Lionel Electronic E Unit PCB

I never ran across one of the "slow" ones, I don't know what it would take to light a fire under it.

Thanks, John.  Silly me, I thought that the slow might refer to a delay when switching between forward-neutral-reverse-neutral to prevent kids from changing directions too fast since there was a reference to Thomas the Tank Engine.

It may be as silly as a different component, but without analyzing what you have, that's hard to say.  However, I can provide you with some interesting material if you are looking to see what's different.  How about a complete schematic and circuit description of the reverse board?  A member here did a reverse engineering exercise using that board, and created a very detailed document, see attached.

Lionel E-Unit 00-0103-00 Theory Of Operation.pdf

@gunrunnerjohn posted:

It may be as silly as a different component, but without analyzing what you have, that's hard to say.  However, I can provide you with some interesting material if you are looking to see what's different.  How about a complete schematic and circuit description of the reverse board?  A member here did a reverse engineering exercise using that board, and created a very detailed document, see attached.

Lionel E-Unit 00-0103-00 Theory Of Operation.pdf

Thank you John for posting this.

While specific for the Lionel Board, is this pretty similar to the QSI DCRU boards used in the Weaver Locos and K-Line ERU's?

Actually, the Lionel E-Unit board is nothing like the QSI DCRU boards.  The DCRU boards are MUCH more robust in that they use relays to handle the motor current, the Lionel board uses the TIPxxx transistors without any heatsinks.  The Lionel board really isn't good for more than about an amp, the QSI reverse boards will handle many times that.

Thank you VERY MUCH John for the reply.  Still trying to figure out how all this 3R electronics works!

@MainLine Steam posted:

Still trying to figure out how all this 3R electronics works!

Much of the time, pretty well.

Can we still get the DCRU?

@gunrunnerjohn posted:

Much of the time, pretty well.

  Still trying to figure out which I admire more, your knowledge of electronics or your sense of humor?  Thanks again!

@ogaugenut posted:

Can we still get the DCRU?

Many folks still have DCRU boards in boxes, I believe I have several left over from upgrades myself.