Timing the bell on a 2203B tender bell

I would imagine that it simulates the pulsing effect of a mars light.

Thank you.  I had no idea that was called the mars light.

I assume this is a follow-on to this earlier thread?

And the mechanism you are trying to electronically (vs. original bi-metallic strip) time/trigger is something like this?

The Mars circuit board you show has the ability to generate periodic/cyclic signals, but not the output drive capability to move this mechanism.  From what I can tell, the board does not seem to have the ability to adjust the timing if that's important (?)

If you post a photo of the tender innards with a ruler to give an idea of how much space you have available, it might be possible to cobble something together with low-cost electronic modules from eBay.  That is, I'm guessing you're not anxious to do a lot of component-level (diodes, resistors, capacitors, etc.) soldering and such...

Yes, tis is related to the earlier thread.  I found a flasher (bimetal) from an old water tower but the cycle is back ward.  In other words normally on, momentarily off.  I need my wife's camera to take and download the innards of the tender and will send it on shortly.

I'm learning too.  I found this page from Google Books searching for bimetallic water tower switch...

Are you suggesting you want to use the water tower switch for the timing function...and that the task at hand is now to convert from normally-closed/momentary-open to normally-open/momentary-closed?

The text suggests there are some mechanical adjustments that affect timing.  Though from a reliability viewpoint I'd think an electronic solution might be preferable and give a wider and more predictable range of operation if that's of value.

I just worked on the electronic version of the 455 Oil Derrick, your picture above shows the thermal switch version.

Basically, it is just a bridge rectifier with no filter cap, a 7808 8 volt positive regulator with a 470 uF cap on the output, and a 555 astable set up to give about a .25 second pulse every 3 seconds or so. 8 ohm operating coil is connected directly from the 555 output, pin 3, to the positive supply. Big current pulses through the 555 but the duty cycle is very low. Seems like this circuit would work in the bell application.

FWIW, mine had a failed 7808, the 555 was fine despite the "abuse." 

Right, I want normally open and momentarily closed and ability to vary the speeds

Sorry PCLPROF my response was directed  to  Stan2004

stan2004 posted:

I'm learning too.  I found this page from Google Books searching for bimetallic water tower switch...

Are you suggesting you want to use the water tower switch for the timing function...and that the task at hand is now to convert from normally-closed/momentary-open to normally-open/momentary-closed?

The text suggests there are some mechanical adjustments that affect timing.  Though from a reliability viewpoint I'd think an electronic solution might be preferable and give a wider and more predictable range of operation if that's of value.

Here is a picture you asked about.  Yes I want normally open, momentarily closed and the ability to vary the speed.

What is the part/board number for the 455 Oil Derrick replacement?  I'd think a quick measurement of the coil resistance on the tender bell clapper mechanism would determine if in the ballpark.  Old Fart, is this something you can do?

Good find!

Note: A gold star will be awarded if it turns out to solve the tender bell problem

PLCProf posted:

I just worked on the electronic version of the 455 Oil Derrick, your picture above shows the thermal switch version.

Basically, it is just a bridge rectifier with no filter cap, a 7808 8 volt positive regulator with a 470 uF cap on the output, and a 555 astable set up to give about a .25 second pulse every 3 seconds or so. 8 ohm operating coil is connected directly from the 555 output, pin 3, to the positive supply. Big current pulses through the 555 but the duty cycle is very low. Seems like this circuit would work in the bell application.

FWIW, mine had a failed 7808, the 555 was fine despite the "abuse." 

Thanks so much but, I have no electronic experience nor expertise.  So, your explanation is all greek to me,

Sorry Stan2004.  I have no clue.

No number on the board, a quick look on the Lionel web site came up empty, but I will sniff around a little more.

Here are some photos; footprint is about 1 x 3, maybe 1 inch in height.

Understood.  Well, I think we're at an impasse.  Without a known plug-and-play replacement module I think it difficult to guide you through a DIY modification if mucking around at the electronic component level is not in your comfort-zone.  That is, unless someone else comes forward who has worked on this problem with some technical notes, there are too many unknown unknowns so to speak.

I can imagine the 455 module board as a potential part of a solution, but I'm guessing it will require some additional components.  For example, based on PFCProf's photos, the board does not appear to allow rate adjustment. 

Of course, what's curious about the board is what appears to be a 94 date code.  So was Lionel repairing/swapping out the thermostatic switch with the electronic timer 20 years ago?  If the original thermostatic switch is extinct or close to it, I'd think others might have the same problem. 

So if you don't want to migrate to an electronic bell sound module, I wonder if there's a service tech here on OGR who would undertake a mercy mission!

I changed out the circuit board on a MPC oil derrick a few months ago.

The part # is a 2305-45 and bought it from Jeff at the Train Tender for $12.00 or so.

Don't know if it would work for you guys.

thanks, I'll look into that

stan2004 posted:

Understood.  Well, I think we're at an impasse.  Without a known plug-and-play replacement module I think it difficult to guide you through a DIY modification if mucking around at the electronic component level is not in your comfort-zone.  That is, unless someone else comes forward who has worked on this problem with some technical notes, there are too many unknown unknowns so to speak.

I can imagine the 455 module board as a potential part of a solution, but I'm guessing it will require some additional components.  For example, based on PFCProf's photos, the board does not appear to allow rate adjustment. 

Of course, what's curious about the board is what appears to be a 94 date code.  So was Lionel repairing/swapping out the thermostatic switch with the electronic timer 20 years ago?  If the original thermostatic switch is extinct or close to it, I'd think others might have the same problem. 

So if you don't want to migrate to an electronic bell sound module, I wonder if there's a service tech here on OGR who would undertake a mercy mission!

Well, if OLD FART can take very close up close-ups of both sides of his Mars light board, I will take a crack at figuring out what he has. My guess is that his board is reasonably close to what he needs.

What say, OF? I might need the tiny numbers printed on the components. You will probably need your best bifocals for that assignment!

Well, I just burned the circuit board up.  So I am continuing my quest.