Subject:
|
Re: Homemade LED Bricks
|
Newsgroups:
|
lugnet.robotics
|
Date:
|
Fri, 12 Nov 1999 03:04:44 GMT
|
Viewed:
|
715 times
|
| |
|
|
Michael Gasperi wrote:
> David Johnston <lego-robotics@crynwr.com> wrote in message
> news:LOBBJCENKNHFLCKICLNNIEODCAAA.djohnston@tinet.ie...
> > not being an electronic engineer, what is "appropriate"?
>
> I'd say 330 Ohm 1/4 Watt.
Er, 330 ohm may be ok for the usual transistor type circuit where the
nominal supply voltage is 5 volt, if my memory has not failed me.
It may be a bit low, I think, for the RCX where the nominal voltage is 9
volts which is almost double of 5 volt. So maybe a resistance of 680
ohm would be more "appropriate"?
But then I'm not an electronic engineer either. Just wanted to be sure.
--
C S Soh
http://web.singnet.com.sg/~cssoh
... where air is power
|
|
Message has 1 Reply:
 | | Re: Homemade LED Bricks
|
| basicly.. it's i*r=v where i = current in amps and r = resistance in ohms and v = voltage in volts.. so.. If we want to find out the resistor's value.. we re arrange it like so.. r = v/i so 10 millamps (typical led current) = .01 Amps.. And at 9 (...) (25 years ago, 12-Nov-99, to lugnet.robotics)
|
Message is in Reply To:
| | Re: Homemade LED Bricks
|
| David Johnston <lego-robotics@crynwr.com> wrote in message news:LOBBJCENKNHFLCK...inet.ie... (...) I'd say 330 Ohm 1/4 Watt. (25 years ago, 12-Nov-99, to lugnet.robotics)
|
23 Messages in This Thread:
  
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
