Thermal Resistance of SCR Calculator

✖Junction temperature is defined as the temperature of the junction of a SCR due to movement of charge.ⓘ Junction Temperature [T_junc]			+10% -10%
✖Ambient temperature is defined as the temperature of the surroundings of the SCR.ⓘ Ambient Temperature [T_amb]			+10% -10%
✖Power Dissipated by Heat in SCR is defined as the average of the total heat generated at the junctions of the SCR due to movement of charge.ⓘ Power Dissipated by Heat [P_dis]			+10% -10%

✖Thermal resistance of SCR is defined as the the ratio of the temperature difference between the two faces of a material to the rate of heat flow per unit area in a SCR.ⓘ Thermal Resistance of SCR [θ]

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Formula

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Thermal Resistance of SCR

Formula

`"θ" = ("T"_{"junc"}-"T"_{"amb"})/"P"_{"dis"}`

Example

`"1.496761K/W"=("10.2K"-"5.81K")/"2.933W"`

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Thermal Resistance of SCR Solution

STEP 0: Pre-Calculation Summary

Formula Used

Thermal Resistance = (Junction Temperature-Ambient Temperature)/Power Dissipated by Heat
θ = (T_junc-T_amb)/P_dis
This formula uses 4 Variables

Variables Used

Thermal Resistance - (Measured in Kelvin per Watt) - Thermal resistance of SCR is defined as the the ratio of the temperature difference between the two faces of a material to the rate of heat flow per unit area in a SCR.
Junction Temperature - (Measured in Kelvin) - Junction temperature is defined as the temperature of the junction of a SCR due to movement of charge.
Ambient Temperature - (Measured in Kelvin) - Ambient temperature is defined as the temperature of the surroundings of the SCR.
Power Dissipated by Heat - (Measured in Watt) - Power Dissipated by Heat in SCR is defined as the average of the total heat generated at the junctions of the SCR due to movement of charge.

STEP 1: Convert Input(s) to Base Unit

Junction Temperature: 10.2 Kelvin --> 10.2 Kelvin No Conversion Required
Ambient Temperature: 5.81 Kelvin --> 5.81 Kelvin No Conversion Required
Power Dissipated by Heat: 2.933 Watt --> 2.933 Watt No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

θ = (T_junc-T_amb)/P_dis --> (10.2-5.81)/2.933

Evaluating ... ...

θ = 1.49676099556768

STEP 3: Convert Result to Output's Unit

1.49676099556768 Kelvin per Watt --> No Conversion Required

FINAL ANSWER

1.49676099556768 ≈ 1.496761 Kelvin per Watt <-- Thermal Resistance

(Calculation completed in 00.004 seconds)

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Created by Parminder Singh

Chandigarh University (CU), Punjab

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BMS College Of Engineering (BMSCE), Banglore

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< 5 SCR Performance Parameters Calculators

Worst Case Steady State Voltage across First Thyristor in Series Connected Thyristors

Go Worst Case Steady State Voltage = (Resultant Series Voltage of Thyristor String+Stablizing Resistance*(Number of Thyristors in Series-1)*Off State Current Spread)/Number of Thyristors in Series

Derating Factor of Series Connected Thyristor String

Go Derating Factor of Thyristor String = 1-Resultant Series Voltage of Thyristor String/(Worst Case Steady State Voltage*Number of Thyristors in Series)

Leakage Current of Collector-Base Junction

Go Collector Base Leakage Current = Collector Current-Common-Base Current Gain*Collector Current

Power Dissipated by Heat in SCR

Go Power Dissipated by Heat = (Junction Temperature-Ambient Temperature)/Thermal Resistance

Thermal Resistance of SCR

Go Thermal Resistance = (Junction Temperature-Ambient Temperature)/Power Dissipated by Heat

< 16 SCR Characteristics Calculators

Worst Case Steady State Voltage across First Thyristor in Series Connected Thyristors

Go Worst Case Steady State Voltage = (Resultant Series Voltage of Thyristor String+Stablizing Resistance*(Number of Thyristors in Series-1)*Off State Current Spread)/Number of Thyristors in Series

Thyristor Commutation Voltage for Class B Commutation

Go Thyristor Commutation Voltage = Input Voltage*cos(Angular Frequency*(Thyristor Reverse Bias Time-Auxiliary Thyristor Reverse Bias Time))

Derating Factor of Series Connected Thyristor String

Go Derating Factor of Thyristor String = 1-Resultant Series Voltage of Thyristor String/(Worst Case Steady State Voltage*Number of Thyristors in Series)

Time Period for UJT as Oscillator Thyristor Firing Circuit

Go Time Period of UJT as Oscillator = Stablizing Resistance*Capacitance*ln(1/(1-Intrinsic Stand-off Ratio))

Emitter Current for UJT based Thyristor Firing Circuit

Go Emitter Current = (Emitter Voltage-Diode Voltage)/(Emitter Resistance Base 1+Emitter Resistance)

Circuit Turn off Time Class B Commutation

Go Circuit Turn Off Time Class B Commutation = Thyristor Commutation Capacitance*Thyristor Commutation Voltage/Load Current

Frequency of UJT as Oscillator Thyristor Firing Circuit

Go Frequency = 1/(Stablizing Resistance*Capacitance*ln(1/(1-Intrinsic Stand-off Ratio)))

Thyristor Conduction Time for Class A Commutation

Go Thyristor Conduction Time = pi*sqrt(Inductance*Thyristor Commutation Capacitance)

Peak Current Class B Thyristor Commutation

Go Peak Current = Input Voltage*sqrt(Thyristor Commutation Capacitance/Inductance)

Intrinsic Stand-off Ratio for UJT based Thyristor Firing Circuit

Go Intrinsic Stand-off Ratio = Emitter Resistance Base 1/(Emitter Resistance Base 1+Emitter Resistance Base 2)

Circuit Turn off Time Class C Commutation

Go Circuit Turn Off Time Class C Commutation = Stablizing Resistance*Thyristor Commutation Capacitance*ln(2)

Leakage Current of Collector-Base Junction

Go Collector Base Leakage Current = Collector Current-Common-Base Current Gain*Collector Current

Power Dissipated by Heat in SCR

Go Power Dissipated by Heat = (Junction Temperature-Ambient Temperature)/Thermal Resistance

Thermal Resistance of SCR

Go Thermal Resistance = (Junction Temperature-Ambient Temperature)/Power Dissipated by Heat

Discharging Current of dv-dt Protection Thyristor Circuits

Go Discharging Current = Input Voltage/((Resistance 1+Resistance 2))

Emitter Voltage to Turn On UJT based Thyristor Firing Circuit

Go Emitter Voltage = Emitter Resistance Base 1 Voltage+Diode Voltage

Thermal Resistance of SCR Formula

Thermal Resistance = (Junction Temperature-Ambient Temperature)/Power Dissipated by Heat
θ = (T_junc-T_amb)/P_dis

What are losses in SCR?

All diodes and transistors are characterized by power losses due to switching and conduction. Switching losses occur during the interval between the on- and off-states of a junction, when there is both a voltage across the device terminals and a current flowing through it. Conduction losses are due to the device’s internal resistance that, no matter how low it is, will result in a power loss when a current is flowing. Even in the off-state, losses due to transistor leakage currents can be significant in devices such as microprocessors.

How to Calculate Thermal Resistance of SCR?

Thermal Resistance of SCR calculator uses Thermal Resistance = (Junction Temperature-Ambient Temperature)/Power Dissipated by Heat to calculate the Thermal Resistance, The Thermal resistance of SCR formula is defined as the ratio of the temperature difference between the two faces of a material to the rate of heat flow per unit area in a SCR. Thermal Resistance is denoted by θ symbol.

How to calculate Thermal Resistance of SCR using this online calculator? To use this online calculator for Thermal Resistance of SCR, enter Junction Temperature (T_junc), Ambient Temperature (T_amb) & Power Dissipated by Heat (P_dis) and hit the calculate button. Here is how the Thermal Resistance of SCR calculation can be explained with given input values -> 1.496761 = (10.2-5.81)/2.933.

FAQ

What is Thermal Resistance of SCR?

The Thermal resistance of SCR formula is defined as the ratio of the temperature difference between the two faces of a material to the rate of heat flow per unit area in a SCR and is represented as θ = (T_junc-T_amb)/P_dis or Thermal Resistance = (Junction Temperature-Ambient Temperature)/Power Dissipated by Heat. Junction temperature is defined as the temperature of the junction of a SCR due to movement of charge, Ambient temperature is defined as the temperature of the surroundings of the SCR & Power Dissipated by Heat in SCR is defined as the average of the total heat generated at the junctions of the SCR due to movement of charge.

How to calculate Thermal Resistance of SCR?

The Thermal resistance of SCR formula is defined as the ratio of the temperature difference between the two faces of a material to the rate of heat flow per unit area in a SCR is calculated using Thermal Resistance = (Junction Temperature-Ambient Temperature)/Power Dissipated by Heat. To calculate Thermal Resistance of SCR, you need Junction Temperature (T_junc), Ambient Temperature (T_amb) & Power Dissipated by Heat (P_dis). With our tool, you need to enter the respective value for Junction Temperature, Ambient Temperature & Power Dissipated by Heat and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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