On this page, we will review the Analog Electronics Short Notes PDF Part 32. Welcome to Poly Notes Hub, a leading destination for analog electronics notes for engineering students.
Author Name: Arun Paul
Analog Electronics Short Notes Pdf Part 32
Here we have listed some analog electronics short notes for all types of exams like diploma engineering, degree engineering, and GATE exam and many more. In every page, we have listed 10 short analog electronics questions and answers and anyone can download it by a single click for future use.
1. What are the advantages of a TRIAC over an SCR?
A TRIAC can conduct in both directions, allowing it to control AC power more efficiently, whereas an SCR only conducts in one direction. This makes TRIACs more suitable for AC switching applications with fewer components.
2. Why is DIAC preferred to trigger a TRIAC?
A DIAC provides a sharp triggering pulse to the gate of a TRIAC at a specific voltage, ensuring reliable and symmetrical switching in both directions, which improves performance and reduces harmonics.
3. Why is power electronics so important?
Power electronics is essential for efficiently controlling and converting electric power using solid-state devices. It is widely used in industries, consumer electronics, transportation, renewable energy systems, and automation.
4. Why is DIAC used to trigger a TRIAC?
DIAC ensures that the TRIAC receives a well-defined and consistent triggering voltage, allowing smooth control of the power delivered to the load and reducing the chances of erratic or false triggering.
5. Is the name UJT appropriate?
Yes, the name Uni-Junction Transistor (UJT) is appropriate because the device contains only one PN junction and is structurally different from a bipolar junction transistor, operating mainly with unipolar conduction.
6. What is the most common application of DIAC?
The most common application of a DIAC is in light dimmers, fan speed controls, and triggering circuits for TRIACs in phase control applications.
7. What are the symptoms of a shorted DIAC or TRIAC?
A shorted DIAC or TRIAC will result in continuous conduction, even when the triggering signal is absent, leading to uncontrolled power flow to the load and possible overheating or circuit malfunction.
8. What are the symptoms of an open DIAC or TRIAC?
An open DIAC or TRIAC will fail to conduct even when triggered, resulting in no power being delivered to the load, causing the circuit to become non-functional.
9. For what are UJTs used?
UJTs are used in oscillator circuits, pulse generation, timing applications, triggering of SCRs, and as relaxation oscillators in various control systems.
10. How to turn on a DIAC in a normal way?
A DIAC turns on when the voltage across its terminals exceeds its breakover voltage (typically 30V to 40V). In normal operation, a DIAC is connected in series with a resistor-capacitor (RC) network. As the capacitor charges, the voltage across the DIAC increases. Once the voltage reaches the DIAC’s breakover point, it switches ON, conducts current, and discharges the capacitor, often into the gate of a TRIAC to trigger it. After conduction, the DIAC turns OFF when the current drops below its holding current.