5.1 State ONE effect of switch bounce in electronic circuits - NSC Electrical Technology Electronics - Question 5 - 2024 - Paper 1

Feedback occurs when a portion of the output signal is sent back to the input of the circuit, allowing the circuit to stabilize and adjust its operation based on its current state.

When the positive trigger pulse is applied, the capacitor immediately charges towards the supply voltage. This causes a rapid change in voltage across the capacitor, influencing the states of the op-amp.

Upon receiving a negative trigger pulse, the op-amp compares the voltages at its inputs. If the voltage on the non-inverting terminal becomes greater than that on the inverting terminal, the output switches state accordingly.

The output will not change if trigger pulse 2 is positive while the voltage on the inverting input remains more negative than the voltage on the non-inverting input.

The circuit in FIGURE 5.3 is identified as a monostable multivibrator.

Resistor R2 keeps pin 2 of the monostable circuit in its steady state, ensuring proper triggering.

Please refer to the provided ANSWER SHEET for the visual representation.

The circuit will reset to its resting state at 6 V when capacitor C1 charges up to two-thirds of the supply voltage, which allows the output to return to its initial condition.

The output changes state continually because both trigger pin 2 and threshold pin 6 V are connected to the top of the timing capacitor. This connection allows the circuit to repeatedly reset and trigger as the capacitor charges and discharges.

t1 and t2 are not equal because the capacitor charges and discharges through different resistors, R1 and R2, which causes different time constants.

The frequency can be calculated using the formula: f = rac{1}{T} where $T = t1 + t2$. After substituting the provided values, the frequency is approximately 7.18 Hz.

The reference voltage $V_{ref}$ is calculated to be 4.5 V using the voltage divider formula.

The resistance of R1 affects the threshold levels in the comparator circuit, thereby determining when the output changes state.

Please refer to the provided ANSWER SHEET for the visual representation.

An increase in R1 means that R1 becomes larger than R2, which will cause the voltage across R2 to decrease as more voltage drop occurs across R1.

A summing amplifier combines multiple input voltage signals into a single output voltage. It scales and sums each input according to their respective feedback resistors.

Using the formula for the summing amplifier, the output voltage $V_{out}$ is calculated as: V_{out} = -rac{R_f}{R_1} V_1 - rac{R_f}{R_2} V_2 - rac{R_f}{R_3} V_3. By substituting the given values, the output voltage is determined.

When Rf is set to 220 Ω, the gain of the amplifier becomes 1, causing the output to equal the summed inputs with a reduced scaling factor.

Please refer to the provided ANSWER SHEET for the visual representation.

During the first positive square wave, the capacitor charges up to the potential of the input while the voltage across it remains low. As the input signal goes high, the output will initially swing high as the capacitor cannot discharge quickly.

A basic circuit diagram for a passive integrator would include a resistor in series with the input signal and a capacitor to ground, creating an RC network that integrates the signal.