Firing angle of UJT as an oscillator Thyristor firing circuit Calculator

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✖Angular frequency in radians/sec is used calculating the angular frequency by using pi as 3.14.ⓘ Angular frequency in radians/sec [w]			+10% -10%
✖Resistance is a measure of the opposition to current flow in an electrical circuit. Its S.I unit is ohm.ⓘ Resistance [R]			+10% -10%
✖Capacitance is the ratio of the amount of electric charge stored on a conductor to a difference in electric potential.ⓘ Capacitance [C]			+10% -10%
✖Intrinsic stand-off ratio UJT as Oscillator is defined as the ratio of emitter base 1 resistance to the total emitter base junctions resistances.ⓘ Intrinsic stand-off ratio UJT as Oscillator [η]			+10% -10%

✖Firing angle is the angle in the AC cycle at which the thyristor starts conducting at the application of positive voltage to gate.ⓘ Firing angle of UJT as an oscillator Thyristor firing circuit [α]

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Parminder Singh

Chandigarh University (CU), Punjab

Parminder Singh has created this Calculator and 50+ more calculators!

Rachita C

BMS College Of Engineering (BMSCE), Banglore

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Firing angle of UJT as an oscillator Thyristor firing circuit Solution

STEP 0: Pre-Calculation Summary

Formula Used

Firing Angle = Angular frequency in radians/sec*((Resistance*Capacitance)*ln(1/(1-Intrinsic stand-off ratio UJT as Oscillator)))
α = w*((R*C)*ln(1/(1-η)))
This formula uses 1 Functions, 4 Variables

Functions Used

ln - Natural logarithm function (base e), ln(Number)

Variables Used

Angular frequency in radians/sec - Angular frequency in radians/sec is used calculating the angular frequency by using pi as 3.14. (Measured in Radian per Second)
Resistance - Resistance is a measure of the opposition to current flow in an electrical circuit. Its S.I unit is ohm. (Measured in Ohm)
Capacitance - Capacitance is the ratio of the amount of electric charge stored on a conductor to a difference in electric potential. (Measured in Farad)
Intrinsic stand-off ratio UJT as Oscillator- Intrinsic stand-off ratio UJT as Oscillator is defined as the ratio of emitter base 1 resistance to the total emitter base junctions resistances.

STEP 1: Convert Input(s) to Base Unit

Angular frequency in radians/sec: 10 Radian per Second --> 10 Radian per Second No Conversion Required
Resistance: 10 Ohm --> 10 Ohm No Conversion Required
Capacitance: 3 Farad --> 3 Farad No Conversion Required
Intrinsic stand-off ratio UJT as Oscillator: 0.5 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

α = w*((R*C)*ln(1/(1-η))) --> 10*((10*3)*ln(1/(1-0.5)))

Evaluating ... ...

α = 207.944154167984

STEP 3: Convert Result to Output's Unit

207.944154167984 Radian -->11914.3224082454 Degree (Check conversion here)

FINAL ANSWER

11914.3224082454 Degree <-- Firing Angle

(Calculation completed in 00.016 seconds)

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Firing angle of UJT as an oscillator Thyristor firing circuit

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Excess work due to thyristor 1 in chopper circuit

Excess energy in chopper circuit = 0.5*Reverse di/dt limiting inductance*((Load current of chopper circuit+(Reverse recovery time*Commutation capacitor voltage)/Reverse di/dt limiting inductance)-(Load current of chopper circuit^2)) Go

Worst case steady state voltage across first thyristor in series connected thyristors

Worst case steady state voltage of thyristor 1 = ((Resultant series voltage of thyristor string+(Number of thyristors in series thyristor string-1)*Resistance*Off state current spread of thyristor string))/Number of thyristors in series thyristor string Go

Voltage across first thyristor in series-connected thyristors

Voltage across thyristor 1 in thyristor string = (Resultant series voltage of thyristor string+(Number of thyristors in series thyristor string-1)*Resistance*Off state current spread of thyristor string)/Number of thyristors in series thyristor string Go

Resultant series voltage of series connected thyristor string

Resultant series voltage of thyristor string = Number of thyristors in series thyristor string*Voltage across thyristor 1 in thyristor string-(Number of thyristors in series thyristor string-1)*Resistance*Off state current spread of thyristor string Go

Maximum Thyristor gate voltage for resistance firing circuit

Maximum gate voltage = Maximum AC input voltage*(Stabilizing Resistance/(Stabilizing Resistance+Variable Resistance+Resistance)) Go

Derating factor of series connected thyristor string

Derating factor of thyristor string = 1-(Resultant series voltage of thyristor string/(Number of thyristors in series thyristor string*Worst case steady state voltage of thyristor 1)) Go

Power dissipated by heat in SCR

Power dissipated by heat in SCR = (SCR junction temperature-SCR ambient temperature)/Thermal resistance of SCR Go

Thermal resistance of SCR

Thermal resistance of SCR = (SCR junction temperature-SCR ambient temperature)/Power dissipated by heat in SCR Go

Leakage current of the collector-base junction

Collector to base leakage current = Collector current-Common base current gain of transistor*Emitter current Go

Discharging current of dv/dt protection thyristor circuits

Discharging current of thyristor circuit = Input voltage/((Resistance+Resistance)) Go

Firing angle of UJT as an oscillator Thyristor firing circuit Formula

Firing Angle = Angular frequency in radians/sec*((Resistance*Capacitance)*ln(1/(1-Intrinsic stand-off ratio UJT as Oscillator)))
α = w*((R*C)*ln(1/(1-η)))

Applications of UJT.

An UJT or Unijunction Transistor find many applications just in the domain of power electronics and some of them are :
Relaxation oscillators.
Switching Thyristors like SCR, TRIAC etc.
Magnetic flux sensors.
Voltage or current limiting circuit.
Bistable oscillators.
Voltage or current regulators.
Phase control circuits.

How to Calculate Firing angle of UJT as an oscillator Thyristor firing circuit?

Firing angle of UJT as an oscillator Thyristor firing circuit calculator uses Firing Angle = Angular frequency in radians/sec*((Resistance*Capacitance)*ln(1/(1-Intrinsic stand-off ratio UJT as Oscillator))) to calculate the Firing Angle, The Firing angle of UJT as an oscillator Thyristor firing circuit formula is defined as as the angle at which the injection of voltage at gate terminal of thyristor causes it to starts conducting. Firing Angle is denoted by α symbol.

How to calculate Firing angle of UJT as an oscillator Thyristor firing circuit using this online calculator? To use this online calculator for Firing angle of UJT as an oscillator Thyristor firing circuit, enter Angular frequency in radians/sec (w), Resistance (R), Capacitance (C) & Intrinsic stand-off ratio UJT as Oscillator (η) and hit the calculate button. Here is how the Firing angle of UJT as an oscillator Thyristor firing circuit calculation can be explained with given input values -> 11914.32 = 10*((10*3)*ln(1/(1-0.5))).

FAQ

What is Firing angle of UJT as an oscillator Thyristor firing circuit?

The Firing angle of UJT as an oscillator Thyristor firing circuit formula is defined as as the angle at which the injection of voltage at gate terminal of thyristor causes it to starts conducting and is represented as α = w*((R*C)*ln(1/(1-η))) or Firing Angle = Angular frequency in radians/sec*((Resistance*Capacitance)*ln(1/(1-Intrinsic stand-off ratio UJT as Oscillator))). Angular frequency in radians/sec is used calculating the angular frequency by using pi as 3.14, Resistance is a measure of the opposition to current flow in an electrical circuit. Its S.I unit is ohm, Capacitance is the ratio of the amount of electric charge stored on a conductor to a difference in electric potential & Intrinsic stand-off ratio UJT as Oscillator is defined as the ratio of emitter base 1 resistance to the total emitter base junctions resistances.

How to calculate Firing angle of UJT as an oscillator Thyristor firing circuit?

The Firing angle of UJT as an oscillator Thyristor firing circuit formula is defined as as the angle at which the injection of voltage at gate terminal of thyristor causes it to starts conducting is calculated using Firing Angle = Angular frequency in radians/sec*((Resistance*Capacitance)*ln(1/(1-Intrinsic stand-off ratio UJT as Oscillator))). To calculate Firing angle of UJT as an oscillator Thyristor firing circuit, you need Angular frequency in radians/sec (w), Resistance (R), Capacitance (C) & Intrinsic stand-off ratio UJT as Oscillator (η). With our tool, you need to enter the respective value for Angular frequency in radians/sec, Resistance, Capacitance & Intrinsic stand-off ratio UJT as Oscillator and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Firing Angle?

In this formula, Firing Angle uses Angular frequency in radians/sec, Resistance, Capacitance & Intrinsic stand-off ratio UJT as Oscillator. We can use 1 other way(s) to calculate the same, which is/are as follows -

Firing Angle = asin(Gate threshold voltage*((Resistance+Stabilizing Resistance+Variable Resistance)/(Maximum AC input voltage*Stabilizing Resistance)))

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