I have a couple of centercabs (including my new 628) with bad E-units.  I'm not inclined to rebuild them at the moment, so: 

Rather than shell out $40 for new ones or $20-35 for a Lionel disc switch, is there a way to use a $3 toggle switch from Radio Shack as a reverse switch?  If so, how?

Thanks! 

Mitch

It's crackers to give a rozzer the dropsy in snide!

 

Remember, SCROUNGE!

Original Post
Dennis LaGrua posted:

You could probably do reversing with a DPDT switch but why chop up good equipment?  If you don't wish to repair;  wire direct to the track for forward only operation.

Nah, I wanna be able to reverse it.  My question is:  How does one wire the DPDT switch? 

Mitch

It's crackers to give a rozzer the dropsy in snide!

 

Remember, SCROUNGE!

Let's say you are using the red & black wires to your brushes for hard wiring the loco in forward only(armature & field wired in series to track power).

Now, disconnect those two wires and wire them to the back of a DPDT switch like this:

DPDT

Now, connect blue & green wires to brushes from switch. Done.

Rob

Attachments

Photos (1)

On a Lionel post war motor, the power goes through the armature coils and then through the field coils.  They are in series.  To reverse the motors direction, reverse the wires to the brushes, without reversing the power to the field.  In most postwar motors, one field wire is grounded to the motor frame, so reversing the brushes or the way to go.  There are a few post war motors with double wound fields.  They will not have three position e units and would be connected differently to reverse them.  In Rob's drawing, the red wire would be coming from the current collector (center rail) and the black wire would go off to the field connection. I do not specifically recall the 628, bur frequently Lionel put a third lug on the brush plate for the field lead to connect to.  

Shades of the 30's.  Before the e-unit came out around 1940+/-, Lionel locos had a manual switch for reversing.  When the e-unit first came out, Lionel added an E suffix to loco numbers to indicate its presence.

QSI used to make an device called an ACRU, silent electronic reverse unit that always started in neutral-before-foward on powerup.  Excellent device.

Okay, I think I have this sussed: 

Reverse Switch

Using Lionel's color schema, here's how I think things should be wired.  The black wire from the pickup goes to one center contact of the DPDT switch, the yellow wire from the coil goes to the other, and the blue and green wires go to outside contacts with a crossover.   Thus, when the blue wire is energized, the green brush energizes the coil, and vice versa.

Have I got it?   

Mitch

It's crackers to give a rozzer the dropsy in snide!

 

Remember, SCROUNGE!

Attachments

Photos (1)

Use this diagram,(disregard your bottom image - both brushes are "energized" when current is flowing through the circuit):

DPDT

If it's a single wound field, you need a DPDT. With a double wound field, you can use both windings and a SPDT, or one of the windings and a DPDT as with the single wound field.

Rob

Attachments

Photos (1)

I favor manual reversing switches to replace troublesome e-units. If you use a center-off switch, the off position allows you to park a loco anywhere on your layout. Manual reversing switches are also handier for MU'ing locomotives. I position the switch handles to stick out the existing slot for the e-unit lever.

100_3033100_4143

For 2-position e-units used with Lionel double-wound fields, a SPDT switch does the job. One field winding is used for forward, the other for reverse.

Attachments

Photos (2)

If you choose to do this thing,  use a good switch and not RS.  I would not do this.   If you crap it up like you are talking about your finished product will still be junk.

 

 

TCA-79-13758

T.T.O.S.-3057

LCCA-28444

LOTS-RM-4833

MTH Railroaders Club-17209

MTH DCS and Wi-Fi  Beta Tester

MTH Factory  Certified Technician-6 schools.   Repair Technician #990284

LIONEL Factory Trained Certified  Repair Technician #10140

Member Mid America 3 Railers and NJ HiRailers

 

 

 

Add Reply

Post
OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
330-757-3020

www.ogaugerr.com
×
×
×
×
×