hi everyone. for the past few months, i have been trying to figure out how i can safely run my new electronic trains with an old 275 watt ZW and a KW. i tried TVS, but it shorted and the diode broke in half, i tried 8 amp breakers but they are to slow, and i read that the TMCC lockon with fast acting breaker only works with command control! I dont want a new transformer because i just got my ZW restored. thanks
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What TVS did you try? The 1500W 33.3V TVS at Digikey is widely used for O-scale model trains, including at my layout, and they don't routinely die. If you're truly concerned about fast circuit protection, consider the PSX-AC on each track feed.
GRJ--are you thinking that the PSX1-AC is fast enough to protect the loco electronics in the event of a derailment short?
Don Merz
Well, there's nothing that's absolute protection in the event of a derailment. All you can hope for is to minimize the damage window. The faster you remove the power, the better chance that you'll stop the bleeding before it bleeds to death. 
For electronics protection it doesn't get much better than using the two items GRJ pointed out above. I'm a big fan of the PSXs, had them for several years, haven't blown anything yet.
@gunrunnerjohn do i have to buy 3? one for each track? I have a doubletrack mainline and a yard.
ok $0.68 vs $50. i'm completely lost here. Sorry.
@Matt Bollinger posted:@gunrunnerjohn do i have to buy 3? one for each track? I have a doubletrack mainline and a yard.
You are protecting transformer feeds, so one for each separate transformer output.
@TomSuperO posted:ok $0.68 vs $50. i'm completely lost here. Sorry.
The two work in conjunction, so you need both for the best protection for each transformer output.
Correct me if I am wrong, but my understanding is that ALL models of the MTH TIU already have a TVS on the output? Or input? Somewhere anyway...
Don Merz
Correct, the TIU has a suitable TVS on each output.
Has anyone gone stone crazy enough to measure the reaction times (to a short) of the PSX1-AC versus the breaker already on the PH180 transformer? Or a fuse? Or a modern circuit breaker? The money IS an issue. I have 8 blocks. This thing PSX1-AC is selling for $60 shipped per unit. So I would be at $480 to protect my layout. OTOH, $480 could be the repair bill on one loco, right? Sigh....I ordered one to test it.
Don Merz
Well, the PSX-AC is solid state switching, so in theory it could interrupt power in microseconds. The PH180 has electronic sensing, but a relay is actually used to interrupt the power, so it's reaction time is probably a few milliseconds.
I don't really know if the difference is all that significant as far as failure rates of locomotives is concerned. I personally consider the protection of the PH180 circuit breakers sufficient for my use.
Are the TVS and PSX-AC protection recommended for the new ZW-L or just the older ZW?
Well, I'd add the TVS, I don't know about the level of protection for the ZW-L, so I don't know if you really need the PSX-AC as well.
@gunrunnerjohn posted:Well, the PSX-AC is solid state switching, so in theory it could interrupt power in microseconds. The PH180 has electronic sensing, but a relay is actually used to interrupt the power, so it's reaction time is probably a few milliseconds.
I don't really know if the difference is all that significant as far as failure rates of locomotives is concerned. I personally consider the protection of the PH180 circuit breakers sufficient for my use.
I've never had an issue with the circuit breakers on my PH180s letting anything die. I also don't see the need to add a PSX-AC in front of them.
To be honest most failed modern circuit boards I've seen have been caused by the combo of Postwar ZW and no other circuit protection.
For over two decades prior to installing 2 PH180's i ran my layout on 4 Lionel LW transformers with a TVs on each output. Now both PH180's have a TVS on each output. Never had a problem in either instance in a total of over 30 years of running.
@Matt Bollinger posted:hi everyone. for the past few months, i have been trying to figure out how i can safely run my new electronic trains with an old 275 watt ZW and a KW. i tried TVS, but it shorted and the diode broke in half, i tried 8 amp breakers but they are to slow, and i read that the TMCC lockon with fast acting breaker only works with command control! I dont want a new transformer because i just got my ZW restored. thanks
Not sure where you read that the TMCC Lockon only works with command control. It can be used just fine with a ZW, with a Power Adapter Cable. See the Lionel Lockon instructions as shown below. Personally, I'd just use a Lockon with the Power Adaptor Cable and be done with it. The Lockons work great - I've used one for years.
"You also have the option to use a Power Adapter Cable (6-12893) that allows you to use any transformer, such as a CW-80 or a Post-War ZW, with your TMCC Direct Lock-on instead of a PowerHouse Power Supply. Follow these steps to connect the cable and refer to figure 2 on page 5. (Etc. - instructions go on from there)
@breezinup posted:Not sure where you read that the TMCC Lockon only works with command control. It can be used just fine with a ZW, with a Power Adapter Cable. See the Lionel Lockon instructions as shown below. Personally, I'd just use a Lockon with the Power Adaptor Cable and be done with it. The Lockons work great - I've used one for years.
He probably read it because I posted it! Below about 12 volts the TMCC Lockon no longer functions. It really is intended for command operation, hence the name TMCC Direct Lockon!
@gunrunnerjohn posted:He probably read it because I posted it! Below about 12 volts the TMCC Lockon no longer functions. It really is intended for command operation, hence the name TMCC Direct Lockon!
OK. Thanks.
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