ट्यूब लाइट का कार्य करने का सिद्धान्त

ट्यूब लाइट का कार्य करने का सिद्धान्त 

ट्यूब लाइट में चोक स्टार्टर  और ट्यूब रॉड के दोनों साइड के फिलामेंट सिरीज़ में कनेक्ट होते हें ट्यूब लाइट रॉड में दो फिलमेंट होते हें जेसे ही सप्लाई ऑन करते हें करंट चोक स्टार्टर और फिलामेंट से बहने लगती हे ।
फिलमेंट गरम होने से इलेक्ट्रोन निकलते हें जब स्टॉर्टर के द्वारा सर्किट ब्रेक होता हे तो चोक से हाई वोल्टेज पैदा होता है जिससे रॉड के अंदर इलेक्ट्रोन एक साइड से दूसरे साइड तेजी से बहने लगते है ये इलेक्ट्रोन कांच के अंदर फ्लोरोसेंट कोटिंग से टकराते हे जिससे रोसनी पैदा होती हे। ट्यूब लाइट स्टार्ट होने के बाद चोक ट्यूब लाइट की करंट को कंट्रोल करके रखता हे। रनिंग  के समय रॉड को 110 वोल्ट मिलता हे बाकि वोल्टेज चोक ड्राप कर लेता हे। साधारणतः ट्यूब लाइट होल्डर या स्टार्टर होल्डर में लूज़ कांटेक्ट होने से लाइट नहीं जलती हे जिसे स्टार्टर या रॉड को घूमाने से ठीक हो जाती हे। कभी कभी रॉड दोनों साइड ग्लो करती हे पर स्टार्ट नहीं होती ये स्टार्टर शार्ट होने से होता हे स्टार्टर चेंज करने से ओके हो जाती हे। ट्यूब रॉड पुरानी हो कर कमजोर हो जाने से लहरा कर चलती है तब ट्यूब रॉड बदलने से ठीक हो जाती है। यदि इससे काम न बने तो सभी सामान को मल्टी मीटर या सिरीज़ लैंप से टेस्ट कर के देखे जो सामान कॉन्टीन्यूटी नहीं दिखाये उसे चेंज कर दे लाइट ठीक हो जायेगी ।

आपके सुझाव आमंत्रित हैं

http://vijayelectronicsforu.blogspot.com/2018/08/star-delta-starter-principle-circuit.html

Star Delta Starter Principle Circuit Diagram and Explanation

Star Delta Starter Principle Circuit Diagram and Explanation

Introduction:- A three phase motor has three windings with terminal numbers A1-A2, B1-B2 and C1,C2. In some motor terminal numbers are U1-U2, V1-V2 and W1-W2. These three winding can be connected in two way known as star connection or delta connection. In motor name plate we can get motor type as three phase ac induction motor, kw as 5kw 10 kw, voltage 230 or 400, star or delta conection full load current power factor efficiency duty cycle etc.

Star connection:- In star connection the second point of each winding ie A2, B2, C2 are conected (shorted) to each other making a point known as star point. And remaining three points A1, B1, C1 are connected to 3 phase supply points R phase Y phase and B phase respectively. The connection is as shown in diagram. In star connection the voltage given to each winding known as phase voltage is equal to line voltage/1.732 (root 3). And phase current is equal to line current.

Delta connection:- In Delta connection the second point A2 of first winding is connected to first point B1 of second winding. Again the second point B2 of second winding is connected to first point C1 of third winding. And second point C2 of third winding is connected to first point A1 of first winding. It forms a tringle shape closed circuit by three  winding as arm of tringle thats why it is known as Delta connection. In delta connection winding phase voltage is equal to line voltage of supply. But the phase current is line current/root 3.

So as per name plate voltage and connection a motor can be connected in star or delta connection.
If a motor name plate shows delta connection then  it can be run first  in star  and then in delta.This motor can be used with star delta starter.
If a motor is 400 volt star connection it can not be used with star delta starter because motor can not connected in delta connection.

Principle of star delta starter:- while starting a motor 3 phase supply is given to motor by contactor. While giving direct full voltage to motor causes very high current which causes line voltage drop. To reduce starting current a method used is known as reduce voltage starting and full voltage runnung scheme is used. This is achieved by two way ie

l. by using star delta starter
2. by using auto transformer srarter

Here we will discuss star delta strater.

In old time manual star delta starter was used. but now automatic star delta starters are used.

Construction;- It consist of three starter and one time relay and two push button overload relay. all parts are connected as shown in circuit diagram.

When start button is pressed contactor c1 and c3 pick up and motor start in star conection with reduced voltage taking low current. after few seconds when motor picks up speed time relay oprates and contactor c3 drops and c2 pickup which changes motor connection to delta. now motor runs at full voltage. The overload relay provides protection against overload condition by trippning the motor. When stop button pressed both the contactors drop and motor stops.time relay coil is connected in parallen with c1 contactor coil. c2 and c3 nc contact is used in interlocking so that c2 can pick up only when c3 gets drop.similarly c3 can only pick up when c2 is drop.
I hope this will help full to you. please comment for any more information.


http://electronicsandmicrocontroller.blogspot.com/2018/07/a-simple-arduino-program-blinking-led.html

http://electronicsandmicrocontroller.blogspot.com/2018/07/three-phase-welding-rectifier-circuit.html

Kirchoff's current law and Kirchoff's voltage law

Kirchoff's current law also known as kirchoff's point law or Kirchoff's junction law. It states that total algebric sum of current flowing to / away from a junction (point) is equals to zero. That is at any point in a circuit total incoming current is equal to total out going current. With the help of this we can find out the current in a branch of circuit if other branch currents are known.for example  if  a point has three branches and incoming current from branch 1 is 4 ampere. and out going current from branch 2 is 1 ampere. then the current from banch 3 is 4-1 = 3 ampere out going.

Kirhoff's voltage law or mesh law. it states that in any closed mesh (circuit) the algebric sum of all voltage rise or drop is equals to zero.

Voltage rise:- in a circuit if we move through cell in negative to positive direction it is voltage rise and  from positive to negative it is voltage drop.

In other circuit elements if we move in the direction of current flow it is considered as voltage drop. if we move in direction opposite to current flow it is considered as voltage rise.

Cloes circuit or mesh:- In any complex circuit we can divide it in to many closed loop. A closed loop is any path in circuit in which we start from a point and return back to same point.
with the help of using these two laws the current flowing in all branches of network can be calculated easily. A circuit diagram is given below.

In the circuit diagram shown above we can apply kirchoffs current law at any point. at poit B there are three current ie I, I1 and I2 according to KCL 

I = I1 + I2  --------- (1)

Similarly at point E

I = I1 + I2  --------- (2) n 

There are three loops (mesh or closed circuit) in diagram

first loop ABCDEFA in cyan color for which voltage equation is

V = I1R1 + I1R2 + I1R3    --------- (3)

Second loop BGHKEDCB

in this loop there is no voltage source. we start from point B and complete the loop in clock wise direction. When we move in direction of current there is voltage drop and we give it a negative sign.

When we move in a direction opposite to direction of current there is voltage rise and we give it a positive sign.

In resistance R4 and R5 there is voltage drop. in resistamce R1 R2 and R3 there is voltage rise so equation is

V4 + V5 - V3 -V2 - V1 = 0  ------(4)

I2R4 + I2 R5 - I1R3 - I1R2 - I1R1 -----(5)

Third loop ABGHKEFA

V - V4 -V5 = 0  -----(6)

V = V4 + V5   -------(7)

V = I2R4 + I2 R5  ------(8)

With the above equations value of I1 and I2 can be determined.

Above is simple circuit but any circuit can be solved.

3 Phase Induction Motor Direct On Line Starter

3 Phase Induction Motor Direct On Line Starter 

Introduction:- 3 phase induction motors comes in the range of  0.5 hp to 200 hp and above. Depends on load motors power requirement is decided. Motor starters are used to safely start/stop motor either locally from near motor or remotely from control room. Many operational interlockings are also used in industries where complex process in involved. Now a days programable logic controller (PLC) are also used for control interlockings. In industries where large motors are used very big high current capacity MCC are used to control motors operation. When MCC current capacity is very high the motors can be started directly with dol starting principle where direct 3 phase supply is given to motor with the help of contactor. But in cities where supply comes from pole through cable high starting current of dol is not acceptable so we use different starting methods.

1 motors up to 5 hp direct on line starter is used
2 motors above 10 hp
        a. star delta starter   b auto transformer starter

In this post i am taking direct online starter

Circuit Diagram:-

As told above the starting current of small motors is less so dol stater is used safely.
normally a main switch or mcb is used as main power on off switch. A electromagnetic contactor is used to on/off three phase power to motor with start / stop switch. an over load relay is used to protect motor from operational over load .

Electromagnetic contactor:- It has a coil and set of no and nc contacts. coil is generally rated for 230 volt ac or 400 volt ac. There are three normally open power contacts used in power circuit of motor. Two sets of no and nc contact used for holding circuit, interlocking and indication circuit.

Start push nutton :- It has two contacts one no and one nc. The no contact is used in circuit. when start button is pressed supply goes to coil and contactor picks up. As soon as contactor picks up three phase supply goes to motor through three power contacts and motor starts. Also one no contact connected in parallel of start button is closed which maintains the supply to coil even after releasing the start button and motor runs continously. this contact is known as holding contact as it keeps contactor holdon.

Stop button:- It has two contacts one no one nc. Its nc contact is used in control circuit. As stop button is preesed the supply to contactor coil brakes and contactor drops out and motor stops.

Over Load Relay:- Over Load relay has three input power terminals and three output power terminals and one change over contact for control circuit. Overload relay input power terminal are connected to output of contactor. The output power terminals are connected to  motor power terminal with the help of cable. And the nc contact is used in control circuit in series with stop button. While running of motor if motors load is increased beyond overload set current value the overload operate and its nc contact becomes open so contactor drop out and hence motor stops (tripped)
so that overload relay protect motor from over load conditions.

Power fuse:- Power fuses are used to protect circuit from any short circuit in cable or motor. In case of any short circuit power fuse blown out and safe the other items from damage.

Control fuse or control mcb:- Generally used in mcc control panels where it needs to test circuit with out power. In case of some short circuit in control line control fuse blows out. Thanks



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