Search found 109 matches

by fourtytwo
Thu Apr 02, 2020 6:54 pm
Forum: Electronics
Topic: Control panels. Show us yours.
Replies: 5
Views: 569

Re: Control panels. Show us yours.

Here's mine, traditional switches on diagram for points and sections with lines colored to correspond with controllers, very simple compared with some in the past as I decided to go back to basics with this layout (human controlled). P1130867.JPG P1160317.JPG It's fixed to the layout with hinges all...
by fourtytwo
Thu Apr 02, 2020 6:44 pm
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Hi Albert Could I get away with using an S8050 instead of the 2N3906? I just want to crack on rather than waiting for the postman, as I understand that parcels are travelling slowly at the moment, and I have all the other components in stock I am sorry Albert, it has to be PNP, all your transistors ...
by fourtytwo
Wed Apr 01, 2020 7:18 pm
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Thank you Albert for your kind comments, it is nice to be able to help someone in the same hobby. I am afraid the 2K2's in the above diagram don't do quite what I had intended as your L293's are never truly off (tri-stated) unless the EN pin is driven low. Another alternative to provide a small resi...
by fourtytwo
Wed Apr 01, 2020 3:03 pm
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Hi Albert I have tried to capture your system including the L293's and the power supplies in the diagram below for both the uni & bi directional situations. If these make sense to you (\/ symbol is 0V) then I will draw just whats inside the Trkckt box. There are some things on your circuit diagr...
by fourtytwo
Wed Apr 01, 2020 9:30 am
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Hi Albert I foresee a potential problem in your application and that is these track circuits are designed to be used in a common return system where the common return is system ground. The first important point is the track circuit bias must always be +24V relative to common return. The OCC signals ...
by fourtytwo
Tue Mar 31, 2020 7:07 pm
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

I found the quality issue, it was in color, I have now printed it in monochrome and it seems much better. The original diagram was done over a year ago and either I had run out of color ink or some other reason printed it in monochrome and I eventually figured that was the difference :oops: Anyway i...
by fourtytwo
Tue Mar 31, 2020 12:22 pm
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Hi Albert, great!! So do you have another 12V wallwart you could add in series with the first to make a 24V bias supply ? In any case here is a drawing assuming just that, the controller has been replaced with a PWM like your arduino and the NPN transistors with your 2N2222's, note the PNP is a comm...
by fourtytwo
Tue Mar 31, 2020 9:32 am
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Hi Albert A capacitor might absorb some of the aggressiveness as would a series inductor. If you had access to an oscilloscope you could check the risetime and/or the peak current. Otherwise check your loco tyres under a magnifier. In the meantime I am afraid I still don't know what the operating vo...
by fourtytwo
Mon Mar 30, 2020 4:58 pm
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Hi Albert, thank you for the replies, may I ask what gauge your running (just for an idea of motor currents) ? The detector needs a bias supply 5-10V higher than the PWM supply voltage Depending on the PWM frequency you may need synchronous detection, meaning the OCC signal will only be high when th...
by fourtytwo
Mon Mar 30, 2020 9:41 am
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Sorry Albert I was not sure if you made your own arduino circuits. I can customise this for you if you tell me Is your arduino 5V or 3V3 (or what is the part number of the chip) ? What controller do you use for your railway ? What transformer secondary voltage you use for the controller ? Do you hav...
by fourtytwo
Sun Mar 29, 2020 12:06 pm
Forum: Electronics
Topic: Track Circuits (Train on Track Indicators.
Replies: 42
Views: 2474

Re: Track Circuits (Train on Track Indicators.

Hello Albert I don't know how much you like tinkering or burning your fingers but here is a simple 3 transistor circuit I have used for years, it is bi-directional and is easy to adapt for different voltages etc. The supply to a section passes through a diode and the voltage across the diode is sens...
by fourtytwo
Sun Oct 27, 2019 10:18 am
Forum: N Gauge Model Railway
Topic: Signalling at Riccarton junction
Replies: 0
Views: 1413

Signalling at Riccarton junction

Riccarton was constructed several years ago but lacked signals, given it is a steam era layout I seriously wanted to use semaphores however this proved impracticable as IMOP the ratio products are to flimsy and the Dapol uneconomic. I eventually decided to use two aspect color light to represent sem...
by fourtytwo
Thu Oct 03, 2019 7:09 pm
Forum: N Gauge Model Railway
Topic: operating Ratio Semaphores
Replies: 6
Views: 1441

Re: operating Ratio Semaphores

I am sorry to report I have thrown the towel in regarding working N gauge semaphores at least using the Ratio kits, they are just too fragile IMOP and the clearances are just not there for the operating wire at least in the lower quadrant variety and I was experimenting with a simple straight post, ...
by fourtytwo
Fri Sep 13, 2019 11:02 am
Forum: N Gauge Model Railway
Topic: operating Ratio Semaphores
Replies: 6
Views: 1441

Re: operating Ratio Semaphores

Thank you for the replies, dammit I should have used the word pivot but had brain blockage at the time! I didn't have a problem with the pivot being free although I constructed them many years ago so I am not sure how. The problem is the location of the operating hole in the arm, it means any wire w...
by fourtytwo
Sat Sep 07, 2019 6:43 pm
Forum: N Gauge Model Railway
Topic: operating Ratio Semaphores
Replies: 6
Views: 1441

operating Ratio Semaphores

I have gotten down to signalling on my steam era layout Riccarton Junction and am determined upon semaphores but don't have the budget for Dapol etc. I have some kit built GWR ratio's that I never got operating, however the arms move freely. As supplied there is an operating wire hole between the fu...

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