DAPOL - YOUR THOUGHTS ?

[Dr Al]

A lot of the cheap diodes LED and signal sourced in China are poor clones and way off the advertised specs.  You can bet the factory is buying cheap and it does not take much of a voltage spike to fry the Anode

I can quite believe that. Seeing the capacitor arrays self destruct in clouds of smoke sitting on pure DC at half speed, showed the quality (or lack thereof) of some of the components they're using. Fortunately, those can just be removed and binned without replacement, without loss.

Cheers,
Alan

[guest311]

I'm not getting involved in this, other than to say I had a couple of class 66s which were not too good, and were sold on, but later cl. 26 / 27 seemed to work fine on Inverknockie  v 3 and 4.

so my basic thought would be that Dapol is listening, and improving.

my view from my experiences.

[Snowwolflair]

A lot of the cheap diodes LED and signal sourced in China are poor clones and way off the advertised specs.  You can bet the factory is buying cheap and it does not take much of a voltage spike to fry the Anode

I can quite believe that. Seeing the capacitor arrays self destruct in clouds of smoke sitting on pure DC at half speed, showed the quality (or lack thereof) of some of the components they're using. Fortunately, those can just be removed and binned without replacement, without loss.

Cheers,
Alan

Fortunately as I convert my locos to DCC sound I strip out all electronics except the front and back LED diode arrays and hard wire in the decoder, and I definitely remove the DCC socket.  The DCC chip will protect the LEDS especially as I slightly up-rate the protection resisters and I use lots of heat shrink.

[Train Waiting]

Never had one fail on any of mine, so not sure what people are doing to make them fail.

Likewise, and I am equally intrigued to find the actual cause.

My suspicion is that it's momentary shorts, wheels touching backs of poorly adjusted point blades etc, shorts caused by derailments, etc - the BAT54C diode package isn't rated that highly (700mA IIRC?) so a short or spike may well degrade and ultimately cook it. LEDs pretty much can only cook if overcurrent, which means over-voltage given they do have protection resistors. Not sure how that happens on DC unless it's from old controllers?

At some point I do need to sit down and work through the circuit properly, to see if the weak components could be replaced with something more robust, or reworked to be completely removed.

Cheers,
Alan

This is fascinating stuff; thank you very much. 

Best wishes.

John

[joe cassidy]

I have the following Dapol steamers :

M7
B17
A3
A4
Schools

In terms of robustness, the M7 and the B17 have hit the deck and survived with only superficial damage.

I had to replace one of the wires connecting the loco to the tender on the A4 - a test of patience.

No issues with haulage capacity or derailing, apart from the well-documented issue of the bogie on the Schools class.

I prefer the shinier finish on Farish locos and coaches but, as we say in France "chacun son gout".

Having said that, my A4 with valences in blue livery with red wheels is my favourite loco in terms of looks.

Best regards,


Joe