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## Intrinsic stand-off ratio for UJT based Thyristor firing circuit Solution

STEP 0: Pre-Calculation Summary
Formula Used
UJT intrinsic standoff ratio = Emitter resistance base 1/(Emitter resistance base 1+Emitter resistance base 2)
η = RB1/(RB1+RB2)
This formula uses 2 Variables
Variables Used
Emitter resistance base 1 - Emitter resistance base 1 is the resistance offered to the current flowing through the base 1 junction on UJT. (Measured in Ohm)
Emitter resistance base 2 - Emitter resistance base 2 is the resistance offered to the current flowing through the base 2 junction on UJT. (Measured in Ohm)
STEP 1: Convert Input(s) to Base Unit
Emitter resistance base 1: 10 Ohm --> 10 Ohm No Conversion Required
Emitter resistance base 2: 5 Ohm --> 5 Ohm No Conversion Required
STEP 2: Evaluate Formula
Substituting Input Values in Formula
η = RB1/(RB1+RB2) --> 10/(10+5)
Evaluating ... ...
η = 0.666666666666667
STEP 3: Convert Result to Output's Unit
0.666666666666667 --> No Conversion Required
0.666666666666667 <-- UJT intrinsic standoff ratio
(Calculation completed in 00.000 seconds)

## < 10+ Thyristors Calculators

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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
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Power dissipated by heat in SCR
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Thermal resistance of SCR
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Leakage current of the collector-base junction
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Discharging current of dv/dt protection thyristor circuits
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### Intrinsic stand-off ratio for UJT based Thyristor firing circuit Formula

UJT intrinsic standoff ratio = Emitter resistance base 1/(Emitter resistance base 1+Emitter resistance base 2)
η = RB1/(RB1+RB2)

## What is intrinsic stand-off ratio in UJT firing circuit?

For a unijunction transistor, the resistive ratio of RB1 to RBB is called the intrinsic stand-off ratio and is given the Greek symbol: η (eta). Typical standard values of η range from 0.5 to 0.8 for most common UJT’s.

If a small positive input voltage which is less than the voltage developed across resistance, RB1 ( ηVBB ) is now applied to the Emitter input terminal, the diode p-n junction is reverse biased, thus offering a very high impedance and the device does not conduct. The UJT is switched “OFF” and zero current flows.

## How to Calculate Intrinsic stand-off ratio for UJT based Thyristor firing circuit?

Intrinsic stand-off ratio for UJT based Thyristor firing circuit calculator uses UJT intrinsic standoff ratio = Emitter resistance base 1/(Emitter resistance base 1+Emitter resistance base 2) to calculate the UJT intrinsic standoff ratio, The Intrinsic stand-off ratio for UJT based Thyristor firing circuit formula is defined as the ratio of emitter base 1 resistance to the total emitter base junctions resistances. UJT intrinsic standoff ratio is denoted by η symbol.

How to calculate Intrinsic stand-off ratio for UJT based Thyristor firing circuit using this online calculator? To use this online calculator for Intrinsic stand-off ratio for UJT based Thyristor firing circuit, enter Emitter resistance base 1 (RB1) & Emitter resistance base 2 (RB2) and hit the calculate button. Here is how the Intrinsic stand-off ratio for UJT based Thyristor firing circuit calculation can be explained with given input values -> 0.666667 = 10/(10+5).

### FAQ

What is Intrinsic stand-off ratio for UJT based Thyristor firing circuit?
The Intrinsic stand-off ratio for UJT based Thyristor firing circuit formula is defined as the ratio of emitter base 1 resistance to the total emitter base junctions resistances and is represented as η = RB1/(RB1+RB2) or UJT intrinsic standoff ratio = Emitter resistance base 1/(Emitter resistance base 1+Emitter resistance base 2). Emitter resistance base 1 is the resistance offered to the current flowing through the base 1 junction on UJT & Emitter resistance base 2 is the resistance offered to the current flowing through the base 2 junction on UJT.
How to calculate Intrinsic stand-off ratio for UJT based Thyristor firing circuit?
The Intrinsic stand-off ratio for UJT based Thyristor firing circuit formula is defined as the ratio of emitter base 1 resistance to the total emitter base junctions resistances is calculated using UJT intrinsic standoff ratio = Emitter resistance base 1/(Emitter resistance base 1+Emitter resistance base 2). To calculate Intrinsic stand-off ratio for UJT based Thyristor firing circuit, you need Emitter resistance base 1 (RB1) & Emitter resistance base 2 (RB2). With our tool, you need to enter the respective value for Emitter resistance base 1 & Emitter resistance base 2 and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well. Let Others Know