I am a dummy. I'm not very good when it comes to wiring LED's and etc. I would like to get into modifying and toying around with random stuff. I just don't know how to decide what power source for what task and what kind of resistors to use for what kind of power. Could you guys help me out and come up with a little quick reference guide. I would greatly appreciate it.
Ohm's law. It's very simple. If you google for LED circuit calculators, you'll find about a billion sites that'll do all the math for you. As for power source, go through your unused power adapters, find appropriate voltages (3V, 5V and 12V are good places to start,) strip the cords, and you'll never have to mess around with batteries unless you're building something mobile.
1. Datasheets of the LEDs u r using (maximum cont. forward current value)
2. Ohms law (Voltage applied [V]/ < max. con. fwrd A) = resistor [Ohm] - determining the resistor and thereby how much current through the LED
3. breadboard
njoy <3
2. Ohms law (Voltage applied [V]/ < max. con. fwrd A) = resistor [Ohm] - determining the resistor and thereby how much current through the LED
3. breadboard
njoy <3
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...show me the schematic
...show me the schematic
This is the way I was taught
Whatever you wish to measure, cover with your hand.
Then the calculation is presented to you.
eg cover V and you get I|R which is therefore (I * R)
cover R and you get
V
-
R
which is V/R
Whatever you wish to measure, cover with your hand.
Then the calculation is presented to you.
eg cover V and you get I|R which is therefore (I * R)
cover R and you get
V
-
R
which is V/R
V = VoltageAussieReaper wrote:
This is the way I was taught
Whatever you wish to measure, cover with your hand.
Then the calculation is presented to you.
eg cover V and you get I|R which is therefore (I * R)
cover R and you get
V
-
R
which is V/R
R = Resistor
I = ?
What is the highlighted part?Beduin wrote:
1. Datasheets of the LEDs u r using (maximum cont. forward current value)
2. Ohms law (Voltage applied [V]/ < max. con. fwrd A) = resistor [Ohm] - determining the resistor and thereby how much current through the LED
3. breadboard
njoy <3
Last edited by NeXuS (2011-12-30 13:35:08)
Choose a current value lower than the maximum continuous forward current/ DC current specified in the datasheets.NeXuS wrote:
/ < max. con. fwrd A)
What is the highlighted part?
but now that i think of it.. u also need to look at the maximum power dissipation.
Ohms power law: Power [W] = I [A] x U [V]
example from datasheets
in this datasheet the continuous forward current is called DC current, but as you can see the maximum current for this multi-color LED is 30 mA. so i would say 20 mA-25 mA depending on how bright you want it to be vs. life time of the LED.. BUT, u also need to know how much voltage will be applied across it, so you would stay under the maximum power dissipation.
Lets say you have 2 x 1.5 V batteries and the LED mentioned above:
just instert in Ohms power law:
(75 mW) / (3 V)= 25 mA
..now you now that the red led which has the lowest maximum power dissipation, will not blow.. the green is all safe, cause it has higher max. pwr diss.
Next step will be to calculate the resistance needed to limit the current of 25 mA at 3 V:
Ohms law: (3 V) / (25 mA)= 120 Ω
A resistor of 120 Ω in series with the LED will make sure that no more than 25 mA will run across the resistor...at 3 V!
<3
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...show me the schematic
...show me the schematic
NeXuS wrote:
I am a dummy. I'm not very good when it comes to wiring LED's and etc. I would like to get into modifying and toying around with random stuff. I just don't know how to decide what power source for what task and what kind of resistors to use for what kind of power. Could you guys help me out and come up with a little quick reference guide. I would greatly appreciate it.
Current (Amps) = Potential (Volts) over Resistance (Ohms)
All you really need to know for very basic circuitry.
"Ah, you miserable creatures! You who think that you are so great! You who judge humanity to be so small! You who wish to reform everything! Why don't you reform yourselves? That task would be sufficient enough."
-Frederick Bastiat
-Frederick Bastiat
Okay well I'm using a website that calculates everything for me and it's helping out a ton. I got a question about the power source. Here's the diagram.
Where it shows the voltage coming from the 5v source it's only one line. My 5v adapter has a positive negative and ground. How do I wire that if the diagram only shows 1 line?
Also which LED's are the brightest? I know of 3mm 5mm 8mm Surface mounted and high powerted ones that are 1 watt.
Using this website
http://www.superbrightleds.com/cat/comp … /overview/
Where it shows the voltage coming from the 5v source it's only one line. My 5v adapter has a positive negative and ground. How do I wire that if the diagram only shows 1 line?
Also which LED's are the brightest? I know of 3mm 5mm 8mm Surface mounted and high powerted ones that are 1 watt.
Using this website
http://www.superbrightleds.com/cat/comp … /overview/
Last edited by NeXuS (2011-12-30 18:11:55)
Negative goes on at the connection point opposite the positive in the schematic.NeXuS wrote:
Okay well I'm using a website that calculates everything for me and it's helping out a ton. I got a question about the power source. Here's the diagram.
Where it shows the voltage coming from the 5v source it's only one line. My 5v adapter has a positive negative and ground. How do I wire that if the diagram only shows 1 line?
Also which LED's are the brightest? I know of 3mm 5mm 8mm Surface mounted and high powerted ones that are 1 watt.
Using this website
http://www.superbrightleds.com/cat/comp … /overview/
Pop over to radioshack and pick up a hobby kit. It should provide enough basic information and activities for you to see if you really like component-level electronics. If you do, then you can start doing things like learning boolean algebra for truth tables, learning how to diagram components and circuits, memorizing resistor color codes and basic electronics formulas.NeXuS wrote:
I am a dummy. I'm not very good when it comes to wiring LED's and etc. I would like to get into modifying and toying around with random stuff. I just don't know how to decide what power source for what task and what kind of resistors to use for what kind of power. Could you guys help me out and come up with a little quick reference guide. I would greatly appreciate it.
In time, if you feel you're pretty comfortable with that, grab yourself a Z80 processor, a larger breadboard (if yours isn't) and a better power supply and see if you can make yourself an elevator.
If you prefer not to learn on your own and don't mind paying a bit more, courses at tech colleges are generally sufficient.
e: If you're prone to burning stuff, get some adequate ventilation.
The pie chart in this link is clever, and includes 'power.'
http://www.electronics-tutorials.ws/dcc … dcp_2.html
i love that site^ used/use it a lot
الشعب يريد اسقاط النظام
...show me the schematic
...show me the schematic