Unit c electrical principals & technologies notes(parallel & series ciruit)

1. Parallel vs Series Circuits

2. Series Circuits
 Series Circuit:
 The circuit in which the current passes through each bulb in turn
 Only 1 pathway for the current
 If that pathway is interrupted, the whole circuit cannot function.
 Adding components increases the total resistance of the circuit. This
decreases the current. Thus, adding an extra bulb to a series string of
lights makes all the bulbs dimmer.

3. Series Circuits
 Series Circuit:
 However, series circuits do have
an important use. In household
circuits, switches are wired in
series with other components (e.g.,
wall plugs, lights). This makes it
possible to turn off all the
electricity in the circuit.

4. Parallel Circuits
 Parallel Circuit:
 Has a separate current path for each section of the circuit
 An interruption or break in one pathway does not affect the rest of
the pathways in the circuit.
 Adding a new pathway with more resistors does not affect the
resistance in any of the other pathways.

5. Parallel Circuits
 Parallel Circuit:
 In a parallel-wired string of lights, for
example, each bulb has its own path to the
current source.
 adding extra resistors in parallel decreases the
total resistance of the circuit. This might seem
strange, but remember that adding more paths
for the current to take means less total
resistance. Think about how much less
resistance there is when you drink through two
straws instead of one.

6. Parallel Circuits

7. Series vs Parallel Circuits
 Think of String or Christmas
Lights! Do we want them in a
series circuit of parallel
circuit?
 Parallel! If one burns out the
rest won’t go out

8. Series vs Parallel Circuits

9. Series vs Parallel Circuits
 Household wiring, Series or parallel?
 Household wiring is one of many applications that use parallel circuits.
You wouldn’t want the power to your refrigerator to go off if a bulb
burnt out, would you?

10. Series vs Parallel Circuits
 Transistor:
 used for tiny circuits, referred to as solid-state
components because they are made of a solid
material with no moving parts.
 Have 3 layers so that a small voltage through
the middle layer controls a current between the
outer layers.
 Can act like switches

11. Series vs Parallel Circuits
 Microcircuits/integrated circuits:
 made up of microscopic transistors
and resistors