Similarity or difference between AT&T 6300 power supplies

[alejack12001]

I am trying to find out the similarity or difference between AT&T 6300 power supplies. An recently acquired AT&T 6300 power supply has a label ALI LA16/B-ALITEC along with a serial number shown. Earlier power supply acquired 3 years ago has ALI LA 16-MACOM and serial number on it. Another user of the forum posted an inquiry regarding the "B" number asking if anyone had a schematic of the "B" and he didn't receive an answer.

What is the difference between the two listed power supplies? Is the "B" made for 6300 plus and the 16 or 16A made for just a 6300?

 

[1ST1]

Alitec and Macom are the manufacturers. Alitec was the more popular for the M24, but both were used in M24, M24SP, M21. M240 has a different powersupply. Alitec made a lot of differernt powersupplies for Olivetti, for many models.

 

[alejack12001]

Thank you for your information regarding the power supplies for both AT&T 6300 and Olivetti M24. The Alitec is the 16B that I bought recently. While the AT&T service manual make mention of the 16B there is no schematic diagram available that I am aware of. Another member posted the same question to me some weeks ago. The 16B that I received is not functioning at +/-12Volts and of course the 15 volts. My measurements no load are registering 13 mvollts plus side and -7.7 volts negative side for the +/- 12 volt connection. the 15 volt or 14.2 as the service manual specifies is registering 4.7 volts. I have traced it down to F2 which appears to be a thermistor or possibly a SCR.There are no markings showing a number of manufacturer for the component. PS is useless for me.

The Macom 16 I have as well and is shown in another post; I don't have any output at all right now. In this I believe the coil of the secondary of the power transformer is open. I have taken an interest in the Xerox development by Valerio. If 1st1 happens to have a schematic of the Alitec used with the M24 could you please share that with the forum. I think it would generate quite a lot of interest.

 

[1ST1]

I have no other documentations than Trixter in his 6300 shrine.

Please be carefull with these powersupplies (also that one for M240, M28, M280, M290, M300, ...), don't try to power on them without a load. They may survice that, or not. When I was working with these poweresupplies 30 years ago I was instructed to not run them without load as this would damage them. Unfortunatelly I don't remember much details, long time ago. Thermistor, thyristor, things like that inside, different from modern psu. Maybe I will find some time to have a look into my machines (several M24, M24SP, M240 and one M21 of different production years) to see which powesupplies are used there. Be carefull when trying to fix / them outside of their chassis, you have several points of high voltage, don't touch the wrong places... I personally don't like much servicing these psu as they consist of two boards, connected through a toooo short cable whcih has high voltage, not good to reliable testing them dismanteled on the desk. At Olivetti Frankfurt we had a special safety electronics desk to test /repair these psu, with electrical load to connect, long connection cables for the two boards, FI-switch, etc.