Frequency of UJT as Oscillator Thyristor Firing Circuit Calculator

Formula Used:

\[ f = \frac{1}{R_{stb} \times C \times \ln\left(\frac{1}{1-\eta}\right)} \]

Frequency (f):

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1. What is Frequency of UJT as Oscillator Thyristor Firing Circuit?

The Frequency of UJT as Oscillator in Thyristor Firing Circuit refers to the oscillation frequency generated by a Unijunction Transistor (UJT) based relaxation oscillator used for triggering thyristors in power control applications.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ f = \frac{1}{R_{stb} \times C \times \ln\left(\frac{1}{1-\eta}\right)} \]

Where:

\( f \) — Frequency (Hz)
\( R_{stb} \) — Stablizing Resistance (Ω)
\( C \) — Capacitance (F)
\( \eta \) — Intrinsic Stand-off Ratio

Explanation: The formula calculates the oscillation frequency based on the circuit's stabilizing resistance, capacitance, and the UJT's intrinsic stand-off ratio.

3. Importance of Frequency Calculation

Details: Accurate frequency calculation is crucial for proper thyristor firing timing, power control precision, and ensuring stable operation of power electronic circuits.

4. Using the Calculator

Tips: Enter stabilizing resistance in ohms, capacitance in farads, and intrinsic stand-off ratio (between 0 and 1). All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range of intrinsic stand-off ratio?
A: The intrinsic stand-off ratio typically ranges from 0.5 to 0.8 for most UJTs.

Q2: How does capacitance affect the frequency?
A: Higher capacitance values result in lower oscillation frequencies, while lower capacitance values produce higher frequencies.

Q3: What is the purpose of the stabilizing resistance?
A: The stabilizing resistance helps maintain stable oscillation and prevents latch-up in the UJT circuit.

Q4: Can this calculator be used for different UJT types?
A: Yes, as long as the intrinsic stand-off ratio is known for the specific UJT type.

Q5: What are typical applications of UJT oscillators?
A: UJT oscillators are commonly used in thyristor firing circuits, timing circuits, and pulse generation applications.