E-unit with rectifier wiring diagram needed

https://ogrforum.com/...with-a-lionel-e-unit

Thanks for the link.

I installed a 4 AMP full wave bridge rectifier in a 2343 Santa Fe F3, following the diagram.  Very easy.

Wow, there is no buzzing at all!  Its sounds as quiet as an electronic E-unit.  However, it still has the pleasant clicking when the pawl goes up and down, and, of course the ozone smell.  To me, its the best of old and new.

I now will install an Electric Railroad Railsouds board, and it will not be drowned out by the buzzing E-unit.

However wonder if over time the plunger will become magnetized and just maybe start sticking to something metallic within the e unit.  I think I recall reading that some accessories solenoids or other magnetic (the ubiquitous up/down crossing gates comes to mind) might exhibit stickiness after operating on DC, but could be wrong.

Also be aware that electrically, the accessory solenoids are wound for AC operation with the windings acting as impedance (i.e. AC resistance) choke coils with a relative low DC wire resistance.  When DC is applied there is no impedance to limit current, just the wire resistance, and depending on the voltage and coil DC resistance, the winding MIGHT become overheated distorting the coil form jamming the plunger or wire just burns open.

Anyone run into this problem?

@rrman posted:

However wonder if over time the plunger will become magnetized and just maybe start sticking to something metallic within the e unit. ..

There must be some easy way to negate that if it happens.

I just connect it to AC and cycle it a few times, magnetism gone.

Whenever I ran my universal motor/E-unit locos on track DC power, they always ran smoothly and quietly. It got to the point that I hardly ever ran them on track AC.  Never incurred any E-unit issues because of the DC power.

Here is a buzzing E-unit with AC coil power on my Lionel 2337 Wabash GP9.

Here is a quiet E-unit with DC coil power on my Lionel 2343 F3.  There is no buzzing at all!  I really was surprised how using a rectifier the E-unit coil completely eliminates the buzzing.  Now, I have to order more 4 AMP full wave bridge rectifiers for the rest of my roster.

@rrman posted:

Also be aware that electrically, the accessory solenoids are wound for AC operation with the windings acting as impedance (i.e. AC resistance) choke coils with a relative low DC wire resistance.  When DC is applied there is no impedance to limit current, just the wire resistance, and depending on the voltage and coil DC resistance, the winding MIGHT become overheated distorting the coil form jamming the plunger or wire just burns open.

Anyone run into this problem?

Yep - the first sign of trouble was detected by my nose - the smell of a hot coil is quite distinct. Of course I had added a big honkin' cap to smooth out the DC as much as possible, thus making the operation totally silent. It worked great! The 151 semaphores and my O27 switches were silent, but if you delayed a train anywhere for even a short time, those coils got hot! The big caps raised the effective voltage of the pulsing DC to very near the peak-to-peak, or about 40%, as I recall. I quickly learned to just enjoy the buzz

George

@rrman posted:

However wonder if over time the plunger will become magnetized and just maybe start sticking to something metallic within the e unit. ..

There must be some easy way to negate that if it happens.

@gunrunnerjohn posted:

I just connect it to AC and cycle it a few times, magnetism gone.

I knew it! Easy fix.