series resistors

[Xristakis795]

hi to all
if i have a resistor 39ohm 3watt
and i replace it with 4 resistors 10 ohm 3 watt
the total resistance and watt is the same with the first ?
or the watt is bigger ?

[petehall347]

Re: series resistors

resistance is additive .watts stay same

[Xristakis795]

Re: series resistors

very nice
something more sir i wanted to ask
if i use instead a resistor 2 watt 39 ohm which is burnt from a cockroach 39 ohm resistor 3 watt in a pcb circuit for kitchen is dangerous in your opinion ?
i ask more because i cannot find the electrronic manual and i am not sure if the resistance is 2 or 3 watt

[eccerr0r]

Re: series resistors

When you have multiple resistors it's not perfect but the wattage will spread and thus larger than single resistors.

Four series 10Ω 1W resistors will be 40Ω but the set will be able to dissipate 4W. It so happens to be easy to calculate in this situation because they are identical and identically connected.

You can always go up in wattage unless there's not enough space to fit or if the resistors were meant to go open before something goes up in flames.