Inexpensive infrared train detector two circuits

Robert Frey

Member since
August 2006
From: Greendale, WI
108 posts

Posted by Robert Frey on Friday, April 3, 2015 9:10 PM

Bob Frey’s IR Cover Box Circuit

In this IR Cover Box project the 3MM IR DARK (940NM) photo Transistor is covered with a 0.15” black wide shield to form a 0.120” dia. viewing area. In the past a shrink tube with a 0.062” dia. viewing area was used. By putting two IR (940NM) in series, this increases the amount of light that can be detected to 3 feet. This IR Cover Box can be printed on card stock, or a 3 x 5 picture with 1”= 1” when printed. Link: http://1drv.ms/1CuZ9a4

Part No. Description: http://www.digikey.com/

754-1600-ND EMITTER IR 3MM 940NM CLEAR (50 ma) $1.87/10 (Em)
160-1030-ND PHOTOTRAN NPN 3MM IR DARK 940NM $2.70/10 (PT)
KSP13BU-ND TRANS NPN DARL 30V 0.5A To-92 $2.74/10 (T1)
PN2222AFS-ND TRANS NPN 40V 1A TO-92 CASE $1.99/10 (T2)
10KQBK-ND RES 10K OHM 1/4W 5% AXIAL $0.61/10 (R1)
100KQBK-ND RES 100K OHM 1/4W 5% AXIL $0.61/10 (R2)
680QBK-ND RES 680 OHM 1/4W 5% AXIL $1.22/10 (R3)
3.3KQBK-ND RES 3.3K OHM 1/4W 5% AXIAL $0.61/10 (R4)
220H-ND RES 220 OHM 1/2W 5% AXIAL $0.85/10 R5)
P14482-ND CAP ALUM 10UF 16V 20% RADIAL $2.20/10 (C1)
1080-1122-ND LED SS HI EFF RED DIFFUSED 3MM $2.84/10 LED
1N148DICT-ND DIODE SWITCHING 75V 0.15A DO35 $1.06/10 (D1)
277-1667-ND TERM BLOCK PCB 2POS 5.0MM GREEN $3.52/1 (TB)
3405K-ND BREADBOARD 1/16"DIA 2.00X4.50" $5.65/1 (BB)

Two IR EMITERS in series produce a stronger IR beam with the same dc current

Two IR EMITERS in series Cover Box

https://www.walthers.com/

904-299 Walters GOO -- 1oz 29.lmL, all-purpose adhesive. (Holds the folded cardstock and roof of the Cover Box.)

Search: 189-5934 US-Style Crossing Signal Set includes two crossing signals and flashing control unit.

The two EMITTERS IR cover Box and the Photo Transistor cover Box can be up to 3 feet away. The IR light is weak at 3 feet, but the LED still turns on when the beam is broken. The beam can be found by moving a pencil up and down. With the 0.062 brass tube in a drilled hole, both ends can be rotated, and moved up and down to find the flat cars, so that either car can stop our IR beam of light.

If the Train room has a large amount of IR light, then this simple circuit will not work when the weak IR beam is interrupted. Sensitivity to an ambient IR light problem can be adjusted by moving closer (stronger IR is interrupted) and changing (R2) to: 100K@3’, 68K@2’, 33K@1.5’, 10k@1’ or 4.7K@0.5’

http://home.cogeco.ca/~rpaisley4/IrProximity.html

Proximity Detector using the Vishay Electronics - TSOP4830 Infrared. This IR receiver is used as a sensitive detector that does not require shielding from room lighting. The IR detector will work under almost any lighting condition from complete darkness to full sunlight.

Note: The upper portion of the circuit uses two astable 556 oscillators. The lower portion of the circuit is the IR detector, time delay and output section. ROB PAISLEY shows the basic Infrared - Proximity Detector Circuit and Parts.