CASA B1-04 Electronic Fundamentals

These flashcards cover various electronic fundamentals, including diodes, transistors, operational amplifiers, and circuit design principles essential for your upcoming examination.

What type of device allows current to flow in one direction but opposes it in the opposite direction?

Diode

What is the barrier potential for silicon diodes typically?

0.7 V

What is the function of a diode in an electronic circuit?

To allow current flow in one direction while blocking it in the opposite direction.

What does LED stand for?

Light Emitting Diode

What semiconductor materials are commonly used to make LEDs?

Gallium arsenide, gallium arsenide phosphide, gallium phosphide.

What happens to the depletion region when a diode is forward biased?

The depletion region narrows.

What is an SCR and what does it stand for?

Silicon Controlled Rectifier, used to control power flow.

What is the primary use of a rectifier diode?

To convert AC voltage to DC voltage.

What does RTH stand for in the context of capacitive sensors?

Resistance to Humidity and Temperature.

In terms of diodes, what does reverse bias mean?

A condition that prevents current from flowing through the diode.

What is the difference between an NPN and a PNP transistor?

NPN has an N-type material on both ends with P-type in the middle; PNP reverses this arrangement.

How does the characteristic curve of a real diode differ from an ideal diode?

A real diode has a voltage drop and resistance when forward biased.

What do the terms 'enhancement mode' and 'depletion mode' refer to in FETs?

Modes of operation for Field Effect Transistors, where enhancement mode increases conductivity and depletion mode reduces it.

What are transistors primarily used for in electronic circuits?

To amplify or switch electronic signals.

What is the purpose of operational amplifiers in circuits?

To amplify voltage signals.

What are the two types of integrated circuits mentioned?

Linear integrated circuits; Logic integrated circuits.

What is the difference between an open-loop and a closed-loop control system?

An open-loop system operates independently of the output, while a closed-loop system uses feedback to adjust it.

What device converts mechanical energy into electrical energy?

Transducer.

What is the primary function of a photoconductive diode?

To allow current in reverse bias when exposed to light.

What does a Zener diode do in reverse breakdown?

It maintains a constant voltage.

How is the voltage across a Zener diode characterized?

It remains almost constant despite changes in current.

What role do inductance transmitters have in electronic circuits?

To measure position based on inductance changes.

What is the purpose of a servomechanism?

To use feedback to control mechanisms automatically.

What is the function of a differential synchro in a control system?

To transmit signals that represent the difference between two input conditions.

What defines a linear variable differential transformer (LVDT)?

It converts linear motion into an AC signal.

What is meant by the term 'microelectronics'?

The use of integrated circuits to miniaturize electronic equipment.

In a transistor, what does the term gain refer to?

It is the ratio of output current to input current.

What is a key disadvantage of open-loop control systems?

They do not correct errors automatically.

What type of circuit does a bridge rectifier provide?

Full-wave rectification.

What types of feedback are generally used in control systems?

Positive feedback and negative feedback.

What happens to the forward current when the forward voltage across the diode exceeds the barrier potential?

The forward current increases rapidly.

What parameter is critical for proper operation of a transistor amplifier?

The biasing of the Base-Emitter junction.

What is an organic LED and its advantage?

A flexible thin-film light emitting diode, known for its energy efficiency and flexibility.

How do you check a diode's functionality using a digital multimeter?

By testing its forward and reverse bias conditions.

What is a characteristic of a single-sided PCB compared to a double-sided PCB?

Single-sided PCB has components mounted on one side, while double-sided has components on both sides.

Define the term 'torque synchro'.

A type of synchro that uses current in the rotors to generate torque to move the load.

What do variable resistors such as potentiometers do?

They change resistance and thereby control current.

What does a capacitive sensor do?

It converts mechanical movements to electrical signals by varying capacitance.

What key performance measure is often used for measuring the accuracy of position sensing systems in aircraft?

Accuracy of ±0.5%.

What leads to dynamic resistance in a diode?

The change in resistance along the V-I curve depending on the current levels.

What does the term 'feedback' refer to in a control system?

It is the process of using the actual output to adjust the input for achieving desired results.

What is the primary voltage for Zener diodes?

Typically between 1.2V to 200V.

What circuit element is a photoresistor similar to?

A photoconductive diode.

Define 'magnitude' in the context of the position sensors.

The extent or amount of movement based on varying physical conditions.

What are the key characteristics of an operational amplifier?

High voltage gain, high input impedance, low output impedance.

What is the relationship between current and voltage in a diode when it is operating under forward bias?

An increase in voltage results in a proportional increase in current.

Explain the significance of 'zero error' in control systems.

It indicates that the system output matches the desired output, no corrective action needed.

What type of components are hall sensors designed to detect?

Magnetic fields for measurement or control.

What do servomechanisms automatically control in an aircraft?

Control surfaces such as ailerons and elevators.

What happens to the output of a servomechanism when there is a disturbance?

The system will self-correct to reach the desired output position.

What is the significance of the feedback loop in a closed-loop servomechanism?

It provides real-time correction based on output.

What is the importance of using sharing resistors in parallel connected diodes?

To equally distribute current and voltage across multiple diodes.

How is the leakage current in diodes described?

It is the small reverse current that flows when a diode is reverse biased.

What is an example of an application using operational amplifiers?

Signal conditioning in sensors.

When testing a diode, what voltage is typical for reverse bias tests?

2.5V to 2.6V.

What adjustments do you make to ensure a transistor provides useful power amplification?

Correctly bias the base-emitter junction.

How does a multi-layer PCB differ from a double-sided board?

It has multiple layers of insulating and conducting materials.

What tests can be performed to diagnose LED failures?

Forward bias testing and reverse bias testing.

What component is needed to check reverse bias in a photoconductive diode?

Digital multimeter.

What can be inferred from the output voltage of an op-amp in a negative feedback circuit?

It stabilizes the output to track the input closely.

What is a main function of operational amplifiers?

To amplify weak signals.

What does PWM stand for in terms of control systems?

Pulse Width Modulation.

What indicates the operational status of a BJT transistor?

The relationship of VBE to VCE.

What is meant by the term 'negative feedback' in op-amps?

A portion of the output is fed back to the input to stabilize the output.

What occurs when a Zener diode reaches its breakdown voltage?

It conducts in reverse without damage.

What do differential transmitters measure?

The difference between two input signals.

What is a key advantage of using a tonal synchro in an aircraft control system?

Fast and accurate positional feedback transmission.

What function do torque synchro systems serve?

To transmit position data from one point to another.

What is the primary role of a rectifier diode in power supplies?

To convert AC to DC.

What does a capacitor in a circuit typically store?

Electrical energy.

What type of output do digital transducers provide?

Discrete signals indicating position or status.

In an operational amplifier circuit, what is the effect of equal resistor values on gain?

The gain remains linear relative to input voltage.

What principle does a transducer operate on?

Converting one form of energy into another.

What advantage do multi-layer PCBs provide in complex circuits?

Increased conductor surface area and reduced space.

What is the function of inductance in an inductance transmitter?

To measure magnetic field response changes.

Why is the static friction in torque systems significant?

It reduces operational accuracy.

What determines the output voltage in an LVDT?

The position of the armature relative to the windings.

What is the significance of operational amplifiers in analog signal processing?

They perform amplification and signal conditioning.

What happens to the current in an ideal diode during reverse bias?

It should theoretically remain at zero.

What is an application of through-hole technology in PCBs?

Mounting larger components securely.

In which biasing condition will a diode conduct current?

When it is forward biased.

What type of voltage is used in capacitance sensing systems?

Alternating current (AC) to vary capacitance.

How does a bridge rectifier enhance the efficiency of a rectification circuit?

It allows the full AC wave to be efficiently converted to DC.

How are the weights compared in a strain gauge transducer?

Through resistance changes caused by applied loads.

What is an application where PID control is essential?

In automatic temperature regulation systems.

What are the two primary categories of servo control?

Position control and speed control.

What is the role of thermal coupling in photoconductive devices?

To detect changes in light intensity.

What component represents a high-precision, low-drift feedback control element?

Operational amplifiers.

What is the core functionality of a varistor in electronic circuits?

To protect against voltage spikes.

What does the term 'follow-up' refer to in servomechanisms?

Corrective actions taken to stabilize a system after disturbance.