A pulsed/feedback current limited controller - Instructions and video

[relaxinghobby]

 

 

 

Hi Jim

 

I've started work on the circuit, I've had a dry run and placed each component by tucking their tails into the holes in the strip board, then marking the positions with a marker pen.

 

I have made mistakes with circuits like these in the past, so that at the end I have a non-working gadget for my trouble. It is much easier using electronic kits where the printed circuit board and the component arrangement has been worked out for you, all you have to do is put each component in the marked positions and solder.

 

But with the strip board system it is much harder following the circuit diagram and converting it to real form because the actual components are often much smaller or bigger than their diagramatical representation.

 

I only have basic test equipment, a light bulb, a motor as this is a motor control circuit and a digital volt and amp meter, which was a bargain from Ldle.

 

So I will proceed step by step testing as I go.

 

Here are the power leads fixed, the 4 diodes that form the bridge rectifier and the first resister.

[Guest Jim Read]

Dear RH,

 

When you get the circuit to work you will be delighted not only that you've done it but that it works so well.

 

It is the next stage up from a kit at least you know what the components look like and kits are quite easy, this requires a bit of thought. But next time you see a circuit you will think ahhh yes I can make that :-)

 

Just a few little tips; when you fit a component that is parallel to the copper track below cut the track with a drill in your hand, ditto to separate one section from another where components share the same horizontal copper track, you can mount a resistor or diode upright to save space and some components can be used as connectors, R3 for example from the negative line to the emitter of the 2N3055.

 

I have made these as handhelds using a tiny board a DC supply and point to point soldering.

 

If you have any problems let me know here, it will help others.

 

Cheers - Jim

 

[edit] Imagine that the horizontal lines on the diagram are the horizontal tracks on the veroboard, start at the top right work inwards to the left and then down to the neg rail, use my pic above as a guide.

[gormo]

Hi Jim,

          I have just come across this topic and am finding it very informative. The video is quite impressive.

I wonder if you could forward the appropriate PDF`s to me as well with as much info as possible. I would like to have a go at building this controller.

          Thanks in advance

Gormo

[mdcronin]

Hello all,

 

Please read this thread all the way through there's not that much and there's a link to a video further down. The circuit and instructions are available, in exchange for a polite message with your email.

 

Please note;

Brian Tilbury has asked that the controller be shared amongst enthusiasts but not published anywhere, I would ask anyone who wants the circuit to respect his wish.

 

Read on ...............

 

I use a circuit designed by Brian Tilbury in 1974 for the 2mm Association and later uprated for more powerful motors. One of the 'good' things I am able to do with this is to build it into the baseboard of my layout

 

These are the bits laid out ready to be assembled, mostly from Cricklewood Electronics except for the posh knob and the DPDT on-off-on switch which I bought on eBay.

 

 

More as I build it.

 

Cheers - Jim

Dear Jim,

 

Please could you forward me the schematic.

 

Thank you, best regards,

 

Mark Cronin

[mdcronin]

Hi Jim,

 

Your smooth controller looks perfect for my shunting yard, please could you send me the PDF you refer to.

 

Thank you very much and keep up the good work.

 

Best regards,

 

Mark.

[Guest Jim Read]

Hello Mark,

 

Thanks for your interest and the message, the instructions are on the way to you.

 

Hello all,

 

To anyone who would like the instructions and diagram, please send a message with your email address through the site please. The file is 1/2 Meg and would soon clog up my RMW message box.

 

Cheers - Jim

[mdcronin]

Dear Jim,

 

Thank you very much, please let me complement you on the quality of the documentation, something to aspire to.  I'll keep you posted on progress, which will start this morning!

 

Thanks again and very best regards,

 

Mark.

[Trevor Mullins]

Jim, only joined recently, but very interested in the pulsed feedback controller after seeing your video! Would you please send me a copy of the circuit diagram and notes.

Thanks Trevor Mullins

[Guest Jim Read]

Hello Trevor,

 

Email on the way to you.

 

Cheers - Jim

[Chuntybunt]

Hi Jim, I would be grateful if you would send me a schematic for this controller. It looks as though it would be a good choice for the shunting sections of the layout I am planning and I also just like building and trying different controllers.

 

Regards

 

Mike

[Guest Jim Read]

Hello Mike,

 

I will be delighted to send it to you, please send me a PM with you email address.

 

Cheers - Jim

[ejstubbs]

I'm very interested in this controller.  Given that Jim's account seems to have been removed, is there anyone who received the schematic from Jim who could share it with me?

[cliff park]

I hope this works, it is a PDF with diagram and other relevant info. If it fails PM me and  will e-mail it.

[cliff park]

Sorry Andy. I presumed that as the design originated from 1974, and that Jim Read's account has now gone, it would not hurt to publish it. I have sent ejstubbs a pm with attached PDF, hope that is ok

[Donw]

Sorry Andy. I presumed that as the design originated from 1974, and that Jim Read's account has now gone, it would not hurt to publish it. I have sent ejstubbs a pm with attached PDF, hope that is ok

 

Cliff the design was not Jim's. Brian Tibury designed the circuit and it was his wish that no one should publish it or make any profit from it but was happy for it to be passed on to others. Brian is still around and still modelling. My copy of the circuit was for 2mm use, Brian may have uprated some components for 0 gauge use. The circuit was not designed for coreless motors, interestingly it was a friend of Brian's Stuart Hine who came up with the Pentroller for use with coreless motors.

 

Don

[Andy Reichert]

Is this thread for real?

 

Andy

[Donw]

Is this thread for real?

 

Andy

 

What are you doubting?

 

Don

[Andy Reichert]

What are you doubting?

 

Don

 

1. The slew of Videos/Images that are marked as deleted.

 

2. The concept of pass this around but don't publish it. (how can that happen?)

 

3. The idea that two different folk invented it.

 

4. The historical fact that "Wireless World" published a simple feedback controller circuit for N scale somewhere between 1965-70, and that literally dozens of circuits appeared later that built on it's ideas and disclosures. So how can this be "confidential" or restricted in any way?

 

Andy

[Donw]

To answer your points,

 

1. Jim's membership with RMweb has closed

 

2. Brian didn't wish it to be published. that was his request. If you have a copy you could ignore his wishes but I and many others would think of any one who did that as not a worthwhile person.

 

3. If you read it properly Jim states clearly it was Brian's design.

 

4. True there are plenty of designs of small controllers use one of them if you wish. They may substantially be very similar. This happens to have been developed by Brian from his knowledge of electronics rather than based on someone elses design.

 

If you find the idea of not publishing a circuit design unacceptable I suggest you go elsewhere.

Don

[gormo]

To answer your points,

 

1. Jim's membership with RMweb has closed

 

2. Brian didn't wish it to be published. that was his request. If you have a copy you could ignore his wishes but I and many others would think of any one who did that as not a worthwhile person.

 

3. If you read it properly Jim states clearly it was Brian's design.

 

4. True there are plenty of designs of small controllers use one of them if you wish. They may substantially be very similar. This happens to have been developed by Brian from his knowledge of electronics rather than based on someone elses design.

 

If you find the idea of not publishing a circuit design unacceptable I suggest you go elsewhere.

Don

 

 

Well said Don.

Cheers Gormo

[Andy Reichert]

I know nothing of the design, nor have a copy, nor as a EE, wish for one, so any implied admonition is premature.

 

My first astonishment stemmed from posting about a circuit, without disclosing it. There is no difference between permitting circulating a circuit diagram without a prior confidentiality agreement and publishing it. It's gone into the public domain either way. One could easily add a "not for commercial use" line to it to emphasize the intention. Although a (valid) patent would be the only practical way to enforce it.

 

As to it not being similar to or derived form earlier work. In my related professional experience, that's pushing mystique and credibility much too far. Simple PWM, with or without Feedback, designs that have been in existence for 50 years and yet are still both secret and so brilliant as to be of unique value don't exist.  Just about every possible method of PWM and/or bemf control has already been incorporated in component designs, in and/or with general integrated circuits and now most DCC decoders as well

 

And that's without considering all the commercial and cheap and cheerful hobby robotics motor control designs with similar needs that have been developed over the past 20 years.

 

Andy

[Donw]

I think you must be under an illusion about the aim of this thread. It was never intended to be a 'this is a great must have circuit' . Jim started a thread about his model railway which also appears at exhibitions. The controller he used was mentioned and people expressed an interest. In order to avoid cluttering up a thread about the layout, Jim started this one about the controller. Jim is a helpful and enthusiastic chap and wished others to benefit but also being a gentleman he respected the wishes of the designer. This seems to be an alien concept to you.

 

Your comments about their probably being many similar circuits some of which may well be superior to this one. However your suggestion that it must be derived is eroneous. True the concept of using a series of pulses and varying the pulse width instead of varying the voltage was well known, but before the internet it was common for those with the knowledge to simply design a circuit they needed. Rather than looking for someone elses circuit to copy or adapt, you just worked out one for yourself. I designed some for myself as did others.

 

Since you appear to know of so many good designs for such a circuit I suggest you start your own thread publish a suitable diagram and offer the support and guidance to others. Do at least acknowledge where the circuit comes from.

 

Don 

[CourthsVeil]

There are some readers who asked for detailed info (circuit diagram etc.) about Brian's controller.

With the promise to report on their progress and the behaviour of their controllers.

And they seem to have got such info.

 

I'm wondering why there's no response from them.

 

Too complicated the project, no success, no improvement over other gadgets, or what…?

Regards

  Armin

[kevinlms]

There are some readers who asked for detailed info (circuit diagram etc.) about Brian's controller.

With the promise to report on their progress and the behaviour of their controllers.

And they seem to have got such info.

 

I'm wondering why there's no response from them.

 

Too complicated the project, no success, no improvement over other gadgets, or what…?

Regards

  Armin

Yes, an all too common result. OK, sometimes we all forget to respond (of which I'm doubtless guilty), but does it seem that sometimes everyone fails to respond?

 

I've previously provided a free, full version of a project I've worked for a good while, on the basis they take a look & provide feedback - any feedback. When I remind them of this obligation - a few  weeks later, they tell me that they haven't even loaded it (from a CD), let alone provided a review.

[Andy Reichert]

I think you must be under an illusion about the aim of this thread. It was never intended to be a 'this is a great must have circuit' . Jim started a thread about his model railway which also appears at exhibitions. The controller he used was mentioned and people expressed an interest. In order to avoid cluttering up a thread about the layout, Jim started this one about the controller. Jim is a helpful and enthusiastic chap and wished others to benefit but also being a gentleman he respected the wishes of the designer. This seems to be an alien concept to you.

 

Your comments about their probably being many similar circuits some of which may well be superior to this one. However your suggestion that it must be derived is eroneous. True the concept of using a series of pulses and varying the pulse width instead of varying the voltage was well known, but before the internet it was common for those with the knowledge to simply design a circuit they needed. Rather than looking for someone elses circuit to copy or adapt, you just worked out one for yourself. I designed some for myself as did others.

 

Since you appear to know of so many good designs for such a circuit I suggest you start your own thread publish a suitable diagram and offer the support and guidance to others. Do at least acknowledge where the circuit comes from.

 

Don 

 

I would suggest that's what MERG is for and very good at. Sending it to them would achieve all the objectives in one simple step.

 

Andy