Just thought I'd throw this one out there, as I'm sure there must be a simple explanation... When I've been looking at many DIY timers, it seems that the transmitting LED is placed on top, the receiver on the bottom. Isn't that a recipe for interference from the ambient light?
Or is the flash of reflected light from cars finishing a worse situation to have to deal with if the receiver were to be placed on top?
infra red timers - why is the receiver on the bottom?
- gpraceman
- Site Admin
- Posts: 4926
- Joined: Fri Jun 20, 2003 12:46 am
- Location: Highlands Ranch, CO
- Contact:
Re: infra red timers - why is the receiver on the bottom?
It is less likely that the light will bounce off the track, then bounce off the underside of the car and then blind the sensor to the passing of the car over it.
Randy Lisano
Romans 5:8
Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.
Romans 5:8
Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.
Re: infra red timers - why is the receiver on the bottom?
aaah, that makes sense... so, it would be one step better to paint that section of the track black also?
- gpraceman
- Site Admin
- Posts: 4926
- Joined: Fri Jun 20, 2003 12:46 am
- Location: Highlands Ranch, CO
- Contact:
Re: infra red timers - why is the receiver on the bottom?
Absolutelymadumi wrote:aaah, that makes sense... so, it would be one step better to paint that section of the track black also?
Sent from my SM-T550 using Tapatalk
Randy Lisano
Romans 5:8
Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.
Romans 5:8
Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.
Re: infra red timers - why is the receiver on the bottom?
The Judge timer from newdirections does have the light source in the track and the sensors on the bridge. In my experience it has the least issue with light reflectivity.
Maybe better than flat black paint is to reduce the size of the aperture in the track. An 1/8 inch hole is big enough so sense the light, but too small to allow reflectivity.
For more information:
http://www.maximum-velocity.com/pinewoo ... imes-v7i2/
Maybe better than flat black paint is to reduce the size of the aperture in the track. An 1/8 inch hole is big enough so sense the light, but too small to allow reflectivity.
For more information:
http://www.maximum-velocity.com/pinewoo ... imes-v7i2/