E unit silencing solution

An ingenious adaptation of Magic-Electrol, however, I have not experienced this at all in ~ 30 years of running Lionel engines like this.

If you want to degauss a "magnetized" E-unit solenoid, for whatever reason, run it on AC.

I'll bite. let's see the circuit!

As for copying a cad drawing try [PrntScr] and paste it in a picture program (paint will work), save as .jpg or use the 'snipping tool'

See if this drawing makes sense to you rkenney.  

Great Job....

Clever solution. Is your relay actually a 16 pin DIP? If so, what is the part number and current rating?

Pete

Did you try using the relay to pulse the normal AC through the E-unit's coil?  Seems like a 1 second pulse would not make enough noise to bother most people.

I did use the ac initially but decided that if I don't like to hear the buzz all the time, I don't like to hear it for 1 second!!!   The DC was available anyway and it was pretty easy to isolate the E Unit coil from chassis ground.  I now have a really cool working model of a way too involved set of circuit boards fit inside my Boston and Maine GP-9 that does the E unit trick and also has diesel engine rumble sounds that  vary with engine speed, a nifty diesel horn that is triggered by the Lionel horn/whistle relay, a mini audio amplifier and even a circuit that maintains the dc power to all the required electronics with a 9 volt battery.  That battery is only required to give current when the track voltage is turned off.  This keeps the diesel sound running or the horn honking when the diesel E unit is activated.  10 seconds after no track voltage is sensed, the battery is disconnected from the circuit and remains dormant until the track voltage returns.

I am working on a final set of schematics and maybe even a board layout for this concoction!!  I really tried to get it all inside the GP-9 even with a small speaker but it was just too much and the tiny speaker sounded fake.  I now have a dummy Boston and Maine GP-9 that carries a pair of oval speakers.  Two grayish wires leave the powered engine and drape over the shared couplers to feed sound to the speakers inside the dummy. Kinda looks like air line if you squint.  

Hey Pete, the relay is an Omron G5V-2 which is a 5 volt relay in a dual in line size package.  It makes it easy for IC sockets because it snaps into a 16 pin DIP socket.  This relay is only meant to get 120% of 5 volts for much time.  The 555 timer only generates about 6 volts on pin#3 when it times out.

That has been done for many years.  Not something new.  Back in the mechanical E unit days, many operators used the DC fix.

And within the past 25+ years, removing or bypassing the E unit with a DCRU instead.

Marty, I think what makes this different is pulsing the E Unit. Most of the time there is no current going through the coil. I agree running the coil on DC has been around for a quite a while.

Pete

If you can open a DWG file, I have attached the final(and quite complicated) circuit I have created.  I uses a modified existing diesel sound circuit in conjunction with an E Unit timer circuit and even a 9 volt rechargeable battery supplementary circuit for when the track voltage is interrupted.  This keeps the diesel rumble and the horn features working when the track voltage is missing during E Unit transitions.  There is a 555 timer circuit that disconnects this battery after 10 seconds on no track voltage.

The trick is making it compact enough to fit inside the diesel engine body!!

Dumb question Kenai, why not export this to a graphic format that maybe more folks would likely have access to?

instead of talking all about the circuit lets see a schematic diagram of the exact circuit with parts numbers so we can try your circuit!

Alan

It's a clever idea but it seems like a lot of complication for an anachronistic old E-unit. If I have E-unit problems I find it's more expedient to simply put a manual reversing switch on the loco, which also simplifies double-heading arrangements. I don't want sequential reversing for most of my O-gauge train operations; I usually lock out the E-unit.

How about the DWG in a PDF file?  You will need to enlarge it at lease 200% to begin seeing the numbers on components.

I think Dale M hit upon the simpler solution. Use the 555 to trigger the relay but have the relay switch AC not DC to the E unit coil. You would need clean DC for the 555 but a 100ma regulator and few caps would do it along with the required timing components for the 555.

Pete

I like my buzzing e-units. 

I find this to be a easy solution to quieting the mech. E-unit,

Bill