You have not been working long in a small Electronic Engineering business when your boss (an engineer in his own right) hands you two sheets of paper each with a circuit roughly sketched on it, tasking you with building, testing and checking their functionality. The first circuit has a power supply regulator function for you to confirm with measurements, and the second is a sequence for output to some automation equipment.
Build both circuits and do the tests required, as follows:
Task 1 ~
For circuit (1) –
You have been told that this circuit is to be for a power supply that has a variable output range that should include 5V – 12V at an output maximum load current of 200mA.
Do some circuit analysis calculations to check the design first and make any adjustments to values you deem necessary.
Next, build and test the circuit, taking measurements to confirm its performance
Record d.c. voltage measurements at points A and output Vo for the extreme settings of the potentiometer, and then using the a.c. range on your multimeter take measurements again at A and Vo (also for both extreme settings). Do these tests with an output load current of about 50mA and again at about 200mA.Tabulate your results.
Summarise the performance, observations and recommendations into a short report. The recommendations should include suggestions for improvements.
Task 2 ~
For circuit (2) –
You have been informed that the sequencer circuit requires verification. To do this you will :
Study the datasheet for the 4017 IC (and the datasheet for the LM555)
Do some preliminary calculations to verify the LED drive circuit and the timer (555) circuit. Determine that there is sufficient current to light the LED when on and calculate the timing information for the timer (555) circuit.
Briefly explain the operation of the circuit
Build the circuit and once checked, connect to a 9V power source (either the PSU circuit from Task 1 or a 9V battery)
By monitoring the d.c. voltage at point A on circuit 2 and noting the changes in voltage, count the changes over a 20sec interval to determine the timing from the timer. Record your observations and results.
Investigate that the two switches behave correctly (simulate switches by using wire links).
Record the timing sequence and periods for the LED at the output (B).
Describe step by step the operation of the circuit and comment on the performance, and any observations and recommendations into a short report.