To put in a TVS or not

On this forum's advice I added them to my layout wire plan 2 yrs ago when I was doing the wiring.  Plenty of small sparks/shorts etc since then and no blown boards on any of the engines.  I think it was good advice back then and is still solid.  

@42trainman posted:

On this forum's advice I added them to my layout wire plan 2 yrs ago when I was doing the wiring.  Plenty of small sparks/shorts etc since then and no blown boards on any of the engines.  I think it was good advice back then and is still solid.  

And very simple just across the incoming feed to the boards………again a big thank you to John

@42trainman posted:

...Plenty of small sparks/shorts etc since then and no blown boards on any of the engines...

You may have experienced the same results to this point even w/o the TVS didoes, but the damage is cumulative... so the question becomes when will the electronics fail. TVS diode usage will certainly extend the MTBF hopefully long enough to last your lifetime.

@ADCX Rob posted:

You may have experienced the same results to this point even w/o the TVS didoes, but the damage is cumulative... so the question becomes when will the electronics fail. TVS diode usage will certainly extend the MTBF hopefully long enough to last your lifetime.

Very true, I also changed out the TVS when making the repair on the truck. It tested ok but I have a box of them and they are a cheap preventive to add.

Once I finish wiring up my Conventional Power Layout that I have TVS on all Transformers Outputs and Track Feeder Connections I will be installing them in all my Locomotives for even more protection of the boards.

Please send link the best article(s) on using TVS

@Windy City posted:

Please send link the best article(s) on using TVS

Some guys install the TVS on the power supply to the tracks, I prefer in every locomotive this includes the tender on a steam engine. Find the wires in the engine that come from all pickups and chassis ground. The put the TVS across them, the digi-key part number is  1.5KE39CALFCT-ND the manufacturer part number is 1.5KE39CA This is for a TVS Diode 33.3VWM 53.9Vc DO201

I've had mixed results in installing TVS's in my RailKing PS1 and PS2 locomotives. In many cases they work just fine, but in many other cases they cause the horn to sound continuously.

The only way to get the horn to shut-up is to disconnect the TVS from the wire nuts where the track power (red and black wires) is connected to the circuit board.  Go figure!!!!

So some of my engines have the TVS protection, and some don't.

Can someone please tell me what I'm doing wrong????

Peter.....Buco Australia.

Are you sure you're using the right TVS?  If you're not using the bipolar TVS, you can get those results.  A polar TVS (with a stripe), is incorrect for AC use.

This is the correct TVS for O-gauge use: 1500W 33.3V TVS at Digikey

@ThatGuy posted:

...I prefer in every locomotive this includes the tender on a steam engine...

This is a good idea to alleviate concerns when your equipment visits other layouts.

@ADCX Rob posted:

This is a good idea to alleviate concerns when your equipment visits other layouts.

Yes Sir………..these toys are too expensive to leave to chance

@gunrunnerjohn posted:

Are you sure you're using the right TVS?  If you're not using the bipolar TVS, you can get those results.  A polar TVS (with a stripe), is incorrect for AC use.

This is the correct TVS for O-gauge use: 1500W 33.3V TVS at Digikey

Yup here is the slip

Thanks Gunrunnerjohn:

Here is a photo of the TVS units I have been using, and their ID issued by "Element 14" - the major electronics supplier here in Australia.

Are they correct????

Peter......Buco Australia.