Changes

|[[File:OscilloscopeScreenDC1.png|center|140px290px]]|[[File:OscilloscopeScreenDC2.png|center|140px]]|[[File:OscilloscopeScreenDC3.png|center|140px]]|[[File:OscilloscopeScreenDC4.png|center|140px290px]]

| style="height:20px; width:140px290px; text-align:center;" |This is a constant '''direct current''' from a 3V [[battery]].| style="height:20px; width:140px290px; text-align:center;" |This is a fluctuating '''direct current'''.|-|[[File:OscilloscopeScreenDC3.png|center|290px]]|[[File:OscilloscopeScreenDC4.png|center|290px]]|-| style="height:20px; width:140px290px; text-align:center;" |This is the '''direct current''' caused by [[Mains Electricity|mains electricity]] being passed through a [[diode]].| style="height:20px; width:140px290px; text-align:center;" |This is the '''direct current''' caused by [[Mains Electricity|mains electricity]] being passed through a [[Rectifier]] which is a set of [[diodesdiode]].