WESTERN ELECTRIC COPPER OXIDE RECTIFIER BOX J86205H L1

[wfs1933]

Does anyone know what this is?  its a standard metal WE bell box with label on it stating "copper oxide rectifier J86205H L1" inside are componets (no ringer) 105-125 volts, 60 cycles, 12 watts.

[Bartonpipes]

It looks like it is exactly what it says. Simply put a rectifier takes alternating current and turns it into pulsating direct current. The capacitor at the extreme left would take that pulsating DC and flatten out the wave form so it was just straight DC.

My guess as someone relatively new to this is maybe it was a power supply for a western electric switchboard or maybe a key system unit?

I'm sure someone else can add more to this.

[poplar1]

This J86205H List 1 rectifier is "used to furnish filtered DC for an intercommunicating line and AC for operating bells and buzzers."

Ref: http://www.telephonecollectors.info/index.php/document-repository/doc_view/11914-c70-025-i1-apr59-stations-systems-power-supply-identification-ocr-op-r (Contributed to TCI library by Steve Cichorsky and Steve Hilsz)

[unbeldi]

Does anyone know what this is?  its a standard metal WE bell box with label on it stating "copper oxide rectifier J86205H L1" inside are componets (no ringer) 105-125 volts, 60 cycles, 12 watts.

Where did you find it?
Quite nice item.
Notice the 101A induction coils to decouple the stations on the intercom circuit.
Can you trace the circuit and create a drawing?   PS: I see there is a diagram in the box, can you take a snapshot ?

[unbeldi]

I expect the diagram of this box to look similar to the following circuit.

I know I can trace the wires in the picture to some degree and improve the diagram...
The placement of the fuse in my diagram is logical, but it seems perhaps not as in the set.  It may just fuse the secondary winding, the apparatus circuit as is done with all key systems supplies, and not the primary.

It is also possible that the arrangement of the induction coils is different. Perhaps it provides more of complete talk path between two stations. The diagram simply provides talking current for two sets.

I haven't found a BSP yet that still shows the circuit.

[unbeldi]

The other circuit I have in mind for this provides the two induction coils in a back-to-back configuration, like a repeater station with the DC supply common to both coils on one side.  This would make a complete communication path.

But somehow, I have the feeling the induction coils are simply used as retardation coils, as  was for example the No. 46 coil in the 684BD subscriber set, which this diagram is essentially based on.

Here, the extremely large capacitor of 500 µF acts as the common battery and is kept charged by the rectifier.  The large capacitance ensures there is no line power frequency ripple present on the DC supply.

[wfs1933]

This was on Ebay for about $10, now i wish i'd bid on it!
it sold for under $25 i think.

[unbeldi]

This was on Ebay for about $10, now i wish i'd bid on it!
it sold for under $25 i think.

Certainly an odd item...

I was looking on eBay when you posted but couldn't find it.  Do you have a link or auction number?
Were there additional pictures?  I'd like to store them for my records.

These items often go for very little, as not many people are looking for odd items like this. This one seems to have been in nice shape, although I would have been very cautious connecting it to power. Certainly I would have used the variable isolation transformer to crank up the voltage slowly.

[DavePEI]

This one seems to have been in nice shape, although I would have been very cautious connecting it to power. Certainly I would have used the variable isolation transformer to crank up the voltage slowly.

Methinks it quite likely could be a Pyrotechnic unit if one didn't! Copper oxide and early selenium rectifiers tend to have a pyrotechnic quality if not powered up for the first time in years very carefully!

One of my British Strowger switches had a copper oxide rectifier which created lots os smoke and a huge smell! Fortunately, the copper oxide rect. can be replaced with modern rectifiers if it goes!

Dave

[unbeldi]

This one seems to have been in nice shape, although I would have been very cautious connecting it to power. Certainly I would have used the variable isolation transformer to crank up the voltage slowly.

Methinks it quite likely could be a Pyrotechnic unit if one didn't! Copper oxide and early selenium rectifiers tend to have a pyrotechnic quality if not powered up for the first time in years very carefully!

Probably not the rectifier, it's only sitting on 3 V  and has no load connected.  Perhaps the secondary coil has enough impedance to handle a short circuit easily which would only be a a hundred mA may be a little more. These were to power transmitter units, not television sets.

The joy would be to keep the set original and not have to replace anything, just keep it as a display, and if defective this whole four-pound box can be replaced with a $5 wall wart.

I was more concerned about dielectric breakdown in that transformer can, since it appears to be metal and is connected to the frame.

[Dan/Panther]

In The radio Collecting field, Rectifiers are routinely and almost ALWAYS replaced as unreliable. Personally I've not had that experience, but maybe it turned out to be a bad idea ?
D/P

[unbeldi]

In The radio Collecting field, Rectifiers are routinely and almost ALWAYS replaced as unreliable. Personally I've not had that experience, but maybe it turned out to be a bad idea ?
D/P

Well, I think parts should be tested carefully.  But in any event, these old copper oxide rectifiers (or the selenium types) were not nearly as efficient as their replacements later.
So, if one actually wants to use the equipment, by all means exchange them.

Not all should be simply replaced though. Power supplies, including the transformers, were often designed around the specific properties of copper oxide devices, so that silicon diodes are not entirely satisfactory always. It would probably be best to replace the entire power supply in those cases. (or many cases?)

This one contains a No. 23A, which Western Electric actually listed as a varistor.  Or a varistor stack, not sure.  Last night I search for replacement parts, and found a BSP that specifies the KS-15657 for the same application. This part they called a rectifier.

I believe this difference in nomenclature is actually the reason why copper oxide devices should not be indiscriminately replaced with silicon diodes, the current-voltage response curves are different, and they are somewhat separate classes of devices.

[Bartonpipes]

Don't forget, older type rectifiers (in general) have a resistance to them that must be tested and a new wirewound resistor of the appropriate value should be placed in series ahead of the new silicon rectifier/diode.

In radios you usually only find half wave selenium rectifiers which of course are a different type than the copper oxide rectifiers. 

There is another sort of lazy approach I have come upon in a few old radios, where someone has put a silicon diode in series before the selenium rectifier.

[unbeldi]

Don't forget, older type rectifiers (in general) have a resistance to them that must be tested and a new wirewound resistor of the appropriate value should be placed in series ahead of the new silicon rectifier/diode.

In radios you usually only find half wave selenium rectifiers which of course are a different type than the copper oxide rectifiers. 

There is another sort of lazy approach I have come upon in a few old radios, where someone has put a silicon diode in series before the selenium rectifier.

Only extra heat is gained by putting them in series and reducing the rectifier efficiency.

However, Selenium devices had better efficiency than copper oxide did, but it deteriorated during use of long periods because the forward voltage increased over time (increased resistance) especially when the devices were not used for a long time. I think this may be the reason for them being removed as standard procedure.

The KS-15657 I showed earlier probably is a selenium replacement for the 23A.

[wfs1933]

Heres the Ebay link, was listed as a subset box

http://www.ebay.com/itm/Antique-Western-Electric-Metal-Telephone-Ringer-Box-/261750678497?