Embedded Files
Operational Amplifiers (Op-Amp) have two inputs and one output and are commonly made as DIL (Dual In Line) integrated circuits.
A common type is a TL072 op-amp which is in an 8 pin Integrated Circuit (IC) containing two separate amplifiers as shown in Fig 1.
A common type is a TL072 op-amp which is in an 8 pin Integrated Circuit (IC) containing two separate amplifiers as shown in Fig 1.
The two inputs are known as the inverting and non-inverting inputs.
The arrangement, (Fig 2) shows the numbered legs of the IC related to the circuit diagram:
The arrangement, (Fig 2) shows the numbered legs of the IC related to the circuit diagram:
This circuit (Fig 3 and Fig 4) uses the Op-Amp as a comparator. This means that the circuit compares the non-inverting input with the inverting input and gives a high or low response. This is also known as a differential amplifier.
This circuit uses a Light Dependent Resistor (LDR), but these can be replaced with other types of sensors if required.
By changing the Variable Resistor you can alter the sensitivity of the circuit.
What do you notice about the output from this circuit? How can you alter it?
This circuit uses a Light Dependent Resistor (LDR), but these can be replaced with other types of sensors if required.
By changing the Variable Resistor you can alter the sensitivity of the circuit.
What do you notice about the output from this circuit? How can you alter it?
In addition to a Prototype board (Breadboard), wire for connections and a power source, you will need the following components to build this circuit:
1 x 1MΩ Fixed Resistor1 x 100KΩ Fixed Resistor1 x 220Ω Fixed Resistor1 x 100KΩ Preset Potentiometer1 x miniature LDR1 x TL072 Operational Amplifier IC (Data Sheet)1 x LED
1 x 1MΩ Fixed Resistor1 x 100KΩ Fixed Resistor1 x 220Ω Fixed Resistor1 x 100KΩ Preset Potentiometer1 x miniature LDR1 x TL072 Operational Amplifier IC (Data Sheet)1 x LED
Fig 4
TL071
Page updated
Report abuse