Next 18 decoders and stay alive

[Roger Sunderland]

Hello there

i have a Lais DCC breakout board for a next18 decoder. Am I right in thinking that a 2 wire stay alive should be connected to the pads on the board marked + positive and ground?

[Nigelcliffe]

Yes,   Your stay-alive device needs a charge-limiting resistor (at a minimum) to prevent decoder overload.  Many packaged commercial devices would include this.  

[Vecchio]

If it is a smaller capacitor you can even do it without the charge limiting resistor (less than 1000 uF). The tricky bit is to solder a wire to ground. (which is actually the pin right in the middle, and available on both sides) The positive one will be available also elsewhere in case your model has working lights. This makes it easier for soldering. 

I use normally an enamelled wire and a special pencil type tip on the soldering iron.  And of course magnifying lenses.

 

Just saw you have a breakout board. so this makes it easier. But why a next 18 decoder if you have space for a breakout board?  I normally use them only if space is a problem. Like in this little . Stay alive (500 uF tantalum) and sound added. 

 

20200531_155225 

 

20200531_163923 

Edited June 11, 2022 by Vecchio

[Roger Sunderland]

Thanks both of you. Two reasons for using the breakout board. One , with my shaky hand there is no way I could solder to the pins and two, the combination fits the space I have available rather well.