Explain the working of Neon sign tube with diagram.

Explain the working of Neon sign tube with diagram.
by

1 Answer

Answer :

Neon sign tube:

image

The construction & circuit diagram for neon tube is as shown in fig. Basically neon tube is used for advertisement or decoration purpose. The maximum length of tube is 8m. The available diameter for neon tubes are 5mm,10mm,15mm, 20mm, 30mm, etc. When the supply is switched on at primary, high voltage is induced in secondary winding of HT transformer. This voltage is applied across electrodes. At this high voltage, a discharge occurs in neon gas. In the neon tube, we can achieve various colours by changing the constituents of the gases and mercury filled in the tube. The choke is used for ballast & power factor improvement capacitor is also used. For the neon tube, continuous high voltage is required, so that following precautions should be taken.

* The neon tube should be installed by government authorized supervisor.

* The metal body of the HT transformer must be earthed separately.

* Caution notice of danger board is required.


by

Related questions

Explain the working of HPMV Lamp with neat diagram.

Description : Explain the working of HPMV Lamp with neat diagram.

Last Answer : High-pressure Mercury-Vapour Lamp (HPMVL):  Working:  * Whenever 1-ph, 230V, AC Supply is provided to the discharge tube of MVL, initially the current flows from Phase to the choke to ... : The function of power factor improvement capacitor is to improve the power factor from 0.5 to 0.95.

Describe the working principle of Thyristor operated dimmer with the help of circuit diagram.

Description : Describe the working principle of Thyristor operated dimmer with the help of circuit diagram.

Last Answer : Thyristor operated dimmer: A popular thyristor operated dimmer circuit employ TRIAC-DIAC phase control for low AC power control. During each half-cycle, the capacitor charges through (R1+VR1). When the ... time constant {C (R1+VR1)}. Thus by reducing VR1 the lamp brightness can be increased.

Explain with neat sketch the working principle of MIG.

Description : Explain with neat sketch the working principle of MIG.

Last Answer : In metal-arc inert gas welding the Weld area is shielded by an effectively inert atmosphere of argon, helium, carbon dioxide, or various other gas mixtures . The consumable bare Wire is fed automatically ... of the molten-weld puddle. Multiple-weld layers can be deposited at the joint. 

Draw the block diagram of regulated power supply, explain function of each block and draw waveforms of each stage.

Description : Draw the block diagram of regulated power supply, explain function of each block and draw waveforms of each stage.

Last Answer : 1. A step down transformer 2. A rectifier 3. A filter 4. A regulator Operation of Regulated Power Supply:- Step Down Transformer:- A step down transformer will ... regulator. A regulator will maintain the output constant even when changes at the input or any other changes occur.

With a neat sketch give the working of shaded pole induction motor.

Description : With a neat sketch give the working of shaded pole induction motor.

Last Answer : Explanation: It has squirrel cage rotor and salient pole stator. The stator poles are shaded partially by short circuited conductor band to create the phase difference between the fluxes emerging from shaded ... rotating magnetic field in the air-gap and torque is exerted on the squirrel cage rotor.

Explain the suitability of aluminium as an electrical conductor with respect to its mechanical and electrical properties.

Description : Explain the suitability of aluminium as an electrical conductor with respect to its mechanical and electrical properties. 

Last Answer : Following are requirements of conductor:- i) High conductivity :  Material should have high conductivity, So that * cross section of conductor (size) reduces, * Copper losses reduces, * So Efficiency ... . Boiling point is 1820°C 9. Specific gravity is 2.7 10. High resistance to corrosion. 

Explain the lighting scheme to be designed for each of the following: i) Special ward in hospitals ii) Dentist’s Cabin

Description : Explain the lighting scheme to be designed for each of the following: i) Special ward in hospitals ii) Dentist’s Cabin 

Last Answer : i) Special ward in hospital: For the patients in the wards, lighting should create a cozy and pleasant atmosphere. Lighting in the wards should be planned in such a way that it meets the specific ... we use such as cements and bonding agents that we use to restore your teeth back to health.

Explain the features of Aquarium lighting.

Description : Explain the features of Aquarium lighting. 

Last Answer : 1) The aquarium light depends upon the size of the aquarium tank (Length, width and depth)  2) The aquarium lighting depends upon the all surrounding condition e.g. colour and size of the given ... The aquarium lighting should be economical.  9) The life of the aquarium lighting should be long. 

Explain MCB and ELCB with connection diagram supplying single phase load.

Description : Explain MCB and ELCB with connection diagram supplying single phase load. 

Last Answer : OR OR Explanation: * MCB provides short circuit protection. * MCB provides overload protection * ELCB provides earth fault protection. * MCB is in series with ... occurs, the ELCB cuts off the power within the time of 0.1 sec. automatically to protect the personnel. 

Explain count up (CTU) instruction with timing diagram.

Description : Explain count up (CTU) instruction with timing diagram.

Last Answer : The CTU is an instruction that counts false-to-true rung transitions. Rung transitions can be caused by events occurring in the program. When rung conditions for a CTU instruction have made a false-to-true ... of Counter up(CTU) Instruction: Too many uploads - please try again in an hour

What is PLL? Explain its operation with a block diagram.

Description : What is PLL? Explain its operation with a block diagram.

Last Answer : PLL - A phase-locked loop or phase lock loop is a control system that generates an output signal whose phase is related to the phase of an input signal Block diagram  ... to the input frequency. The phase - locked loop goes through three states free running capture and phase lock.

Explain dynamic and static induced emf with neat diagram.

Description : Explain dynamic and static induced emf with neat diagram.

Last Answer : Dynamically Induced EMF:-  In this case, either coil moves or magnet moves, so that there is relative motion between coil & magnetic field. Thus magnetic field is cut by coil & emf is induced in it. The emf ... The expression for induced EMF is e= -L(di/dt) or = -N(dϕ/dt).

Draw block diagram of PLL as a FM demodulator. Explain function of each block.

Description : Draw block diagram of PLL as a FM demodulator. Explain function of each block.

Last Answer : Operation:  The FM signal which is to be demodulated is applied at the input of the PLL.  the PLL is locked to the FM  The error voltage produced at ... using PLL ensures a high Linearity, between the instantaneous input frequency and VCO control voltage (error amplifier output)

Explain construction and working of AC servomotor.

Description : Explain construction and working of AC servomotor.

Last Answer : Construction of AC Servo Motor: AC servo motor is mainly composed of a stator and a rotor. Laminated stator core is usually made of silicon steel. Two phase windings are placed in the stator slots at 90 degree ... on rotor. Due to the force or torque acting on the rotor, it is set in motion. 

Describe with neat sketch working of hysteresis motor.

Description : Describe with neat sketch working of hysteresis motor.

Last Answer : Working: When stator is energized with single phase ac supply, rotating magnetic field is produced because of starting (auxiliary) and main windings, which remain in circuit permanently. The ... the principle of magnetic locking this motor either rotates at synchronous speed or not at all.

Draw the block diagram of PLC.

Description : Draw the block diagram of PLC.

Last Answer : Block diagram of PLC and input/output devices used for PLC Input/output devices - The input module has bank of terminals for physically connecting input devices, like push buttons, limit switches etc. ... is to translate signals from the PLC's CPU into a form that the output device can use.

Give the working of MCCB.

Description : Give the working of MCCB.

Last Answer : Working of MCCB: ( Molded Case Circuit Breaker)  * The operating mechanism consisting of lever, spring, contacts etc. is used to open or close the MCCB electrically.  * The arc ... produced by short-circuit current operates the lever to trip the MCCB immediately and open the contacts. 

Illustrate with neat wiring diagram a single lamp control by two point method.

Description : Illustrate with neat wiring diagram a single lamp control by two point method.

Last Answer : Single lamp control by two point method:  This system is commonly used for stair case wiring. It consists of two way switches (the switch operates always in one of the two possible positions) the ... the person will change the position of switch S2, so that the lamp will be switched OFF'.

Draw the wiring diagram of fluorescent tube. Explain the working of choke and starter.

Description : Draw the wiring diagram of fluorescent tube. Explain the working of choke and starter. 

Last Answer : Fluorescent lamp:- Operation:- When switch is ON current flows through the choke-filament no1- starter-filament no. 2- to neutral, At that time choke induces high voltage which is applied to ... at the time of starting. ii) Starter: To make and break the circuit to start the tube. 

Define armature reaction in an alternator. Explain the effect of armature reaction at various P.F. of loads of alternator.

Description : Define armature reaction in an alternator. Explain the effect of armature reaction at various P.F. of loads of alternator.

Last Answer : Armature Reaction: The effect of armature flux on main flux is called as armature reaction.  Armature Reaction at Various Power Factors: When armature is loaded, the armature flux modifies ... lagging p.f. For capacitive loads the effect of flux is partly distorting and partly strengthening.

Explain the activities carried out during weekly maintenance of 3 ph. Induction motor.

Description : Explain the activities carried out during weekly maintenance of 3 ph. Induction motor. 

Last Answer : Activities Carried out During Weekly Maintenance of 3 ph. Induction Motor:  1) Check belt tension. In cases where this is excessive it should immediately be reduces and in the case of sleeve ... and cooled by oil mist systems its important to check the oil mist flow paths/pressure components.

Explain the concept of lagging and leading phase angle by waveform.

Description : Explain the concept of lagging and leading phase angle by waveform.

Last Answer : i) Leading phase angle :  When two ac quantities of same frequency do not attain their respective zero or peak values simultaneously, then the quantities are said to be out-of-phase quantities. The ... Similarly, in the second diagram, the voltage is said to be lagging the current by  Φ.

State the procedure for testing of earth pit resistance with necessary diagrams.

Description : State the procedure for testing of earth pit resistance with necessary diagrams.

Last Answer : Following procedure (Method) for testing of earth pit resistance with necessary diagrams. 1) Earth Tester : i) Three point method ii) Four point method 2) By Potential drop method 3 ... of that earthing pit. In this test the accuracy is less but electrical rods are not required. 

With the help of N-channel JFET describe the effect of input voltage VGS on output current ID.

Description : With the help of N-channel JFET describe the effect of input voltage VGS on output current ID.

Last Answer : Working of N channel FET: * When a voltage is applied between the drain and source with a DC supply (VDD), the electrons flows from source to drain through narrow channel ... where the channel gets completely blocked and the drain current becomes zero is called pinch- off voltage. 

Describe the concept of virtual ground with reference to op-Amp.

Description : Describe the concept of virtual ground with reference to op-Amp.

Last Answer : Virtual ground concept:-In circuit point A is virtual ground. Figure shows inverting amplifier using op-amp. In this circuit non-inverting terminal is connected to the actual ground. Due to ... zero potential without actually grounding is known as virtual ground concept. Circuit diagram: 

What is the smallest unit of a compound with the same chemical characteristics?

Description : What is the smallest unit of a compound with the same chemical characteristics?

Last Answer : The molecule is the smallest unit of a compound with the same chemical characteristics.

Explain working of AC circuit breaker using SCR with circuit diagram.

Description : Explain working of AC circuit breaker using SCR with circuit diagram.

Last Answer : AC Circuit Breaker:  The circuit configuration of static AC circuit breaker using SCR is shown in the figure. When switch S' is closed, the SCRs T1 and T2 are fired in positive ... to non-availability of gate current. Thus the maximum time delay for breaking the circuit is one half-cycle.

Explain with neat diagram the working of photo-voltaic cell.

Description : Explain with neat diagram the working of photo-voltaic cell. 

Last Answer : Diagram the working of photo-voltaic cell: Working:- Solar cell operates on principle of Photo-voltaic effect    Solar cell works in following steps: The solar cell is composed ... . When you connect loads such as a light bulb, electric current flows between the two electrodes.  

Explain construction & working of attraction type M.I. instrument with neat diagram.

Description : Explain construction & working of attraction type M.I. instrument with neat diagram.

Last Answer : 1. Moving element: a small piece of soft iron in the form of a vane or rod.  2. In Attracted type a cylindrical coil or solenoid which is kept fixed. An oval-shaped soft-iron piece are ...   9. When = the pointer will be stable & we can get correct reading of the electrical quantity

Draw symbol of LED and explain it’s working principle.

Description : Draw symbol of LED and explain it’s working principle.

Last Answer : Construction of LED: The basic structure of LED is shown in fig.(a). The active region exists between the p and n regions. The light emerges from the active side in all the directions when electron hole-pairs ... fig.(c). In this way an LED emits light. This is the principle of operation of LED.

State the requirements of illumination scheme of shipyard.

Description : State the requirements of illumination scheme of shipyard.

Last Answer : Requirements of illumination scheme of shipyard:  1) The shipyard lighting always depends upon the surrounding conditions. e.g. wind pressure, rain fall, location of shipyard from the sea-share etc. ... solar grass lamps, LED-Solar energy lawn lamps, various focus lamps, metal halide lamps etc.

State the various lighting calculations methods and Describe any one of them.

Description : State the various lighting calculations methods and Describe any one of them.

Last Answer : Lighting calculation methods: 1. Lumens or Light flux method 2. Point to point or Inverse Square law method 3. Watts per Square meter method i) Lumens or Light ... is taken according to the illumination desired on an average value considering overall efficiency of the lighting system.

State the different types of outdoor flood lighting and where are they used.

Description : State the different types of outdoor flood lighting and where are they used.

Last Answer : There are three types of projectors used for flood lighting :  a) Narrow beam Projector b) Medium angle Projector c) Wide angle Projector a) Narrow beam Projectors: - Light beam with such ... yards, stadiums, car parking area etc. 3) It is used for illuminating advertisements, boarding's etc.

State the purpose of lighting control. List the different types of dimmer.

Description : State the purpose of lighting control. List the different types of dimmer.

Last Answer : Purpose of Lighting Control:- 1. To turn ON or OFF the lamps 2. For dimming: The dimming control permits the adjustment of lighting over a range. 3. For changing the lighting levels ... operated dimmer 6) Triac operated Dimmer 7) PWM (Pulse width modulation) Controlled technique.

Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life.

Description : Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life. 

Last Answer : 1) Effect on Current:- In LED current depends upon supply voltage, if voltage get changes then current also change but this change in current will be control by resistors which are connected in series.  2) ...   4) Effect on Life:- If supply voltage is not stable then life of LED get reduced. 

State the selection criterion of the lamp for various purposes.

Description : State the selection criterion of the lamp for various purposes.

Last Answer : Selection criterion of the lamp for various purposes:  While selecting a lamp for a particular purpose, the available lamps are compared on the basis of following criteria: * Light output ... such as ballasts * Compatibility with the electrical system * Suitability for the operating environment

Compare the salient features of LED and CFL based on: i] Lamp Efficiency ii] Life span

Description :  Compare the salient features of LED and CFL based on: i] Lamp Efficiency ii] Life span 

Last Answer : Parameter LED CFL Lamp Efficiency  High (more than 70 lumen per watt) Comparatively less (50-60 lumen per watt) Life span (in working hours) 10000 3000

Describe strain gauge with labelled diagram.

Description : Describe strain gauge with labelled diagram.

Last Answer : A Strain gauge is a sensor whose resistance varies with applied force. It converts force, pressure, tension, weight, etc., into a change in electrical resistance which can then be measured. When external ... to the applied strain. So, the voltmeter can be calibrated in terms of strain or force. 

Block Diagram of op-Amp

Description : Block Diagram of op-Amp

Last Answer : Block Diagram: The OP-AMP is basically a different amplifier i.e. it will amplify the voltage which is differentially present between its input terminals.  1.Input stage: The ... normally a complementary output stage. It increases the OPAMP. It also provides a low output resistance. 

Source transformation Replace the circuit with voltage source in series with a single resistor

Description : Source transformation Replace the circuit with voltage source in series with a single resistor

Last Answer : Source transformation Replace the circuit with voltage source in series with a single resistor

Explain any four properties of Moulding sand.

Description : Explain any four properties of Moulding sand. 

Last Answer : 1. Porosity: Molten metal always contain a certain amount of dissolved gases, which are evolved when the metal freezes the molten metal coming in contact with the moist sand , generates steam or ... to the casting. Refractoriness is measured by the sinter point of the sand rather than its melting

List different starting methods of three phase synchronous motor. Explain any one of them.

Description : List different starting methods of three phase synchronous motor. Explain any one of them.

Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor. 

Draw & explain operation of phase detector.

Description : Draw & explain operation of phase detector.

Last Answer : In phase detector, the op-Amp basically acts as a zero crossing detector. If a sine wave is applied at the i/p, we get square wave at the op-Amp o/p (at point ... to two channel of the CRO. The time duration between the pulses corresponding to voltages represent the phase between them. 

State two applications of : (i) PVC paper (ii) Porcelain with type of class based on withstand temperature is insulating material.

Description : State two applications of : (i) PVC paper (ii) Porcelain with type of class based on withstand temperature is insulating material. 

Last Answer :  (i) Application of PVC paper : 1. It is used in slot lining or motor winding insulation purpose 2. For Insulation of Transformer winding (ii) Application of Porcelain : 1. Mainly used for manufacturing ... on withstand temperature : * H' & C' Class of insulation i e. 180° and above 180°C 

Neon Glow Sticks

Description : Neon Glow Sticks

Last Answer : Glow sticks are not only useful in different party situations, the neon light they emit also open doors to artistry and creative expressions. Although a glow stick cannot be recharged, the glow lasts for a ... , so why ingest it? The newer glow sticks being produced today are said to be non-toxic.

Which is a semiconductor: copper, silicon, or neon?

Description : Which is a semiconductor: copper, silicon, or neon?

Last Answer : Copper is a metal. Silicon is a semiconductor. Neon is inert gas.

State the procedure for laying / installation of underground cable.

Description : State the procedure for laying / installation of underground cable.  

Last Answer : 1) Direct laying Cable: or Trench laying method: Procedure: * For laying of a cable trench about 1.5m deep and 0.5m wide is made along the cable route. * A ... over. * Cables laid in this manner are usually plain lead covered because troughing affords good mechanical protection. 

State any two advantages of MCB over Fuse. State the standard specifications of MCB available in the market.

Description : State any two advantages of MCB over Fuse. State the standard specifications of MCB available in the market.  

Last Answer : Following advantages of MCB over Fuse: 1. No need of replacement of fuse wire. 2. Manually restore of supply is simple. 3. Fault understanding by visual inspection 4. More safe than fuse The standard specifications of ... 6A, 10A,16A,20A, 25A, 30A, 32A, 40A, 50A, 60A and 63A 6. 250V and 450 v

State the type of insulating materials under Class Y and Class B.

Description : State the type of insulating materials under Class Y and Class B.

Last Answer : The type of insulating materials under Class Y : 1. Cotton  2. Silk 3. Paper 4. Rubber 5. PVC The type of insulating materials under Class B: 1. Backelite 2. Impregnated varnish 3. Mica 4. Fiber glass 5. Asbestos 

State the types of protections provided by MCB.

Description : State the types of protections provided by MCB. 

Last Answer : The types of protections provided by MCB: 1. MCB provides short circuit protection. 2. MCB provides overload protection