Assessment Task 1 LM386 Amplifier
Assessment Task 1 LM386 Amplifier
The circuit shown above is an amplifier that can be used to replay sounds from various sources such as IPods and MP3 players. The circuit can also be used to mix sounds from various sources and this could provide a good extension task for those students that complete the assessment task early. The circuit will be powered via a 9 volts battery but once again could be modified to run off the mains.
Instructions
- Use data sheets for the LM386 operational amplifier
- Design the circuit using DIYLC software, this circuit is to be manufactured on strip-board
- Add a switch and an LED power indicator (not shown in schematic)
- Check your design against the schematic and secure approval to proceed with the manufacturing phase from the lecturer
- Manufacture the completed design, drill the circuit board and gather the required components
- Populate and solder components to the circuit board using safe soldering techniques
- Once complete visually check the circuit board for defects, crossed tracks and dry joints
- Use test equipment as directed to confirm the correct function of your circuit and components
Component List:
- 9 Volt Battery and Battery Holder
- LM386 Amplifier
- 1 x 50 nf and 1 x 100 nF ceramic Capacitors
- 1 x 100 uF, 1 x 10 uF and 1 x 220 uF Electrolytic Capacitors
- 1 x 10k Potentiometers
- 1 x LED (power indicator)
- 1 x 470 Ω (for power indicator LED) , 1 x 10 Ω resistors
- 1 x Switch
- 1 x 0.3 Watt Speaker
- Various Cables and Connectors
Task 1
Draw or print and attach the pin-out diagram for LM386 Operational Amplifier
LM386 Op AmpSigned Lecturer …………………………………………….
Date ……………………………………………
Task 2
Include a circuit plan of either
Signed Lecturer …………………………………………….
Date …………………………………………
Task 3
Tick off each of the components used in this circuit against the items on the following list. I have completedone for you
Item / Used in circuit1 / Item / Used in circuit1Fixed Resistors / Analogue/Digital IC’s
Variable Resistors / Surface Mount Packages
Potentiometers / 10k / Rectifiers
Sensing Resistors (LDR etc) / Switches
Fixed Capacitors / Mini Transformers
Electrolytic Capacitors / Decoders
Diodes / Regulators
Zener Diodes / Encoders or Resolvers
Light Emitting Diodes (LED) / Inverters or Servo Controllers
Transistors / Edge Connectors
Thyristors / Wiring/pins/tags/wire links
Fixing Spacers / Small Heat Sinks
Insulators / Cables
Cable Connectors / Opto-Electronic Components
Protection Devices
Signed Lecturer …………………………………………….
Date ……………………………………………
Task 4
Assemble the circuit and tick off the tools used to make this circuit from the following list
Item / ItemHeat shunts/tweezers / Component forming devices
Snipe nosed pliers / Wire Strippers
Sleeving pliers / Side or end cutters
Bolt fasteners (spanners) / Specialized assembly equip
Anti-static mats or straps
Briefly describe the procedure and tools you used to make this circuit using the box below
Signed Lecturer …………………………………………….
Date ……………………………………………
Task 5
From the following list tick off which functions you think this circuit fulfils. Once again I have given you an example, the 555 timer functions as an oscillator.
Circuit / Component function / Circuit / ComponentFunction
Audio amplifier / LM386 / Filter
Signal converter / Microprocessor application
Signal generator / Comparator
Counter/Timer / Power amplifier
Oscillator / Motor control
Regulated power supply / Sensor/actuator circuit
Logic function controls / ADC/DAC hybrid circuit
Display Circuit / Alarm/protection circuit
Use a schematic of the circuit to highlight (circle) which components function as the circuits you have ticked off on the list above. Staple the completed schematic to this page.
Signed Lecturer …………………………………………….
Date ……………………………………………
Task 6
Test / Equipment / ResultThe resistance between power and ground / Multimeter
The earth continuity / Multimeter
The continuity of the power line / Multimeter
The voltage levels at the power pins for both the LM358 and the LM386 / Multimeter
The signal at the input and output of the circuit / Oscilloscope
Multimeter
Bench Power Supply
Function Generator
Signed Lecturer …………………………………………….
Date ……………………………………………
Task 7
Use the box below to briefly evaluate this exercise, stating the things you have learned whilst building the circuit, how you overcame any problems you encountered and what if anything you would do differently next time.
EvaluationSigned Lecturer …………………………………………….
Date ……………………………………………
Practical Observation
TaskThe student carried out the following tasks: / Competent
Yes / No
Designed the circuit using DIYLC
Correctly identified the correct components to manufacture the circuit using the schematic and data sheets/charts
Was able to follow the circuit plan and successfully populate the board
Correctly identified polarity dependant components
Safely soldered the components to the stripboard and carried out a visual check of the soldering
Carried out a visual check on all components for signs of damage, carried out a ‘pull test’ on components to check for faulty soldering
Adhered to safety regulations at all times when manufacturing the amplifier circuit, including the use of correct PPE
Connect test equipment to the circuit in a safe and approved manner
Demonstrated the use of test equipment to test circuit function and trace circuit faults in a safe manner
Left the workspace in a safe and tidy condition when work was completed
Assessor Feedback
Signed Lecturer …………………………………………….
Date ……………………………………………
Student Declaration
All of the work included as a part of this assessment is my own:
Task 1: Signed Student……………………………………….
Date……………………………………………
Task 2: Signed Student……………………………………….
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Task 3: Signed Student……………………………………….
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Task 4: Signed Student……………………………………….
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Task 5: Signed Student……………………………………….
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Task 6: Signed Student……………………………………….
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Task 7: Signed Student……………………………………….
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All tasks complete
Signed Lecturer …………………………………………….
Date ……………………………………………