Adding Stay Alive to Diesel Locos

It turns out the KAM decoder is just too large for the little loco I’m building. It fits but protrudes a couple of mm beyond the side tanks, meaning the viewer can see it. I’ve removed it from the Minitrains chassis and soldered it to a Kato 103 chassis from one of my O9 diesel locos.

I removed the lead from the inside of the body and there’s just enough room for the KAM decoder. Now both of these locos have a stay alive decoder fitted.

What’s the point of a stay alive? When there’s a momentary loss of power due to a poor connection, or dirt on the track the loco will keep running on the most recent settings until it’s told to do something different. This leads to very smooth operation.

This video shows the stay alive effect. I started the loco running then switched the controller off at the mains so there was no electricity going to the track. Watch how the loco just carries on!

No power to the track and the locos still moving, it’s crazy really, but why bother? Well, I’ve been wondering how to use the Peco 009 228mm (9 inch) radius insulfrog points with DCC. This test shows that with a stay alive fitted the insulfrog wont be a barrier to smooth running…


    • Hi Bill,
      Good question, I forgot to explain that bit. This DCC chip has a built in capacitor that stores electrical energy. When the power is cut off (for whatever reason, dirty track etc) the power stored in the capacitor is used to run the loco. The DCC chip continues doing the last command it received until it receives another command from the controller. When power is restored and the operator tells the loco to do something else such as slow or stop. In this case as the controller was off I couldn’t tell the loco to slow / stop so it just carried on until the power in the capacitor was exhausted… Most power outages are very short lived (hopefully!) so the operator regains control very quickly, probably without even noticing the capacitors had cut in. All the best Stephen


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.