AE 96-E Missing Inline 22A433-2 Diode

[Connu]

I'm just finishing up a 96-E-10 and have another on the bench.  I used Voip.ms like Stan S recommended to test the first one.  Voip.ms supports reverse polarity on caller pickup and the transmitter is disconnected when a placed call is answered.  The transmitter is reconnected when I drop a dime or quarter.  It took a TON of fiddling and adjustment to get the old coin relay pile to make the proper connections, but it was worth the time! The phone works automatically and unattended like it was supposed to.

I do have a question though.  My latest 96-E was missing all the coin relay "guts" including the inline 22A433-2 diode. I've got a relay, coin pile, hardware, and vintage wiring to get it back together, but I can't find the diode that's in line with the L2 terminal.  Why did people tear the good stuff out rather than just disconnecting it!  I'm not using a ringer.  Do I even need the diode? Was the diode just a protective measure?  Any insight would be appreciated.       

[Stan S]

Connu- Yes to the rectifier. I doubt that you will find a selenium rectifier like the original but you never know. You can use a modern silicon diode like a 1N400/anything. 4001-4007. The diode is used as a series element that detects the polarity of the tip and ring. The cathode (lined end) goes toward L2.

[Connu]

Thanks Stan.  Your knowledge runs deep.  I'm not much of an electrical engineer!  I knew it was a type of diode.  It converts AC to DC, correct?  My question is this.  Where would the AC voltage come from?  Isn't telephone service DC?

[Stan S]

Diodes can do many things. If you apply DC depending on the polarity they will pass the voltage or block it. That's what's happening in the payphone. When L2 is negative the voltage is passed to the relay coil. When L2 goes positive the diode doesn't pass the voltage so the relay doesn't operate.

[Connu]

Makes sense now.  I overlooked that they only only allow current to flow in one direction. You stated this in your first post.  Thanks for the help and the info regarding a substitute.

[Stan S]

Connu A little expensive but worth it if you are a stickler for authenticity.  https://www.ebay.com/itm/205977061468

[Connu]

Hi Stan.  I missed your last post.  I try to be a stickler, but the shipping is four times the cost!  Do you know what the specs are on the diode?  I found another that appears to be the same physical size, but I'm not sure if it meets spec.

[Stan S]

Connu I'm sure whatever you found will be fine. Very low voltage and very little current involved.

[Connu]

I looked up the specs on the 1N400 you referred me too in your earlier post.  It has a max voltage of 50V.  The c/o signal was 110V.  Are you suggesting the 1N400 to work with your controller and others?

[Connu]

Definitely very low current.  BTW, I noticed your controller is no longer on eBay.  Is that it for them?  I was going to ask you to work with me outside of eBay and noticed it was gone this morning.

[SUnset2]

I looked up the specs on the 1N400 you referred me too in your earlier post.  It has a max voltage of 50V.  The c/o signal was 110V.  Are you suggesting the 1N400 to work with your controller and others?

The poster was referring to the 1N400x series.  The most common is the 1N4004, which is rated for 400V.  They are very cheap and common.  I think I have a bin of them somewhere.  Let me know if you would like me to stick a couple in an envelope and mail them to you (mine might have short leads).  Or you can order a big pack of them online.  If you work on tube equipment, you might want to get the 1n4007 instead, they can handle 1000V.  Be aware that these diodes do not work well at high frequencies, but should be fine below 1kHz. 

[Stan S]

Connu all my controllers were designed for prepay phones. The two payphones you are playing with are postpay. Any 4000 series diode you will buy today will work fine in that circuit. The biggest problem with a selenium rectifier will be finding one that's small enough to fit physically in that space. All the controllers from the last build sold. I doubt I will build any more of them.

[Connu]

The poster was referring to the 1N400x series.  The most common is the 1N4004, which is rated for 400V.  They are very cheap and common.  I think I have a bin of them somewhere.  Let me know if you would like me to stick a couple in an envelope and mail them to you (mine might have short leads).  Or you can order a big pack of them online.  If you work on tube equipment, you might want to get the 1n4007 instead, they can handle 1000V.  Be aware that these diodes do not work well at high frequencies, but should be fine below 1kHz. 

I'm not sure why I'm no longer getting notifications, so I missed your reply and Stan's.  I should have looked quicker since Stan ALWAYS replies quickly!  Thanks for your reply and offer.  I'm not an electrical engineer by any stretch, but I got an A+ in my high school electronics class.    Stan had mentioned that any of them from the 4001 to the 4007 would work.  That's why I was asking about the voltage and specifically the voltage his controller uses to trigger the coin return relay in prepay phones.  It would be great if you could send a few.  I'll send my address. Cheers!

[Connu]

Connu all my controllers were designed for prepay phones. The two payphones you are playing with are postpay. Any 4000 series diode you will buy today will work fine in that circuit. The biggest problem with a selenium rectifier will be finding one that's small enough to fit physically in that space. All the controllers from the last build sold. I doubt I will build any more of them.

Hi Stan.  I didn't realize you had responded. I understand that I was specifically asking about a semi-postpay.  I also restore and refurbish prepay phones to. I have a 62 with a built-in controller.  I just finished up a really nice 62-55 that I found with a "salad fork" hook and bent magnet coin relay.  Now adays it's like winning the lottery.  I'm finishing up a 92-W-55 and trying to figure out how it would have had a WE dial mounted.  I think I'll start another thread on that one.  Finally, I'm also trying to piece together a 150GJ but I'm still a few parts away on that one.  The 62-55 is complete now and that's why I asked about your controller.  I can't believe it sold the day I went to ask about buying it.  Keep me in mind if you do make some more or know someone selling one.