0030 Point motor control from Raspberry Pi Pico

[@iansngauge]

Hi Jonathan! Looks like you're making some good progress on the electronic side of things - even in short bursts! I had a brief flirtation with an Arduino a few months ago, and have collected some bits and pieces of electronics, including some of those 'optical' relays! I'm sure I read somewhere that each side of the relay should have different power sources to ensure the optical sensor couldn't be bypassed! I can't find the article now, but if I come across it, I'll forward it on! All the best, Ian.

[@endoorrailway]

Hi Ian, progress of some sort, at least :) It's always been in bursts, but this time around it caused a bit of a continuity issue when compiled into a video so I thought I'd best mention it! That's interesting - what you think you found matches how I think it should be, but with the modules I've got I can't see any way of actually doing that (I tried not having a connection to ground, but nothing happened). If you do happen to find that link when you next come to this stuff that'd be great, thanks!

[@iansngauge]

@@endoorrailway - I've had a quick look through the articles I bookmarked while I was doing research, but I can't find the one that mentions it at the moment! I'm bound to come across it again at some point, and will let you know! Ian

[@endoorrailway]

@@iansngauge Hi Ian, it's kind of you to have taken the time to do that, thanks!

[@tonyshield5368]

Its coming along nicely. Like you pointing out the potential 'Gotchas'

[@endoorrailway]

Thanks, it's gradual but feels like it's getting there! I go through quite a lot of thinking I've got something sussed and then finding gotchas, so I put them in there in case they're helpful :)

[@VP_H0]

Hello! Thanks for the review. Does it happen that the relay's physical contacts open the impulse? Won't they burn out over time? The current for the solenoid is quite large. In my case, the Gaugemaster solenoid has a resistance of 2 ohms on the H0 scale, and requires 20 volts for normal operation.

[@endoorrailway]

Hello 🙂 I can't say for certain how they work inside, but from the various videos I've seen about relays I suspect an electromagnet and spring pull a lever between one contact or the other, and the current for the load (the power for the solenoid), will go through those contacts. The relays say they're OK for 30V DC, and I think the reason relays exist is to use a low-voltage circuit to switch a high-voltage circuit, but I think eventually their contacts do burn out. I haven't got enough first-hand experience to know how long that will be, I'm just hoping it's a long time!

[@VP_H0]

Yes, I see. Thanks for the answer. I was wondering how to solve the automation problem with these solenoids. They require a capacitor discharger. My buttons were welded from a spark :) I found a solution using a transistor key. A small current from the decoder opens the transistor for a large current and then nothing burns. You can solder the circuit yourself. I will make a review on my channel in some time.

[@endoorrailway]

Oh, yes I do have a capacitor discharge unit on the layout - that's what the relays connect the solenoid to (I've got a later video where I finished integrating the Pico to the points control). I must admit I don't really know how to use transistors properly - when I've tried to learn it seems like the control current can't be wildly different to the big current, or there'll be lots of heat, but it does sound better if it can work - no moving parts is often a better way to go :) Thanks

[@stratosphere2133]

Your 'scraps of time' must be very busy and cause no few headaches!

[@endoorrailway]

They're not so much busy as just very fractured, which definitely makes it harder to think things through! But work and family life etc. come before hobby :)