# Model Train Track detector Updated twin-t model train track detector circuit parts list?

Model Train Track detector
Does anyone know what the parts are for this updated twin-t model train track detector circuit?
See Fig. 5-5 in "Easy to build Electronics Projects for Model Railroaders"I checked twice with the publisher for the missing parts list in the article but never got a reply.
C1 - ?? , C2 -??, D1-D6 - ??, D7 - ??
Q1,Q2 - TIP 142
R1 - ??, R2 - ??,R3 - ??
Thanks, AB

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steveastrouk7 years ago

All the diodes 1N4007
C1,C2 o.22uF or bigger, but not electrolytics.
R1,R2 - try 1K
R3 guess at 2K2

Its hard to read the functions of the pins, so R3 may need some experimenting.

Steve
steveastrouk7 years ago
Put the circuit up, and I'll take a guess.
brownart (author)  steveastrouk7 years ago
Thanks everyone for your replies. I am sorry that I did not make my request clear. I have attached the circuit for which I am trying to find the values, the article did not contain the normal parts list for this circuit. I know that Q1 & Q2 are TIP 142 transistors or I can use the smaller-case TIP 120s. The unknown capacitor (C1 & C2) values, the unknown diodes (D1-D6) values and the unknow values of resistors(R1-R3) are what I was hoping someone could provide and had already built for their train layout. AB
lemonie7 years ago
(alternatively http://www.google.co.uk/#hl=en&q=twin-t+model+train+track+detector+circuit&aq=f&aqi=&aql=&oq=&gs_rfai=&fp=4da16c650c5b86c8)
D usually stands for Diode
C usually equates to Capacitor
And R=Resistor.

L
7 years ago
.  ... and Q is usually a transistor.
.  TIP 142 is a power transistor. Google is your friend.

.  You really need to post a link to a schematic (or, at the very least, a parts list) for ppl to be able to help much.
7 years ago
(Oh I missed out Q...)