What exactly does the resister do in electronics and such.

[Buckshot]

For example:

+-------->-----RESISTER----|-------|
LED LED
| |
-_____________________________

Leds wired parallel. I believe this diagram is right. What is the need of
the resister if:

Source Volts: 5
Draw per LED: 3.7V

What exactly is it doing. Sorry if Im sounding/looking amature I want to
learn though.

Buck

 

[Brian Gregory [UK]]

For example:

+-------->-----RESISTER----|-------|
LED LED
| |
-_____________________________

Leds wired parallel. I believe this diagram is right. What is the
need of the resister if:

Source Volts: 5
Draw per LED: 3.7V

What exactly is it doing. Sorry if Im sounding/looking amature I want
to learn though.

Buck

RESISTOR
AMATEUR

Without the resistor the LEDs would have 5V across them and they would
burn out in a fraction of a second.

 

[Reason]

RESISTOR
AMATEUR

Without the resistor the LEDs would have 5V across them and they would
burn out in a fraction of a second.

Voltage is not load. Voltage is "electrical pressure." (in water, p.s.i.)
Amperage is "electrical flow." (in water, gal. per min.)
Resistance is the amount the "flow" is restricted by load.

 

[Art]

Physically the resistor is placed between the current source, be it a
battery, etc and the load, in your case the leds. The purpose is to limit
the current flow through the whole circuit, but more specifically the
applied current to the load, your leds. In doing this heat is dissipated at
the resistor and a voltage drop is developed across the resistor. Therefore
the applied voltage and currents applied to the load, your leds, will not
exceed the manufacturer specifications. As stated, without limiting the
current and voltage to the leds they will surely fail in a short period of
operation. Formulae I=E/R Current equals voltage divided by resistance, for
a purely resistive load.
Hope this helps kiddo, keep on asking questions, inquisitive minds are never
bored!! Cheers

 

[JeffM]

+-------->-----RESISTER----|-------|ASCII art is done in a monospaced font (Courier).
Set your newsreader accordingly or use Notepad.

Leds...What is the need of the resister if:
Source Volts: 5
Draw per LED: 3.7V
Buckshot

Items do not "draw" voltage; they draw current.
Subjects to investigate:
1) Ohm's Law 2) Voltage drop
This is covered on Day 1 of Electricity 101.

:RESISTOR
:AMATEUR
: Brian Gregory
:
LEDs


Note: LEDs in parallel may not be the same brightness
(manufacturing tolerances/lots).
If 1 LED fails shorted (typical for a semiconductor), both will go dark.
Translation: If looking for redundancy, not the optimal circuit.

 

[Buckshot]

Thank you guys, I understand now, and Brian you don't have to be a dick
jesus. Thats why I was asking, I'm NEW.

Buck

 

[FPF Info]

It limits the current through the LEDs. The value of the resistor should be
calculated so that in the case you specify (though it looks different to the
diagram, I must say) the (5-3.7)V across it should only allow about 20mA
through it, otherwise the leds will burn out pronto

 

[FPF Info]

If the LEDS are parallel, then the Voltage drop should be 1.7V, NOT 3.7V!