My dad has a small DC Christmas layout that he is in the process of adding a trolley to. He would like to automate it so it will run back and forth on its own. I know there are commercial units available, but I came across this webpage (<== double click to see)with a couple of circuits that seem like they would work. I am looking specifically at the "1st inexpensive reversing circuit" and the "4th inexpsensive..." The circuit seems easy enough to put together, but I am no eletrical engineer, and a novice finger burner at best...I am trying to figure out what parts to order from Mouser - specifically the rheostats marked R1 and R2 on the "1st inexpensive" circuit and on the "4th inexpensive..." the photocells (Q1 & Q2), the relay (is this a SPST 12V?) and capacitor marked .1uf (no voltage indicated?). I'm sure there is someone way smarter than me that will know the answer!
Has anyone put together one of these cicuits before? Any advice or hints?
As always thanks for your expert advice and opinions.
Circuit #1 -- R1 and R2 One selection would be ALPHA 24mm Potentimeters. They come in several mounting options depending on how you plan to mount the parts. They come in chassis mounts and PCB mounts. Cost is under $2. The 555 timer is a DIP chip and would require some kind of circuit board mount.
The electrolytic capacitors can be of higher voltage than listed and may be easier to find. The .1 uf can be any voltage highter than 15 volts and usually are rated at least 100 volts.
Radio Shack may have the parts but most stores are limited.
Generally these are proven circuits. It may be difficult without much knowledge of electronic components. Mouse has a very good selection but the catalog is huge and can be difficult online. I have their paper catalog and it is huge.
Take time and look carefully.
I am going to PM you with a list of online vendors I have bought from. I keep a list for this purpose. Might add confusion, hopefully not.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Reformed GrownupI am trying to figure out what parts to order from Mouser - specifically the rheostats marked R1 and R2 on the "1st inexpensive" circuit
R1 & R2 are 1meg Ohm variable resistors or potentiometers, styles vary as mentioned.
Reformed Grownupon the "4th inexpensive..." the photocells (Q1 & Q2)
These are phototransistors or photocells.
The 555 Timer IC will require an 8 pin DIP socket on the protoboard as mentioned
I did some reverse looking at this guys site and found ths information for the photo transistors.
Mouser should have them also. Different part number but the real transistor number may be in Mouser. Have not used thse in sometime but I do not believe there is much difference in different brands of photo transistors.
Digi-Key part number is 160-1030-ND
Digi-Key site.
http://www.digikey.com/
I have ordered from Digi-Key many times. They have over 3000 in stock.
http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=160-1030-nd
richg1998 Generally these are proven circuits. It may be difficult without much knowledge of electronic components. Mouse has a very good selection but the catalog is huge and can be difficult online. I have their paper catalog and it is huge. Take time and look carefully. I am going to PM you with a list of online vendors I have bought from. I keep a list for this purpose. Might add confusion, hopefully not. Rich
Thanks for the PM. You are right about the Mouser "booster seat". there are a lot of options...too many options when you don't really know what you're looking for to begin with
I just rec'd my first order from them, they ship fast and the charge was reasonable - a whole lot better and cheaper than the local "Shack" - the exact opposite end of the "option" scale... my local store doesn't even carry these do-higgies! OUTRAGE!
I design my own. This topic come up at least once each year around this time.
http://cs.trains.com/trccs/forums/p/49226/624426.aspx#624426
Note that mine above does not have a timer nor stop at either end, so it is only for slow speed operation where it is not going to hurt the locomotive to be instantly thrown into reverse.
I got all of the parts for this at Radio Shack. I can't believe yours doesn't at least have one cabinet of do-hickkies.