Subject:
|
Re: IR collision avoidance
|
Newsgroups:
|
lugnet.robotics.handyboard
|
Date:
|
Tue, 18 Mar 1997 17:13:35 GMT
|
Original-From:
|
Chuck McManis <cmcmanis@#avoidspam#netcom.com>
|
Reply-To:
|
CMCMANIS@nospamNETCOM.COM
|
Viewed:
|
1554 times
|
| |
|
|
Sriram Tirunellayi wrote:
> could u please tell me where u bought the infrared LED's? The one
> that i bought from radio shack (part no.276 143) is giving a
> maximum range of 7.5 inches and i badly need to sense at least
> 1 foot.
The Radio Shack LEDs should work fine. The trick is that these things
are very sensitive to intensity, duty cycle, and frequency stability.
To modify intensity change the amount of current flowing through
the LED (lower resistor value == more current)
To modify duty cycle you will need to evaluate your signal source.
If you are using a 555 timer make sure that it is configured to
generate a near 50% duty cycle waveform.
To modify frequency stability either go to a crystal controlled
source or use tighter tolerance components (1% resistors, 5% caps)
Using the Radio Shack LEDs, 75mA, and a crystal controlled PIC to
generate the 40Khz signal, I could get range detection > 10 feet.
(not too useful indoors, except in a gym :-))
--
cmcmanis@netcom.com http://www.professionals.com/~cmcmanis
All opinions in the non-included text above are the sole opinions of
the author.
|
|
Message is in Reply To:
 | | Re: IR collision avoidance
|
| (...) could u please tell me where u bought the infrared LED's? The one that i bought from radio shack (part no.276 143) is giving a maximum range of 7.5 inches and i badly need to sense atleast 1 foot. thanks Sriram We didn't want that (...) (28 years ago, 18-Mar-97, to lugnet.robotics.handyboard)
|
2 Messages in This Thread:
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
