‘Passive’ refers to the fact that this type of filter is incapable of power gain and uses no active components. This also means that no external power source is needed for it to function.
A high-pass filter, as the name suggests, allows high frequencies to pass whilst cutting off lower frequencies. The cut-off frequency (Fc), is calculated by using the formula below. ‘R’ is the resistor value, and ‘C’ is the capacitor value.
The XNOR gate is an inverted XOR gate. The out put is only true when either all the inputs are false, or all the inputs are true. It is effectively an XOR gate in series with a NOT gate.
A NOR gate simply produces a true output only when all of the inputs are false. It is effectively just an OR gate in series with a NOT gate.
Exclusive OR (XOR) gates operate on the same logic as an OR gate excluding one difference. If more than one of the inputs is true, then the output will be false.
In order for the output to be true, only one of the inputs can be true.
A NAND gate is an AND gate whose output has been inverted. This effectively means that unless all inputs are true, the output will be true.
A NOT gate (Inverter), is a single input logic gate. The output is simply opposite to that of the input.
You can simply create a NOT gate by using an NPN transistor and two resistors as shown here: ‘https://thelectronicsblog.wordpress.com/2015/11/29/not-gate-using-a-transistor’
An OR gate only requires one inputs to be true for the output to be true. All inputs need to be false for the output to be false.
An AND gate requires all inputs to be true for the output to be true. Any other combination results in the output being false.
Light Emitting Diodes (LEDs) are semiconductors that emit light when a current is applied to them. They are comparatively much more energy efficient, when compared to lighting alternatives (E.g filament bulbs), but are generally considerably more expensive.
As with any other didode, LEDs have an anode and a cathode. However, the reverse breakdown voltage is much lower. In addition to this, a resistor is needed in series, in order to limit the rate at which current flows through the LED.
Breadboard is used to prototype new circuits. It consists of a plastic housing with holes used to thread wire/components into. the holes are connected in lines by conductive material to adjacent holes. The diagram below shows which holes are connected to each other and how a breadboard is generally laid out (the green lines represent the conductive material).