Mechatronics Flashcards
Define transistors, - how do they work and what are they used for? What parts are the transistors made up of?
Transistors are very important for digital systems. Transistors give signals that determine whether current should flow or not. Transistors have the connector, emittor and the base. Current flows from connector to emittor or vise versa and the signal of whether to flow or not comes from the base.
Can you convert natural numbers (with base 10) to binary numbers and vice versa? try with base 16.
do 420 to binary. do 110011 to number system and 5673 to base 16.
sure. why not.
Do you know the truth tables of AND, OR, XOR and NOR gates? What about the notations?
See notes.
Transistor also work as amplifiers and negating signals yh? What’s the equation for that.
See notes.
Describe what a buffer amplifier/unity gain amplifier does and how does it work? What’s the formula?
It’s very important to connect circuits without changing the signals of each other’s circuits. So buffer amplifiers allow for that. + they can also amplify.
Vout = Vin x (1 +R2/R1) - see notes for the diagram. It changes for each law.
What theory does the strain gauge use?
Usually used on beams. As length of the strain gauge changes, so will the resistance. Based of the change in resistance you can find the change in length - hence the strain. However, the change in length is very small and so the change in resistance as well, so the signals are usually amplified. You later process the signal with strain gauge specifications.
What is the wheatstone bridge used for?
To get the change in resistance of the strain gauge. It allows us to see the small change in resistor as a change in voltage, but amplified.
What are inverting amplifier, non-inverting amplifier and difference amplifier. Where is the difference amplifier used?
They’re all amplifiers but have different equations. You should know how they work. See the diagrams in the worksheet. A non-inverting amplifier just amplifies a signal. The eqn is Vout = (1 + R2/R1 ) Vin.
An inverting amplifier not only amplifies but ‘inverts’ the signal. Makes it a minus. Vout = - (Rf/Rin ) Vin.
A difference amplifier’s amplification is proprtional to the difference in the two resistances. Vout = Rf/R1 (V2 - V1)
Since a difference amplifier amplifies the difference in voltage. it is used in strain gauges. It is paired with a wheatstone bridge - which gives a voltage difference but wayy too small, so it needs to be amplified.
