House Electrical Installations and EMFs
Alasdair and Jean Philips
House Wiring and EMFs
Electric and magnetic fields (EMFs) are produced as a result of the flow of electric current. The
wiring in our houses, the electric appliances and lights
EXOR GATE ( IC 7486 )
The 'Exclusive-OR' gate is a circuit which will give a high output If
either, but not both, of its two inputs are high.
An encircled plus sign
is used to show the EOR operation.
NOR GATE ( IC 7402 )
This is a NOT-OR gate which is equal to an OR gate followed by a NOT gate.
The outputs of all NOR gates are low if any of the inputs are high.
The symbol is an OR gate with a small circle on the output.
The small circle represents inv
Boolean functions may be practically implemented by using electronic gates. The
following points are important to understand.
Electronic gates require a power supply.
Gate INPUTS are driven by voltages having two nominal values, e.g. 0V and 5V
NAND GATE ( IC 7400 )
This is a NOT-AND gate which is equal to an AND gate followed by a NOT gate.
The outputs of all NAND gates are high if any of the inputs are low.
The symbol is an AND gate with a small circle on the output. The small circle represent
NOT GATE ( IC 7404)
The NOT gate is an electronic circuit that produces an inverted version of the input at its output.
It is also known as an inverter. If the input variable is A, the inverted output is known as NOT
A. This is also shown as A', or A wit
AND GATE ( IC 7408)
The AND gate is an electronic circuit that gives a high
only if all its inputs are high.
A dot (.) is used to show the AND operation
i.e. A.B. Bear in mind that this dot is sometimes omitted
What is Digital Electronics ?
Digital electronics or digital (electronic) circuits are electronics that handle digital signals discrete bands of analog levels - rather than by continuous ranges.
All levels wit