does the load operate? When a logic...
  13. DS2016

    Pnp transistor with base connected to collector

    Hello all, I have a problem to understand a pnp transistor with base (B) connected to collector (C). When I set the VE (voltage of emitter) at 0 V and the VB, which is the voltage of base and collector nodes, since they are tied together), decrease from 0 V to -1.0 V,the simulation result shows...
  14. S

    Efficiency of a PV module and solar thermal collector

    Does the efficiency of a PV module and solar thermal collector go down as ambient temperature (outside temperature) increases? I know there are other factors that influence efficiency, but I'm only considering the one parameter of temperature on a PV module and solar thermal collector.
  15. mooncrater

    Collector Current: Majority & Minority Carriers

    Homework Statement In my book ,I found this line which says ,"The collector current comprises two components-the majority and the minority carriers .The minority-current component is called the leakage current and is given the symbol ##I_{CO}## .The collector current, therefore is determined in...
  16. G

    Questions for common emitter, collector and base amplifier.

    Hello. I'm now studying transistor amplifier circuit and I have some confusion of definition of amplifier classification. I thought common emitter means emitter side is grounded, although there is actually some elements between emitter and ground in practice. So I thought "common" means...
  17. Rob1818

    BJT Collector to Emitter voltage

    I have been checking the BJTs on a car audio amplifier board with my DMM's diode test feature, and I need a little help understanding something I have been noticing: The base to emitter and base to collector voltage drops are present, and show an open circuit when the leads are reversed as they...
  18. I

    Difference between emitter and collector?

    Hi, i might have asked this previously but don't remember.in a BJT, could one treat the emitter as the collector and vice versa? if not, why not? what about JFETs? could one treat the drain as the source and the source as the drain?
  19. CKaiL

    How to find the density of collector saturation current?

    Homework Statement Given the following formula for saturation current Homework EquationsThe Attempt at a Solution I am able to find the value for Dn , q , WB , ni and N AB except for the A(cross sectional area)
  20. C

    Fuel Cell Collector: Optimizing Flow & Pressure

    Hi, I haven't posted anything on here in a long time, but thought somebody here could help me out. I am building a fuel system for an endurance sports car. I have a sealed 0.6 gallon collector in the fuel cell with three 75gph pumps, capable of 95psi feeding it, through 3/8" hose. It then...
  21. B0b-A

    The force was not strong enough to detect Darth Sidious

    So they used X-rays instead ... http://m.bbc.co.uk/news/uk-england-nottinghamshire-29627037
  22. M

    Transistors emitter collector flow

    Hello :-) I can't seem to get a good understanding about a part of transistors and how they act. What I think I know about transistors now is as follows: They're made up of npn or pnp called emitter, base and collector, and the junctions between them are emitter base junction and collector...
  23. J

    Heat transfer- Solar energy collector problem (took me 3 days, unsolve

    Homework Statement I have attached the problem as an image and they are same as below. The collector-receiver combination tested above is chosen for use in a solar thermal power plant. plant consists of 100 rows of collector-receiver modules. For the receiver efficiency use the value...
  24. ranju

    Explain Vceq & Icq in Collector-Base Bias Config.

    the base resistance in collector to base bias configuration is given by Rb=Vcc-Vbe-IcRl / Ib now , in a question only the value of Vceq is given & they found Rb as Rb=Vceq/Ib.! what is Vceq over here..?? and another quantity Icq is used..what are these two quantities..please explain a bit..
  25. ranju

    Base emitter voltage and collector current

    Does decrease in value of base-emitter voltage decreases collector current..?? As I studied that decrease in base-emitter voltage of some part of signal to lesser ammplification of that part due to smaller current..but how base emitter voltage is leading to less collector current.. because if...
  26. ajayguhan

    Base and collector of transistor

    which is light doped in transistor, whether it is base or collector ?
  27. D

    OP-Amp connected with Transistor whose Base and Collector are short

    Homework Statement Problem number 6a in the picture. Homework Equations Transistor: Ic = βIb Ic = αIe Ic = Is*e^(Vbe/nVt) OP-Amp: Vo = Acl*Vi Acl = 1 + (Rf/Ri) The Attempt at a Solution I tried to solve but just couldn't understand the behavior the transistor.
  28. H

    CE BJT Amplifier - Collector Resistance

    We are studying single transistor amplifiers, and in the text where the collector resistance of the CE amplifier, Ric, is derived, the final equation is Ric = ro[1+gm(Re||r∏)] (approximation) This equation is highlighted and emphasized as something we should remember, then shown again in...
  29. E

    Finding Voltage Gain in Common Collector Configuration Without RE

    Homework Statement for the common collector configuration shown i need to find the voltage gain. The voltage gain formula is AV = (β+1)(roll RE)/(rπ+(β+1)(roll RE) But in the circuit RE is absent . So how do we consider it ?? Nothing is given about the current source. from the circuit...
  30. C

    Probability of Collecting a New Type of Coupon After n Coupons Collected

    Homework Statement Suppose that you continually collect coupons and that there are m different types. Suppose also that each time a new coupon is obtained, it is a type i coupon with probability p_{i} , i = 1,.. m. Suppose you have just collected your n th coupon. What is the probability that...
  31. O

    Conceptual short circuit diode / zero-bias base collector junction BJT question

    Why exactly is there zero current flowing through a diode when it is short circuited, given the presence of the barrier potential? My current understanding is that the drift current precisely balances the diffusion current. But if you take a diode and short it with a wire, wouldn't you then also...
  32. S

    Emitter and Collector Resistance in Differential Amplifier.

    Hello experts! Image of Differential Amplifier is given below. Here in diff amp both transistor have same characteristics. Even +VCC and -VEE are of same magnitude. Everything is same. Hence, their RE and RC are also same. 1)If both emitter and collector resistance of both transistor...
  33. A

    Transistors: Collector vs Emitter (where does the symmetry get broken)

    I thought I had a good understanding of transistors, but I have seen articles on how to tell the collector from the emitter. I had always pictured transistors as a perfectly symmetrical device. Either side could be the collector, and the opposite side was the emitter. Clearly, there is some...
  34. S

    Bjt npn base collector junction breakdown

    When the NPN is in the forward active mode The base emitter junction is forward biased and the base collector junction is reverse biased. But isn't it possible for the base collector junction to break down? Or do we assume it never breaks down? Also does anyone know any good water analogies...
  35. B

    Solar Reactor using water tubes & dish collector.

    Hi, The dish is roof mounted and fixed. I want to heat water tubes coming from the base up to the focal point and I'm needing to know if this is sound or a tube coming from the base will never get enough focal point to heat it because it's fixed and not on a heliostat. Or, does the water...
  36. J

    Clipping and V supply and Voltage at collector of a transistor

    Hi, I am new here and I need some help on a massive project that has a large bearing on our end of year results. Its got to do with clipping of an output signal in a common emmitter BJT n-p-n Voltage Amplifier circuit. It asks us to comment on the clipping and relate it to Vs and Vc. Where Vs is...
  37. C

    Electromagnetic particle collector?

    Hey everyone, I am trying to develop a small electromagnet to pick up (relatively) large amounts small shavings which are roughly 70-80% Fe in composition and are roughly 10-40 microns in size. This device needs to be powered by a maximum of two D-Cell batteries (maybe we can look into alternate...
  38. Math Jeans

    How Does a GaAs Solar Collector Manage Light Absorption and Re-radiation?

    Homework Statement A flat and thin GaAs solar collector of 100 micrometer thickness is irradiated with 100mW of 650nm light (incident normal to the surface). The absorption coefficient is about 10^4 cm^-1 and the bandgap is 1.4 eV. Assume that the GaAs has ~100% internal quantum efficiency...
  39. F

    Heat Transfer solar collector system Problem

    I am planning a solar collector system for domestic hot water and heating. I am attempting to calculate the heat loss in a storage tank. If we assume: Tank Volume = 1m^3 Tank Surface Area = 6m^2 Tank Contents = 1000L water Initial Water Temp = 90C (194F) The Temp Outside the Tank = 10C...
  40. I

    Interior temperature of a solar collector

    Homework Statement A solar collector has an effective collecting area of 12 m^2. The collector is thermally insulated, and so conduction is negligible in comparison with radiation. On a cold but sunny winter's day the temperature outside is -20.0 C, and the Sun irradiates the collector with...
  41. J

    Infra Red Emittor and Collector

    Do infra red rays spread out or do they work the same as lasers and fire in a single ray? Example if I have the emittor at different distances from the object it is scanning (e.g a ground surface say 10mm and 30mm distances) do the rays spread and further to cover a wider range, or do they...
  42. E

    Does the Presence of Rc Affect the Voltage Gain in a Common Collector Amplifier?

    Normally in common collector amplifier, Rc (collector resistor) is absent or otherwise it is short circuited by capacitor. My question is: If Rc is present and not short circuited, does it affect the voltage gain? If it does, how it affects? Appreciate if someone can present clearly in...
  43. W

    Temperature funtion along X of a solar collector

    Homework Statement 1m wide solar heat collector that is x long. Find the temperature as a function of x. 500 W/m^2 transferred from the collector to the air within the collector, 100%. Air enters the collector has the following properties: cp = 1000 J/(kg*K) m = 0.02 kg/s...
  44. M

    Flat plate solar collector

    Homework Statement We wish to size a flat plate collector to provide water for one hot shower per hour. We have determined that a shower uses 80 liters of 40°C water that has been heated from a 15°C supply line. The receiver temperature must be greater than the desired water temperature of...
  45. D

    The collector is a high impedance when compared to the emitter.

    Good Morning can anyone help explain what this statement really means, when referring to a npn transistor in common mode, as an amplifier. "The collector is a high impedance when compared to the emitter" what's the pratical implication of this statement thanks David
  46. C

    Common collector and common emitter

    Hi, I am trying to build an amplifier with 2 stages, common collector and common emitter. I biased for midpoint operation in them but i have a gain of only 1, don't know where I am going wrong. http://yfrog.com/14amplifierunij Thats the circuit, any help is greatly appreciated
  47. M

    Clipping and V supply and Voltage at collector of a transistor

    Hi, I am new here, I'm still in high school here in Melbourne Australia, so please excuse my stupidity. Theres a question come up on a massive project that has a large bearing on our end of year results, its got to do with clipping of an output signal, and relating it to the Supply voltage...
  48. S

    Input and output resistance of common collector

    Homework Statement I don't understand how the website below got the equations for the output and input resistances Homework Equations http://www.statemaster.com/encyclopedia/Common-collector
  49. M

    Transistors for 3 Amps Saturation: What are My Options?

    the title says it all... my question is simple... are there transistors easily available that can be configured to provide upto 3ampers in the saturation region? if yes, whch ones?
  50. C

    Engineering Collector Current through BJT Circuit

    Homework Statement Consider the following circuit http://img109.imageshack.us/img109/80/circuit1.jpg IL, current through R3 (unknown resistance must be found) Homework Equations Vth=(Vcc/Rtotal)*R1 (V tThevenin) Rth=R1//R2 (R Thevenin) Vbe= 0.7 volts (silicon diode) Beta...