FYP 2 Week 1 – Research & Simulation of Voltage Comparator & AC-DC converter

Voltage Comparator circuits:

In this project, the super capacitor bank will be fully charged to 5.4V. To check whether the super capacitor bank are fully charged or not, a voltage comparator circuit are used.

Proteus (ISIS) simulation software was used to do simulation.

Voltage Comparator IC LM293 (not functioning) in simulation shows error stating that no specified model for that particular IC in simulation software.

Since the voltage comparator IC LM293 does not functioning in simulation, it was then replaced with voltage comparator IC CA3140. Following that, the circuits function as required.

Voltage Comparator IC CA3140 (functioning) in simulation will detect input voltage of less than 5.09V:

• Figure showing input voltage detected less than 5.09V and light up Red LED.

Voltage Comparator IC CA3140 (functioning) in simulation will detect input voltage of more than 5.09V:

• Figure showing input voltage detected more than 5.09V and light up Green LED.

AC-DC converter:

The power generate from the dynamo will enter the AC-DC converter that will convert AC power from dynamo into DC power. The AC-DC converter consists of bridge rectifier, capacitor filters, and voltage regulator IC.

• Simulation of AC – DC converter circuit.

Simulation for AC-DC converter circuit was done by connecting its output to an oscilloscope and the output result was verified by analysing the voltage waveform result displayed on the oscilloscope as shown in figure below. The waveform voltage output on channel A is directly taken from the AC supply. While voltage output on channel D is the final DC voltage output from the converter circuits. The reading of the DC voltage output on channel D was read at the smallest scale of the oscilloscope which is 5mV/Division compare to the reading on channel A which read at 5V/Division. This shows that the DC voltage output produced is very stable as the result of using 0.1F capacitor as the filter. When tested with capacitor filter of lower value (10uF-47uF) that commonly used, the DC output was not as stable as of using the 0.1F values. Thus, this proves the circuits met its functionality.

Figure of simulation result of AC – DC converter circuit.