Summing Amplifier

A summing amplifier is an adaptation of the inverting amplifier in which the output voltage is the result of summing the results due to each separate input signal – hence the name. This is a useful circuit which combines a number of separate signals together,...

Op-amp Assumptions

An idealised operational amplifier is assumed to have a number of properties such as infinite gain, infinite input impedance, zero output impedance and infinite bandwidth. Real-world op-amps have properties which only approximate towards these ideals, but use of these...

Combinational Logic Circuits

In a combinational logic circuit, the output depends only on the current state or ‘combination’ of inputs. The behaviour of this type of system may be defined using a truth table, or a Boolean expression. Combinational logic systems range in complexity...

Bar Graph Display

An electronic bar graph display uses a series of LEDs to indicate an analogue property, such as a sound level or electrical charge value. In some applications, it may be appropriate to use different colour LEDs to indicate high and low values. As with individual LEDs,...