Microelectronic Control Systems

What Microelectronic Control Systems covers

Microelectronic Control Systems is examined in Unit A2 1: Option A, Electronic and Microelectronic Control Systems, one option of three. It covers microcontroller systems, ADCs and DACs, strain gauges and bridge circuits, optical switches, encoded discs and Schmitt triggers, op-amp amplifiers and gain, Zener diodes and voltage regulators, Karnaugh maps and binary counters, seven-segment, LCD and dot matrix displays, PIC flowcharts and programming and DC motors, stepper motors and driver circuits.

The 9 subtopics

Each one has its own page.

• Microcontroller systems, ADCs and DACsPICs as input, process and output, closed loop temperature control and hysteresis, feedback, anti-static handling, ADC step size and readings, DACs and sampling rate.Open →
• Strain gauges and bridge circuitsStrain gauges, their alignment and uses, the Wheatstone bridge and its balance condition with worked outputs, dummy gauges, differential amplifiers and loading a divider.Open →
• Optical switches, encoded discs and Schmitt triggersPhototransistors, slotted and reflective optical switches, encoded discs and Gray code, binary coded decimal, position sensors and Schmitt triggers with hysteresis.Open →
• Op-amp amplifiers and gainIdeal op-amps and negative feedback, inverting, non-inverting, differential and summing amplifiers with worked gains, saturation, voltage followers and comparators.Open →
• Zener diodes and voltage regulatorsRegulated supplies, Zener diode regulators and series resistor calculations, power ratings, 7805 and 7812 regulators and their dissipation, decoupling capacitors and low-dropout regulators.Open →
• Karnaugh maps and binary countersKarnaugh maps and grouping rules with worked simplifications, binary and BCD counters, edge triggering, frequency division, counting to five, and switch bounce.Open →
• Seven-segment, LCD and dot matrix displaysSeven-segment labelling, common anode and cathode displays, decoders, multiplexing, LED bar arrays, LCD modules and dot matrix displays.Open →
• PIC flowcharts and programmingFlowchart symbols, loops and delays, incrementing and counting, a car park program, subroutines, interrupts against polling, setting outputs in binary, simulation and debouncing.Open →
• DC motors, stepper motors and driver circuitsDC motor characteristics and speed control, stepper motors with worked step and speed calculations, holding torque, driver ICs such as the ULN2803, H-bridges and motor supplies.Open →

What you need to know

Answer each one before you reveal it.

Take Microelectronic Control Systems further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Binary code vs Gray code

  Binary code: a counting sequence in which several bits may change between neighbouring values. Gray code: a sequence in which exactly one bit changes between neighbouring values.

• Common anode display vs Common cathode display

  Common anode display: a seven-segment unit whose segments light when their pins are pulled to logic 0. Common cathode display: a seven-segment unit whose segments light when their pins are driven to logic 1.

• Inverting amplifier vs Non-inverting amplifier

  Inverting amplifier: an op-amp stage with gain −Rf ÷ Rin whose output is opposite in sign to its input. Non-inverting amplifier: an op-amp stage with gain 1 + Rf ÷ R₁ whose output is in phase with its input.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What is a PIC?

   Model answer

   A PIC, or peripheral interface controller, is a microcontroller: a small computer on a single chip. A PIC holds a processor, program memory, data memory and input/output pins.

2. 2

   How does a PIC-based control system map onto input, process and output?

   Model answer

   Sensors and switches connect to the PIC's input pins. The program is the process, and the output pins drive devices through interface circuits.

3. 3

   Compare a PIC with digital I/O only and one with mixed digital and analogue I/O.

   Model answer

   A digital-only PIC reads just logic 0 or 1 on each input pin. A mixed I/O PIC also has analogue inputs feeding a built-in ADC, so it can read sensor voltages directly.

4. 4

   Name a commonly used PIC with digital I/O only and one with analogue inputs.

   Model answer

   The PIC16F84A has digital input and output pins only. The PIC16F88 adds analogue inputs through a built-in 10-bit ADC.

5. 5

   Explain how a PIC can provide closed loop temperature control.

   Model answer

   A thermistor divider feeds an analogue input, and the program compares the reading with a set value. The PIC switches the heater on below the set value and off above it.

6. 6

   Why does on/off control with a single set point cause rapid switching, and how can a program prevent it?

   Model answer

   Small fluctuations around one set point switch the output on and off repeatedly. A program can use two set points a little apart, so the output changes only when clearly needed.

What is inside Levo

Six ways to work the same material.

Microelectronic Control Systems revision questions

What does Microelectronic Control Systems cover in CCEA A-Level Technology and Design?

9 subtopics: microcontroller systems, adcs and dacs, strain gauges and bridge circuits, optical switches, encoded discs and schmitt triggers, op-amp amplifiers and gain, zener diodes and voltage regulators, karnaugh maps and binary counters, seven-segment, lcd and dot matrix displays, pic flowcharts and programming and dc motors, stepper motors and driver circuits. Each one has its own page with questions and model answers.

How is Microelectronic Control Systems organised?

By the CCEA 8900 specification, subtopic by subtopic, so it matches the order you are taught it in.