Looking for fuse/breaker suggestions

The most recommended TVS around here seems to be the 1.5KE36CA. I don't think Radio Shack has them. I would recommend Digi-Key, and use their USPS first class shipping, great place and very fast and reasonable on shipping.  Link: Digikey TVS 

 

As for the breaker, the PSX-AC is probably the best available for our trains, but also a little pricey. You can get them from Charles Ro a little cheaper, but Tony's Train Exchange will provide support if you have problems (at least they advertise that anyway). Many here recommend breakers available from marine supply stores. I thought I had one marked, but I can't find the link. Anyway they were more reasonably priced. Dale H has posted a breaker he has used on his blog.

 

I will try to find my link to those breakers and add to this post if I find it. I see Dale H posted the link for the breakers below.

 

I would personally prefer the PSX-AC's for the modern electronics in our newer trains. The cost of replacing an engine makes the PSX-AC price look a lot better. I have the PSX-AC's with the Powerhouse 180's on my TIU. The PH-180's have excellent breakers also.

Thanks  to both of you.  I'll be putting in an order tomorrow.  In the meantime its back to conventional running with an MTH z750!

Good luck with your selections. If you like the PSX's, or want more info, here are a couple of links I left out of my previous post. There are also some threads here on the forum about them, search for PSX.

 

PSX1-AC - Tony's

 

PSX1-AC - Charles Ro

 

At Charles Ro they are under - O Gauge - Lionel - Legacy and Trainmaster - on the bottom of the last page there.

 

Train Electrics also has regular breakers - Circuit Breakers. Was thinking of this earlier and couldn't remember their name. Theirs are similar to the ones Dale H linked to.

 

I have used Raychem Polyswitch resettable circuit protectors throughout my layout to protect power supplies and transformers. They work wonderfully and are really inexpensive compared to circuit breakers. Available from most electronic supply houses.

Using standard AGC automotive fuses, no more the 8 amps per track circuit.

Grainger Supply.  Click on the underlined phrase to link.  Fuses can be purchased in different amperages at local auto parts stores.

Hi Bob,

Can you supply a link for the Raychem protectors? I'd like to try that, but I can't seem to find them anywhere on line. What amperage do you use?

 

Thanks,

George (G3)

Try going to Mouser Electronics as they have both the TVS units and circuit breakers that you will need. www.mouser.com

Get the 32 volt bi-directional TVS unit. A 7 or 8 amp circuit breaker should be the correct size to use with a KW. The 7 amp circuit breaker part number is: 691-CMB07311C3NBA (Mouseer part #) or mfg part number: CMB-073-11C3N-B-A

 

I have the 7 amp breaker from Mouser as that is what is on the MTH Z-1000. Not that same breaker number but rating.

May have the TVS part number some where around the house as I bought them a few years ago from Mouser. The price is way less from Mouser then if you buy them assembled in anything such as Scott's Odds and Ends or other companies.

 

Lee Fritz

 

 

 

The generic name for this component is Polymeric Resettable Overcurrent Protector. They look like ceramic capacitors and work like a fuse except you never need to replace them when they trip. They come in a large number of hold and trip currents. Depending on circuit current demand, I have used a 1.3 amp trip unit and a 4.0 amp trip unit. Some manufactures of this type of device are: NTE, Tyco Electronics, Bourns and Littlefuse. DigiKey elelectronics has a large selection at many current carrying levels and All Electronics stocks one current level. Hope this helps.

Bob,

Which Raychem polyswitch resettable circuit protector did you use, interested in the hold current and time to trip?. I checked Mouser and DigiKey in the past for these semiconductors and compared the trip times and hold currents, since you used them successfully and have a history your response would be appreciated. I will be operating and TMCC modes, with the exception of two post war Lionel engines with the open frame AC motors, all other engines(MTH,AtlasO,Williams and K-Line) have DC can motors. I was considering a 6 Amp hold and shortest trip time, these semiconductors are great because they self reset as the current drops to the hold current and are not expensive. My concern is to prevent electronic board damage from over current surges.

I use TVS diodes and a redundant system of breakers with 5 amp marine breakers along with PTC fuses. I started with much higher breaker amperage and experimented with smaller ones and settled on 5. I feel that the closer you are to capacity, the quicker they throw when needed. At 5 amps on my layout per channel on my ZW, I don't get premature trips, but they tip quickly on derails. They generally trip sooner than my PTCs.

 

Roger

Good idea to have TVS diodes also as you and others suggest, can't hurt having too much protection.  I have looked at some of the breakers on Digi-Key, Mouser and elsewhere, but never thought the trip times were very good. Using the lower amperage ones appear to give better trip times in their ratings. I think a fast blow fuse would be much better, although I know they are a pain to keep replacing. I have not tried the PTC's or looked into the lower current rated items.

 

The slow trip times are why I prefer the PH-180 breakers, some TVS diodes and/or the PSC-AC's. I went with all of them, PH-180's, TVS's and PSX-AC's. The PSX-AC's are cheap when compared to replacing the electronics in just one engine. Replacing the electronics in just one engine would probably get you about 4 or 5 PSX-AC's,depending on parts used. More if you don't do the work yourself.

Re the PTC s, download the data sheets from digikey, and you'll find the hold currents, trip currents, and trip times.

As I am a EE, I test every component I use in my layout. Before I used the Raychem resettables, I ran some tests. The current shutdown action was almost instantaneous as far as I could tell, so I went ahead with their useage. The only two levels I've used so far are 1.3 and 4.0 amps trip currents. Remember that an overcurrent problem takes a certain amount of time to do any damage. A transient voltage spike, on the other hand, can cause an immediate failure of a circuit component.

Bob with you response on the Raychem resettables and Dewey's response on the TVS, I am going to use both semiconductors on my layout.

 

John

I looked on the Raychem website and it appears that they make the pretty standard PTC devices, and the trip time is really not that super fast, nothing like a quality electronic circuit breaker, or even a thermal breaker.