Just wired up two transformers 2x25V to the power supply boards, when messuring the voltages V- PG- and V+ PG+ on both boards they started off at about 44v to 38v dc, and gradually went lower and lower to about 22v dc after one rectifier and about 33v dc on another, on the other board they did kind of the same, one was staying at about 30v dc, is this normal without a load connected?
These are the transformers I am using http://uk.farnell.com/multicomp/vtx-146-300-225/transformer-300va-2x-25v/dp/1675025
If you look at the data sheet on the link, I am not sure if I have wired them correctly, I have connected the Grey and Violoet wires together, and the Blue + Brown are connected to the mains?
These are the transformers I am using http://uk.farnell.com/multicomp/vtx-146-300-225/transformer-300va-2x-25v/dp/1675025
If you look at the data sheet on the link, I am not sure if I have wired them correctly, I have connected the Grey and Violoet wires together, and the Blue + Brown are connected to the mains?
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Ok I'm going to answer my own question, and I am an idiot! I didn't noticed but the fuse had blown.
So replaced the fuse with the correct type and I now messure 40v dc at each point on both boards, but this creeps upto 47v dc on each board, anyone know why this is please?
Surely with 2x25v it should give about 2x35v dc after the rectifier...25 x 1.414 = 35.35 VDC?
So replaced the fuse with the correct type and I now messure 40v dc at each point on both boards, but this creeps upto 47v dc on each board, anyone know why this is please?
Surely with 2x25v it should give about 2x35v dc after the rectifier...25 x 1.414 = 35.35 VDC?
Mine gave 36V + and - after the 1st smoothng cap. Deinfitely no gradual rising of the voltage. Are you sure you're measuring correctly?
Fran
I think so, meter set to DC and I placed the meter probes on PG- & V- and then PG+ & V+, they all sit at 40v for a moment, then rise to 47v
Yes - if you have the grey and violet joined together and the mains wired to the brown blue on the primary side, then you should get a pretty much dead constant AC voltage on the secondary. You mightn't get exactly 25V, but it'll be around that.
It pretty much must be your multimeter. I had one that gave me weird readings once when the battery was low.
Fran
It pretty much must be your multimeter. I had one that gave me weird readings once when the battery was low.
Fran
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