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Discussion Boards => General Discussion => Topic started by: Trainmaker on March 03, 2019, 11:06:51 PM

Title: Installing a Keep Alive in Bachmann S4 With sound
Post by: Trainmaker on March 03, 2019, 11:06:51 PM
Does Anyone know how to install a Keep Alive in a Bachmann S4 with sound?? I'd Appreciate any help.
Title: Re: Installing a Keep Alive in Bachmann S4 With sound
Post by: rich1998 on March 04, 2019, 11:28:53 AM
A keep alive has two wires. Positive and negative.
Look at the decoder board for the positive and negative points. Best point for many is at the output of the full wave bridge rectifier which consist of four diodes next to each other. Get out your Optivisor and ohm meter and trace out the circuit. The below link will show examples.
Some decoders have more diodes next to each other.
I have not looked at the decoder layout.

http://www.members.optusnet.com.au/mainnorth/alive.htm

I am sure someone will chime in since they know the decoder. Get i right the first time. You do not want reverse polarity on a keep alive. You don't.
Be advised, if running the loco on DC, you will have no control, even if you turn off the power pack but that is rare.

Rich
Title: Re: Installing a Keep Alive in Bachmann S4 With sound
Post by: Trainman203 on March 04, 2019, 11:29:02 AM
I don't know how, but if I'd  bought one, I would read the instructions several times and get done specific questions first.
Title: Re: Installing a Keep Alive in Bachmann S4 With sound
Post by: Trainmaker on March 05, 2019, 09:40:18 PM
Thank You rich1998, The net address was 100% helpful! Thank You Too Trainman203, I'll make My question clearer next time.
Title: Re: Installing a Keep Alive in Bachmann S4 With sound
Post by: rich1998 on March 06, 2019, 05:49:00 PM
In case you have not soldered before, a fine point 40 watt soldering pencil for PC board work. I have no idea of your soldering experience. Just remember, electrolytic caps do not like reverse polarity.

Rich