Jon,
What driver circuit are you using? That makes a huge difference, but regardless of the driver not all IR detector pairs are created equal. The specs on the TCRT5000 show 15mm (aprox. .5 inch) but that is tested with a mirrored surface. I have had good luck with a pairing of LiteOn LTR-4206E LED and LiteOn LTE-4206 phototransistor. These are discrete T-1 package, and require some sort of light shield between them on installation. Also, the LTE-4206 phototransistor has backward polarity, the positive is the short lead/ flat edge. I find I have no problem detecting up to an inch with black bottom cars (HO scale), but that is with my own amplified driver.
Barry Draper
________________________________________
From:
[email protected] <
[email protected]> on behalf of Jon Miller <atsfus@...>
Sent: Sunday, August 12, 2018 1:10 PM
To:
[email protected]Subject: [jmriusers] I/R detectors
This may be a little off topic for this group but I need some engineering help. I'm using some TCRT5000 Infrared detectors (eBay). When testing a light brown colored underframe the detector will trip at about 1". However when the underframe is black that reduces to about a 1/4". [there is more to this story but later if required]
My question, if I increase the current to the IR LED (by decreasing the resistor) can I get more range? It appears the resistor now is around 30mA but the device specs say it could take 60mA. Maybe take to 45mA!:-\
--
Jon Miller
For me time stopped in 1941
Digitrax Chief/Zephyr systems, JMRI User
SPROG User
NMRA Life member #2623
Member SFRH&MS
