Frog alert!

On my layout I have a couple frogs at the beginning and end of a gantlet track over the Rockfish River bridge. Often when I run a locomotive through one of the frogs the PSX circuit breaker will trip. This is not consistent, only when a locomotive has passed in the opposite direction. So what is going on? Well first, I have the frogs protected with Frog Juicers. These Frog Juicers are a great option for controlling the polarity of turnout frogs in a situation like this one where a switch machine is not used. These small electronic circuits sense when a locomotive’s wheels contact a turnout frog and the polarity doesn’t match. In this situation the circuit automatically corrects the frog polarity before the booster short circuit detection kicks in.

But why did I get a short only after a locomotive passed in the opposite direction. Well that locomotive tripped the Frog Juicer resetting the polarity. So when the next train came from the opposite direction the polarity was incorrect, tripping the PSX and resetting the polarity. This flip-flop went on until I found out that the PSX was tripping before the Frog Juicer could do its thing–why? Actually, the Frog Juicers are (electronically) very slow. The default trip time on the PSX is about 3ms making it faster than the Frog Juicer, so it will trip first. So how do you fix this? On the PSX set CV55=1 and CV65=128, and the PSX delay will be slower and should work with the Frog Juicers.

6 comments

  • Hi Larry- I missed seeing the camo frog at first and thought you were equating track frogs to string beans. I figured it out and had a good chuckle. Thanks for it.
    Robert

    • That little guy lived in our water garden and sang every night from June into August last year. There were actually three of them trying to lure in some females for fun and games.

      • So, how did they do?

        • Unfortunately no, with one exception. I did find one egg mass but the current in the stream was too fast and they were washed away. I put branches across the stream in the fast water to give them anchor points for the eggs but they didn’t use them. Maybe next year.

  • Thank you as I, and many others from the Mag Blogs I read, have this problem.
    Tam Valley had me by-pass the PXS, but this didn’t totally solve the issue to my
    disappointment. Hopefully this will solve things.

    • By the way, I got this information from Larry Maier, the developer of the PSX circuit breakers and various other DCC Specialties products. If the delay value I gave doesn’t slow down your PSX enough then you may need to experiment with values that lengthen it even more. It really is a balancing act since the PSX is designed to be a fast trip circuit breaker instead of a slow blow fuse. Here is the full info on adjusting the response time.

      Changes for PSX Rev K and PSX-AR Rev N:

      Place the unit in the program mode and turn it on. D6 will flash the Morse code pattern of the software revision letter. The PSX breaker will flash long-short-long (K). The PSX- AR will flash long-short (N). This revision of the PSX series creates the ability to insert a delay in the reverse action of the PSX-AR (and hence a delay in the breaker function also) and in the breaker action of the PSX. To enable the delay, set CV55=1. The length of the delay is set by CV65. The value in CV65 divided by 8 is the length of the delay in milliseconds. By default, CV65 is set to 24, or 3ms. CV65 can be set to any value between 1 (0.1 ms) and 255 (31.9ms).