DCC Power Unit.

[Chrissaf]

You must not really exceed 5 amps for the PSU. Yes the Hornby DCC controllers [select eLink and Elite**] are designed to trip [when a short circuit occurs] at 3.5 amps which leaves a 0.5 amp overhead with the supported 4 amp supply. The risk of the short circuit protection circuits failing (unlikely, but possible because of the capacity of your proposed PSU to instantaneously being able to supply more than 30 amps, before their protection kicks in) would open up the possibility of your controller melting and passing 30 odd amps to the track. In my view the risk although marginal is still too high. Remember, that to supplement the internal short circuit protection, the Hornby 4 amp power supply will have its own 'overload' protection to kick in at 4 amps. Your proposed power supplies won't be at all stressed at 4 amps and won't go into shut down until the current exceeds their rated configuration i.e 30 amps plus.

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Note** when the Select and the eLink are powered by the Hornby 1 amp supply [which of course is less than the configured 3.5 amp trigger value] the 1 amp PSU is relegated to performing 'short circuit' protection. In other words, it is the 1 amp PSU that shuts down under a short circuit condition.

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PS - I have posted a follow-up 'for your information' post in your "What have I said" thread. No indication as yet that you have seen it.

[Chrissaf]

Reading through the Hornby literature, mention is made of higher capacity (4 amp  IIRC) power units

needed to run larger layouts and more current consumers...

This will probably not affect me for some while, but having been a Radio Amateur for 30 years or so, I have accumulated several  0 to 15V  DC power units capable of 35 to 40 amps.

Would it be worth allocating one for 00 gauge use in the future?

 

Roger/Chalford

[Roger1707821911]

Thanks for the response and I do take your point (no pun intended).

This would preclude two of my PSUs for the reason you state, but the third one (IIRC) is Lab standard and has

"Max Current " limiting potentiometer variable from 0.1A to 35A..  so might be usuable?

 

Thanks for the update on the other thread.....I,m sure that I would not have suspected that particular word....maybe

I should get out more!!!

 

Regards  Roger

[ColinB]

Ok, if you are really worried put a 4 amp fuse in the lead, we are only talking 12 to 16 volts. I cannot remember if my Elite has a fusable link on its input, it should have seeing as Hornby cannot guarantee which power supply you are going to attach. Actually if the short circuit system failed you have real big issues anyway, I think you will find the circuit board drivers will fail before it draws the maximum current. Now over voltage is a different issue.

[96RAF]

Elite has a couple of PTCs (self resetting fuses. One is 3 amp (DC in) and the other is 1.1 amp (Boost-Prog out).

[ColinB]

Thank you RAF96. so actually you can use any supply as long, and a very big as long it is within the specified voltage range. The only issue is with a 30 amp powersupply if it shorts out in the plug it will probably melt the connector and possibly what it connects to, but most power supplies have trips. As Chrissaf says user a smaller one if only for the fact it is easier to manage (not so heavy). I think I run my Fleishmann on an old laptop supply.