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Refer to FIGURE 2.2 below and answer the questions that follow - NSC Electrical Technology Digital - Question 2 - 2019 - Paper 1
Question 2
Refer to FIGURE 2.2 below and answer the questions that follow. 1. State the function of R1 and R2. 2. Describe what happens when the set switch, S1, is pressed. 3.... show full transcript
Worked Solution & Example Answer:Refer to FIGURE 2.2 below and answer the questions that follow - NSC Electrical Technology Digital - Question 2 - 2019 - Paper 1
Step 1
State the function of R1 and R2.
Answer
The resistors R1 and R2 are used as pull-up resistors in the bistable multivibrator circuit. They help determine the threshold levels for the output by controlling the charge and discharge rates of the capacitor and ensuring stable operation of the flip-flop.
Step 2
Describe what happens when the set switch, S1, is pressed.
Answer
When the set switch S1 is pressed, threshold pin 2 of the 555 timer is pulled low. This causes the output of the timer to switch high, turning on the LED. The output state remains high until the reset switch is pressed or the circuit is powered off, thus setting the multivibrator in its 'set' state.
Step 3
Explain why threshold pin 6 is connected directly to ground.
Answer
Threshold pin 6 is connected directly to ground to ensure that when the output is low, the 555 timer is reset properly. This configuration helps in defining the reference point for the voltage levels in the bistable mode, allowing for stable switching between high and low states.