Large Scale Central

Bachmann K27, with battery power, radio control, and sound

Electronics Power and Sound
#1

I finally finished both articles on the Bachmann K27. The first shows how to install a Cordless Renovations lithium-prismatic battery pack and Aristo-Craft Revolution receiver. The second details the installation of a Phoenix Sound P8.

The little interface board beside the P8 sound board allows the sound volume to be raised and lowered using the Revolution throttle, and the optical chuff sensors in the cylinders of the K27 to be used with the P8. Apart from basic soldering skills, no knowledge of electronics is required to assemble the board. The chuff averaging option was activated to ensure there would not be any irregularities in the chuff cadence at any speed. The chuff sounds every 90 degrees the drive wheels turn. Overall the P8 in the K27 sounds GREAT! The deep chuff and the hand rung bell are the best I have ever heard. To view the articles, just click on the links. http://www.ovgrs.org/BachmannK27 http://www.ovgrs.org/P8SoundK27

#2

Paul.
I turn the chuff averaging off as it tends to keep chuffing after the loco has stopped.
If the chuff is not exactly 90 degrees take the cylinder front covers off and jiggle the chuff boards a bit until they seat exactly.

BTW I believe it was me that designed that chuff circuit reverser, not Phoenix.

#3

Kewl. I’ve had a couple of nice phone conversations with Doug about this. It’ll be great to see the 2 of them double heading a freight around Doug’s layout.

My battery pack was a tad bit bigger than that one, and I had to cut off one of the posts supporting the circuit board. I also took out all the weights figuring the battery would compensate for the weight. That thing weighs enough as it is.

Good article Paul!

#4
TonyWalsham said:
Paul. I turn the chuff averaging off as it tends to keep chuffing after the loco has stopped. If the chuff is not exactly 90 degrees take the cylinder front covers off and jiggle the chuff boards a bit until they seat exactly.

BTW I believe it was me that designed that chuff circuit reverser, not Phoenix.


Hi Tony!

I found the schematic on the Phoenix Sound web site, but neither Doug nor I could figure it out because it included a lot of extraneous wiring not relevant to the chuff averaging circuit. Doug remembered that you had got the optical chuff sensors to work, so we went to your web site. After seeing your picture and explanation, the light went on. We were able to exclude all the extraneous wiring. The circuit is quite simple once it is isolated; and simpler yet when placed on a straight trace perf board.

Thank you for your help! It is very much appreciated. I hope that now K27 owners will now be able to use the optical chuff sensors instead of messing with a reed switch and magnets on the tender wheels.

#5

Paul, thank you very much for this. i hated that reed switch option in my K27. I will get to work on this for mine as well.

#6

Paul,

I was looking at your install location of the battery in the tender. I was wondering if you get a balance issue with the weight of the battery on one side of the tender?

#7

Just read the install article on the k27. Where is the fuse or breaker for the MANDATORY protection for charging and running circuits for this hardware? The article picture shows wiring direct from charge socket to what is likely a 25 cent Chinese made DPDT switch, and direct out to electronics. Safety?
Jonathan/Electric /Steam Modelworks

#8
Jake Smith said:
Paul,

I was looking at your install location of the battery in the tender. I was wondering if you get a balance issue with the weight of the battery on one side of the tender?


Hi Jake!

We weighed the battery pack and a stack of the weight bars. Then we moved 4 weight bars (almost half the weight of the battery pack) to the other weight stack. That balanced the tender.

If you look at the first picture you can see the bolts on the top stack are filled, while bolts on the bottom stack have lots of thread showing.

#9
jonathan bliese said:
Just read the install article on the k27. Where is the fuse or breaker for the MANDATORY protection for charging and running circuits for this hardware? The article picture shows wiring direct from charge socket to what is likely a 25 cent Chinese made DPDT switch, and direct out to electronics. Safety? Jonathan/Electric /Steam Modelworks
Guilty as charged. There are no polyfuses in this installation.

The DPDT switch does have a center-off position however.

#10

I have a box full of failed toggle switches, from all kinds of installs, circuits etc… Off is NOT the same as “cannot short out” Take a toggle switch apart sometime. Inside are two small pieces of Phosphor bronze usually, arranged on a little fulcrum and pivoting like a see saw. There are sometimes small springs to assist contact, depending on quality. I can think of at least three ways this can fail and create a direct short.

Jonathan/www.rctrains.com

#11
jonathan bliese said:
I have a box full of failed toggle switches, from all kinds of installs, circuits etc.. Off is NOT the same as "cannot short out" Take a toggle switch apart sometime. Inside are two small pieces of Phosphor bronze usually, arranged on a little fulcrum and pivoting like a see saw. There are sometimes small springs to assist contact, depending on quality. I can think of at least three ways this can fail and create a direct short.

Jonathan/www.rctrains.com


What brand do you use??? I use Minitronic’s and not had a problem

Rodney

#12

Rodney, I did not say I installed those failed parts, or that I use them. I have been installing R/C in trains since the late 80’s. I have seen a lot of really screwed up installs,crazy , dumb things, and stuff just down right foolish. Repaired most of those, and fixed a lot of folks mistakes. I do not know anything about minitronics except that they cost more than they should, and Minitroncis does not make them, they source them. If you like them and have good results , good for you. Still no excuse for no fuse however, fuses or polyfuses are cheap and easy insurance. houses, garages and trains are not so low cost.

Jonathan/www.rctrains.com

#13

I"ll have to agree on having no protection. A fuse has saved me several times.

#14

The BIK series installation kits I make all have Poly fuse protection built in. I also use the same Salecom brand pcb mount DPDT switch for both the 3 amp and 6 amp kits. I have sold many 100’s now and only ever had one failure that I know of.
Jonathan sells the kits in the USA.

#15

Thanks for the reply Paul. After the re-reading the article I see where you mentioned moving the weight to counterbalance the battery.

I also was curious about the fuse. I used one in my K-27 install but was not sure if it was needed in my C-19 install. I will go ahead and install one. Afterall like Jonathan said it is not that expensive.

#16

A polyfuse fuse would be easy to install on the Interface board.

Remove the two wires used to trigger blow down. It’s an automatic sound function at start up anyway.

Remove the red wire from the battery screw terminal on the K27 PnP Socket, and fasten it in one of the empty screw terminals.

Fasten a red wire in the other empty screw terminal. The other end of the wire goes to the empty battery screw terminal on the K27 PnP circuit board.

Solder the polyfuse in the trace between the terminals. Open the trace between the soldered leads. I use a 1/8 drill bit in a pin vise for that purpose.

Now there is a fuse between the battery pack switch, the PnP circuit board, and all the other electronics.