Large Scale Central

Fuses using battery power?

Electronics Power and Sound
#1

Just had a thought after posting about my dead-reborn Crest Rx. Should I place a fuse between my loco batteries and the Crest Rx’s? If so, what rating do people generally use. I know it would vary according to Loco, train weight etc. Just wondering what people think on the matter.

I only started with battery last year

Mike

#2

I use a 5-amp fuse in my installations. I put it between the power switch and the electronics. Cheap insurance, and depending on the form factor of the fuse, it doesn’t take up a whole lot of space.

Later,

K

#3

Depending on how the battery circuit is wired I find it safer to put fuses between the battery pack and the first place where a switch might change it’s status. That way the battery is also protected from overload charging.

#4

Thanks for the advice Tony. I’m going to add a fuse today.

Mike

#5

I have added Polyfuses to several conversions. They can be wired in parallel and are self-resetting after you remove the short. Easier than taking the loco or tender apart to change the fuse.

#6

Thanks Pete

Do you have a part number? - and even better, a schematic?

Mike

#7

Trainli has 3 amp poly fuses available. These are surface mounted devices and we even have a small circuit board to mount them on.

#8

Mouser Electronics has the 2.5 amp self-resetting fuses under stock number 576-30R250UU.

SELF RESETTING FUSES

#9

Mike Lafferty said:

Thanks Pete

Do you have a part number? - and even better, a schematic?

Mike

Mike,

I bought a bag of them 20 years ago - still have some a lot left. The bag says All Electronics, part RXE-065, which is still on their website:

http://www.allelectronics.com/make-a-store/item/rxe-065/resettable-circuit-protector-0.65-1.3-amp/1.html

Not sure what kind of schematic you are looking for. They are essentially 1 amp fuses, and you can set up multiples in parallel for higher current values - e.g. use 10 for a 10 amp loco. (Yes, I know they trip at 1.3 amps, but for our purposes it doesn’t matter as long as they trip before the wiring melts!)

Chapter and verse is in this doc:

http://www.littelfuse.com/~/media/electronics_technical/application_notes/resettable_ptcs/littelfuse_polyfuse_ptc_selection_guide_application_note.pdf

#10

The surface mounted ones at Trainli are much smaller than the ones pictured above.

I tied 2 together in parallel yesterday and they increased in resistance at 5 1/4 amps.

#11

Pete Thornton said:

Mike Lafferty said:

Thanks Pete

Do you have a part number? - and even better, a schematic?

Mike

Mike,

I bought a bag of them 20 years ago - still have some a lot left. The bag says All Electronics, part RXE-065, which is still on their website:

http://www.allelectronics.com/make-a-store/item/rxe-065/resettable-circuit-protector-0.65-1.3-amp/1.html

Not sure what kind of schematic you are looking for. They are essentially 1 amp fuses, and you can set up multiples in parallel for higher current values - e.g. use 10 for a 10 amp loco. (Yes, I know they trip at 1.3 amps, but for our purposes it doesn’t matter as long as they trip before the wiring melts!)

Chapter and verse is in this doc:

http://www.littelfuse.com/~/media/electronics_technical/application_notes/resettable_ptcs/littelfuse_polyfuse_ptc_selection_guide_application_note.pdf

Thanks for the info Pete.

Sorry I got confused when you mentioned putting them in parallel. Tha’ts why I asked for a schematic. I stoooopidly thought you installed the fuses across the pos/neg instead of using multiple fuses in parallel(to increase rating) in line with the positive line from the battery.

This type seems the way to go for sure!

Thanks

Mike