Help,I think I fried my Railsounds in my Legacy Ten Wheeler!

The guy you bought them from has one more TMCC rig, then a ProtoSound 1 board set left.

Actually MTH installed TVS's in their DCS TIU/AIU system after I supplied them with the information on surge protection during the design stage for their system. They decided that that was all that was necessary and never installed them in the engines themselves.

So, I guess if you operated MTH PS2/3 engines with their DCS system you might be safe.

Since Lionel boards could withstand 50 volt surges versus 35 volts for the original QSI P1 boards, this according to surge testing done by QSI in 1999, I guess they thought that they did not have to do anything.

gunrunnerjohn

The EEs[Bob Nelson and Dale Manquen are two] have told us that voltage spikes emerge from the transformer itself which indicates to me that the first line of defense against voltage spikes is to wire a TVS on the transformer or on a location such as a terminal strip or the track itself downstream from the transformer output.

You advocate installing TVS in the engine [and/or tender]which being a conservatative in the belt and suspenders mode I agree with. However,at the same time I realize that the average O-gauger will not, or cannot, deal with opening an engine and perfoming the task, in particular on multiple electronic equipped engines. [myself, I am at an age/health were hand tremors prevent me from doing that type of work].

We were told on the Forum way back in the day that a key reason for installing a TVS is that voltage spikes will not trip a circuit breaker as does an over-current surge. In my own long ago experience I know that one reason we synchronized generators when paralleling was due to component damage from high voltage because the breakers did not trip upon over-voltage from one of the sources.

Question:

In your post above you raise the risk of damage still being done to engine circuitry by an event such as the overcurrent surge created upon a derailment downstream from a TVS. Are you saying that a TVS in the engine will prevent an over-current surge caused by a deraillment? Or, are you saying that the surge event downstream will itself cause a damaging voltage spike to emerge?

I don't want to get Rich on my case for starting a ultra tech discussion. I am simply interested in whether you believe a much higher degree of risk for electonic component damage is an exposure by not having a TVS in the engine, only on the transformer?. A key question I believe because I think most of us will not have TVS installed in our older electronic equiped engines.

Thanks.

I guess you should explain that you can't damage Lionel electronics to the folks here that have a derailment and lose a board.

While many (most) voltage spikes are indeed originated at the transformer, I don't disagree with that.  I totally agree that the track feeds should have a TVS, no argument there.

However, there's a few things left out of the reasoning.

While that will go a long way toward protecting the layout, consider the distance from that TVS and the RF impedance of a long run of track and/or power feed to the track.  The transients we're most concerned with are nanoseconds in duration.  Any inductance can induce a voltage spike as the connection is broken, it's why many relays are fitted with diodes across the coil to snub the spike.  The very process of the connection breaking as your derailment happens creates an arc there certainly generates transients of unknown amplitude.  While any spike may be suppressed on the track side, depending on the inductance between the derailment and the TVS at the track feed, it's not necessarily suppressed on the other side of the arc, that being the engine or tender.

The absolute best place for the transient protection is at the device being protected, in this case it's the electronics in the locomotive and tender.  In addition, if you take the locomotive to another layout that's not so well protected, you have your own transient protection with you.

That's this EE's opinion, others are free to disagree.

john at the time he had 4 of those TAS boards and a QSI three boards set...everyone starting bid at 19.00 buy it now for 60.00 with 2.00shipping..Im glad id scooped mine up because after 15-20mins the rest where gone too...John are you looking for a proto1 set?..If so hit me a email.

Oh I forgot..what about running a surge protecter ? like the ones that QSI has out..transformer hook to it....Then the track wires goes to the qsi surge protecter...

Nope, don't need no Proto1 boards.

Don't know what "surge protector" you're talking about.

like this one and theres a digital version too.i think?

http://www.the-scaled-tin-rail...therqsiproducts.html

Thanks for your response John. No argument from me. It seems to me that you do believe engines are still at risk without a TVS in the engine. Not good news for the horde of TMCC and DCS operators that will only be protected at the source-hopefully even that?

joseywales

I still have those[costly back in the day--about $80] PowerGuards wired. I like to see the lights flash upon minor spikes. But for better protection I have TVS wired on the TPC terminal boards linking my PoHos.

I sent Dale Manquen one I had removed from a dismantled layout for his tear down and evaluation. He concluded we should use the TVS as superior protection versus the PowerGuard.

never hurts to add extra protection to your train..dont know why o gage has more proublems with surges then guys that have DCC and the HO guys that are running DCC..

If you need the bells and whistles, no pun intended, just go to this site and there are detailed instructions on how to build a device that indicated when there is a voltage spike.

http://www.hirailers.org/