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Post by rudy18d on Jul 19, 2022 6:19:54 GMT
Working on a Continental 2 junction box that was sent to me after blowing fuses and transformer getting very hot.
Upon receiving I brought it up slowly on a variac and transformer never got hot but did notice that the DC voltage that was supposed to 50V was reading 40V coming straight off the secondary and then 29V once it went through the diodes.
I am guessing that the under voltage is probably what was causing the overheating because was told it only over heated when gripper was picking up records.
Anyway, anyone know of a replacement transformer for this junction box? 115V Primaries and 50V Secondary with CT.
Thank you,
Rudy
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Post by jukenorman on Jul 19, 2022 7:12:44 GMT
Hi Rudy,
Where are you getting the information that the secondary voltage should be 50VAC - that seems way high to me? Having said that, 29VDC is definitely too low with no load! Have you checked both diodes?
Norman.
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Post by rudy18d on Jul 19, 2022 14:56:27 GMT
Yes, I replaced each diode. Same voltages. I got the 50v voltage from here: www.west.net/~jay/jukebox/amijunction.htmlHaving trouble reducing a .jpg to a small enough size to post here in this forum, sorry. Thanks Norman! Rudy |
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Post by rudy18d on Jul 19, 2022 15:11:48 GMT
Upon further review after a night's sleep, I now see the 50v as the rating for the 1000uf electrolytic cap. So...I guess my question now will be what should the voltage be downstream from the diode for optimal performance? The schematic shows no transformer or diode voltage.
Thank you, sorry for the confusion.
Rudy
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Post by jukenorman on Jul 19, 2022 16:55:48 GMT
Hi Rudy,
Yes I was aware of that website. I waould have thought approaching 40V would be around the no load output of the transformer and that should produce a no load DC voltage of well over 50V. I don't mean to insult you - but you have connected the diodes the right way round when you replaced them? Another thought, when you're measuring the DC voltage, you need to do it relative to the transformer centre tap - although I'm strugging to envisage where you might measure 29V DC if everything was in order!
Norman.
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Post by rudy18d on Jul 19, 2022 18:18:08 GMT
No worries. Yes sir, they are in the correct way. I concur that the no load of 50V DC should be expected...I am struggling here because this is really a pretty simple setup in the junction box. Shouldn't be this difficult to figure out. I will dive back into it again this evening.
Thanks again Norman!
Cheers,
Eric
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