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Simple DIY Pulse/Feedback controllers for slow running, shunting and micro layouts, video in P2.


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[edit] 14-04-2021

 

I have altered the title of this thread a few times and this reflects the interest I see in this DC forum for a slow running controller. I send out to those who are interested a PDF with details of how to make the two in the video. I authored this to assume that the reader knows nothing at all about electronics.

 

Please send me a nice message with your email address and I will send it to you. I ignore one line phone speak demands.

 

 

Hello all,

 

Apologies for resurrecting an old thread I do have some information to impart. This is aimed purely at those who like shunting layouts of the micro variety. 

 

A few years ago I came across Jonathan Scotts pages with a circuit diagram of the GM UF controller (now £55 special order only) Very simple only three semiconductors and very very effective.
Here's one on some stripboard.
B_GM_UF_Vero.jpg.b4fdef762336577a6d2a6f4ef9f9b45e.jpg

 

I started the 2013 thread with the Brian Tilbury pulse/feedback controller again using just three semiconductors. It is now on the MERG site posted by Stewart Hine some years ago who sadly died recently.
Here's one I made a few days ago, ready to be fitted into one of my micros.
BT_CircuitVeroBoard.jpg.2c4d5d8280f24da178132471ef2ae148.jpg

 

It's more complex than the UF. I will be doing a comparative video and will post that as soon as I have done it.

 

Cheers - Jim

 

Updated from this post in 2013 

Edited by JimRead
even more additional info
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Posted (edited)

Hello all,

Here's the video of the comparison;

 

[edit] Best at full screen and 1080p

 

[edit2] Please watch with the sound and then without it they do start just as slowly, it's the noise of the UF one that fools the eye.

 

I have also combined the two circuits, instructions, semiconductor pinouts, resistor colour chart and hints and tips etc into one PDF.

 

I will gladly send this to anyone who sends me a nice message through the site with their email address. I ignore one line phone speak demands.

 

Cheers - Jim

 

PS If anyone had built something akin to these using only three semiconductors and giving pulses and feedback, I would love to hear about it. There have been many controllers with far more complex circuitry that do not work as well as these and I like an eejit have made a number of them.

Edited by JimRead
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  • JimRead changed the title to Update from 2013, a pulse/feedback controller for micro layouts - Video comparison in P2
  • 2 weeks later...

Hi Jim,

 

I've built both these controllers, as well as 8 other different ones. I'm still deciding which are my favourites!

 

I think that your UF is still firing the SCR at zero speed and I would suggest you reduce the value of the 22k. In the one I made I put another 22k in parallel with the existing 22k to give 11k. The original apparently had a 10k trimpot.

I have N gauge models, mainly from the 1990s.

 

Also, you mentioned the motors you use start and run at low current. That's ok, but these 2 controllers were designed for the motors of their time and may need tweaking to give best performance with low current motors, such as you are using.

 

Thank you for the comparison video. I only recently joined RMweb, but have been a lurker for a while and have read your older controller posts.

 

Thanks,

Mark

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Hello Mark,

 

Many thanks for the comments and the anecdotes a few years ago I found this page: https://www.scottpages.net/ReviewOfControllers.html and used the original UF circuit therein, the D13T1 UJT is not available in the UK so I used 2N6027 instead, with the 10k resistor the circuit would not switch off, once doubled it did. I've also made the other two circuits that are now on that page the Mk2 hums down to zero and the Mk3 works the same as the first one.

 

The Mk1 and Mk3 used in the video, do switch off but just after the loco has stopped, the Brian Tilbury one switches off completely when the loco stops, it's quite sophisticated and was originally designed for the 2mm association and consequently for motors that require miniscule amounts of power (low current) to move. By changing a few components it can be used for OO and O gauge up to 3 Amps. In the video I use the 2mm version.

 

May I ask if any of the other 8 that you have made have pulses and feedback and if so would it be possible to see the circuits. If they are as easy to make as the two in my video and are quieter I will gladly do another video.

 

Cheers - Jim

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Hi Jim,

 

Brian had 2 circuits, so I made the NPN version of the 2mm Scale Association controller that Brian published in the 2mm Scale Association magazine. I've sent you a PM with the other 8 controller articles/circuits.

 

For sheer simplicity and excellent operation the Roger Amos Project 7 "Sensitive Closed Loop controller" takes some beating. Although it has 3 transistors in the original circuit, I used a BD682 darlington, to make a 2 transistor controller.

 

Mark

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  • JimRead changed the title to Update from 2013, a pulse/feedback controller for shunting & micro layouts - Video in P2

Hello Mark,

 

Thanks for sending me all that stuff very interesting to read it all. It's surprising how complex electronic engineers like to make things. I was sitting on the lav at Wolverhampton Borough Council and on the wall was written this;
"I went to colej to ger ejukated
Now I are a engineer"

 

I have tried Mr Amos's No 7 circuit from his No2 book sadly the result was nowhere near the claims the gentleman makes for his circuit. It is quiet though, but the "feedback" is non existent as are the "slow starts" it would be fine for speedy roundy roundy layouts but useless for shunting.

 

If anyone would like to see a comparative video I will gladly do one, I do model in O Gauge and for the comparison I would use a motor that starts at 0.04 Amps.

 

Cheers - Jim

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On 29/03/2021 at 23:51, JimRead said:

Hello all,

Here's the video of the comparison;

 

What superb running!

 

I wouldn't know where to start, in terms of actually building any of these controllers (for 4mm scale use, DC), but I would pay good money for someone else to build one for me!

 

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Hello CK,

 

Thanks for the nice comment good of you, it's surprising how such simple circuits can produce such fine results. I do a PDF that shows how to make either of these and assumes that the person reading it has no electronic knowledge at all. I taught myself in the 80's to recognise components and convert a diagram to something that works, that's all that is needed.

 

Drilling boxes is a pain this is mounted on 2mm grey card
BulitIn1.jpg.4d79ad10e2d8aa45e0d7b72541266341.jpg

And sits in a hole in a baseboard.

 

The stripboard is simply hung from the card
BulitIn2.jpg.6ea29c2a9d84c73614ac368db249e431.jpg

 

I will gladly send you the PDF if you would like to have it, please let me know your email address. You will be able to make as many as you like for peanuts after the 1st one.

 

Cheers - Jim

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  • JimRead changed the title to Simple DIY Pulse/Feedback controllers for slow running, shunting and micro layouts, video in P2.

Hello Jim.

 

Thank you for your rude post. I'm glad that we can all spell engineer.

My aim is to share my experience with DIY DC controllers. I thought this was your aim as well.

As I said in my PM to you, I model N gauge, so I could expect different outcomes from the different controllers from what you experienced.

Please, stay safe, stay well.

 

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Hello Mark,

 

Please accept my sincere apologies, it's my fault entirely.

 

I started the thread with the main word 'micro' in the title thinking erroneously that people reading the thread would think it related to something specific rather than a general controller thread.

 

I realised this yesterday and have changed the thread title to reflect it. I should have replied to you to explain this before proceeding with the title change, do forgive me.

 

If you should come across any simple circuits that anyone can make please feel free to post them here. Other threads in this forum indicate that there is a need for this with the ever increasing amount of micro layouts being constructed.

 

I do hope the above explanation ameliorates the situation and again please accept my apologies.

 

Cheers - Jim

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Hi Jim,

 

All good. I was being a bit tongue in cheek.

I'm sure we are all here to share and learn, and I think this is a really interesting topic and you have it well supported with the video. Like I said earlier, I've been a long time follower of your posts.

 

Cheers,

Mark

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