HO Scale Track Vacuum Update - Correct Logic

Added: 2026-05-11

[00:00:01]Hey everybody, Tech Billy 83 here and I wanted to give you a quick update on the uh track vacuum. So, this is the little side project I got going on. I'm working on an HO scale uh vacuum to run around the layout and clean up some uh of the mess.

[00:00:20]And I got finally uh some good progress and a little update for you.

[00:00:26]So, this is uh the old MOSFET that we were using, an IRLZ44N, and it worked as you saw in some last videos, but there was a logic issue.

[00:00:40]So, now I'm using a Come on, focus.

[00:00:51]Whoa.

[00:00:53]There it is. It's an IRF 4905.

[00:00:57]This is like a I think what they call a P gate logic or a P gate MOSFET. And that other one there is an N gate. Um so they behave a little differently. You uh wire up the positive um to your source and uh don't quote me on that. Hang on. See, this is the part where I'm not an electrical engineer.

[00:01:22]Yeah. So you wire the positive to the source.

[00:01:25]The drain actually goes to the positive on the fan and then uh the uh gate stays the same on uh the uh the MOSFET. So, I got the uh 10k resistor in there so that we uh don't have like uh false activations or noise in the the gate.

[00:01:53]And you can see here I've got a flyback diode between the positive and negative on the the fan to prevent back feeding into the system and you know causing havoc with the decoder.

[00:02:06]All right, so let's uh get a demonstration going here. So, we got our uh decoder selected here in JMRI.

[00:02:16]And let's uh burp the motor.

[00:02:23]All right. And you'll notice that by default, the fan is off. And that's kind of the behavior that uh we wanted here.

[00:02:30]So, we're going to grab our function function six here.

[00:02:59]All right. So, now we're in a spot where we got the circuitry figured out.

[00:03:06]and it functions the way it's supposed to. We're powering a 12volt fan off of uh a rectifier coming off a track voltage cuz uh as you see there, that wire is actually soldered right down to the rails over there. And I got, you know, some barrel connectors here to, you know, take it apart easily. Plus, I have like a little 6-in piece of track that I sometimes, you know, throw in here if I need to have something up closer or at a different angle where that uh SD45 is back there. That's uh you know, where stuff normally goes. But, all right. So, um now we've got uh this decoder controlling uh motors, not just the uh on the motor output. So, I can start thinking about uh you know what the actual uh car body is going to look like to house the fan and and what kind of car we're going to use so on and so forth. Um so I have to start sketching that up a little bit. I'll probably just do that on uh you know with a paper and pencil because you know that's the fastest way for me you know instead of learning some new software.

[00:04:24]Um, the next thing I need to figure out is uh like a small motor that I can attach a brass bristle brush to and then uh kind of build a support structure for that so that I can have like a little uh brass uh cleaning scrubber thing for the rails.

[00:04:46]Um because normally I would go through with the Dremel and put a you know the brassh brush on it and uh you know gently run that over the top of the rail and uh you know clean the heavy duty oxide and crud off. Um, I kind of want to incorporate that into this uh machine that I'm building here so that uh you know we can in one pass collect up any metal debris and suck up any dust and any other stuff and then uh you know give the the rail heads a good scrubbing and uh clean everything up nicy nice.

[00:05:25]So, if you happen to know of any like teenytiny 12vt motors or anything around 12vt that uh can interface with like a uh Dremel um brush, you know, like a 1/8 inch shank.

[00:05:45]I think Dremel is eighth inch shank.

[00:05:48]Or if there's just any motors out there that have like a little bristle brush built into them and like you know a whole self-contained unit. If you know of anything like that, throw it in the comments below so that I can check it out and then uh keep making progress here. So, hope you enjoyed this uh little video here. Kind of shorter than normal, but uh you can kind of see what's possible with uh enough tinkering. And uh stay tuned for more. Like, share, and subscribe and all that good stuff. Have a good one.