electrical quesetion series/parallel

[vijay]

Could someone possibly expalin to me what is meant by series and parallel wiring and where you would use each type and the merits. Also do you suffer any voltage/power drop when connecting e.g multiple lights in a particualr way?
thanks for the enlightenment...

 

[breezer]

i am no good at drawing so try this.

christmas tree lights are in series.

The supply goes in the left side of the lamp and out the right side, then in the left of the next lamp and out the right, you with me so far?

In the case of christmas lights a wire is run from the last light back to the begining so that you have 2 wires to connect to, but there is no reason why you could not have lights on this wire too.

As christmas tree lights are 12v (usually) by having 20 in series that maans that you have 20 (lamps) @ 12 v = 240v

so these can be plugged directly into the mains (mains being 240 v)

(i only said in on the left and out on the right because i t was a 50 / 50 choice it does not actualy matter which way is in or out)


Paralel is different. (your sockets are in paralell)

Imagine the same lamps.
Now imagine two paralel lines, you connect each lamp across each line (as opposed to in and out (series)

The advanges are er um sorry i cant think of any just now, but the reasons different things are done is to do with the "thing " you are using, you wouldn't want 240v on christmas tree lights would you.

Edited by breezer to add

I found this drawing

 

[MANDATE]

Just to add a bit more information.
If you wanted two lights from the same power supply of say 240 volts and you wired them in series the voltage across each light would be 120 volts and the lights would be half the brightness, likewise if it was four lights then 60volts across and quarter the brightness,so you wouldn't do it that way

 

[garlicka]

Parellel - voltage across all items in a parellel circuit is the same as the driving voltage. e.g. in a house all wall sockets are connected in parallel thus they are all at the driving voltage (240V) the current is likely to be different through each arm in the circuit (dependant upon the resistances of the items uesd). The current dpends upon the V=IR equation.

Series - the current through all items will be the same. The voltage drop across each item can be determinded dividing the resistance of the item by the total resistance of the circuit and multiplying by the driving voltage. See previous relpy (xmas tree lights for an example)

Regards
Andy

 

[vijay]

Thanks very much for that guys.
enLightened!!