Banned
Joined 2002
Boy, take a little break for personal reasons and the doom and gloomers come out of the woodwork!
Here is a link to view the parts kits assembled on a pair of Kari's boards as well as some notes on construction. I will start preparing kits for shipping this coming week. I will get a few parcels wieghed at the Post Office and start sending out shipping invoices the week after next.
Regards
Anthony
http://www.briangt.com/gallery/album12
Here is a link to view the parts kits assembled on a pair of Kari's boards as well as some notes on construction. I will start preparing kits for shipping this coming week. I will get a few parcels wieghed at the Post Office and start sending out shipping invoices the week after next.
Regards
Anthony
http://www.briangt.com/gallery/album12
Lgreen,
Mouser part #: 532-531202B25
I got some left for sale, refer to link below:
http://www.diyaudio.com/forums/showthread.php?threadid=58470&highlight=
Mouser part #: 532-531202B25
I got some left for sale, refer to link below:
http://www.diyaudio.com/forums/showthread.php?threadid=58470&highlight=
I would test it on the pwr board alone. Add a 15kohm between +60 and gnd, measue what you get out.
You should get around 64V out. 67*1.4 ~ 94V, so you have around 14V "extra" which the fet has to dissipate in heat.
Keep an eye on the heatsink so it doesn't run too hot.
As for the - part you can't use the voltage you have, the fet would not cope with it.
/Kari
You should get around 64V out. 67*1.4 ~ 94V, so you have around 14V "extra" which the fet has to dissipate in heat.
Keep an eye on the heatsink so it doesn't run too hot.
As for the - part you can't use the voltage you have, the fet would not cope with it.
/Kari
I use a 2 x 30V transformer so ihave ~ 65VAC in on idle. After retification i have 65*1.4 ~ 90V. The output voltage is set by the zeners ( 7 * 9.1V ~ 64 - loss in the mosfet).
Yes i only get 64V regulated out.
Just connect the trafo to the pwr board ONLY and load the output with 15kohm and measure. It really isn't that critical if you get 60V or 65V out.
/Kari
Yes i only get 64V regulated out.
Just connect the trafo to the pwr board ONLY and load the output with 15kohm and measure. It really isn't that critical if you get 60V or 65V out.
/Kari
Gengis,
One thing you can do on the positive rail is to
increase the value and wattage of the R1
resistor on the power supply board. This will
lessen the heat the IRF610 will need to
dissipate, since there will be a greater
voltage drop across R1. Since R1 is part of
a CRC filter, it should also lower the
ripple on the positive rail.
Cheers,
Dennis
One thing you can do on the positive rail is to
increase the value and wattage of the R1
resistor on the power supply board. This will
lessen the heat the IRF610 will need to
dissipate, since there will be a greater
voltage drop across R1. Since R1 is part of
a CRC filter, it should also lower the
ripple on the positive rail.
Cheers,
Dennis
transformer issues...
I've got some similar transformer issues. I removed my BOSOZ Plitron transformers that are 60VA each with 60-0-60 (dual) secondaries and measured them this morning-- they measure 74-0-74! (ac volts)
What gives, is this because they are unloaded? Would you expect them to drop down to 60 under load or did I just receive the wrong shipment years ago?
I've got some similar transformer issues. I removed my BOSOZ Plitron transformers that are 60VA each with 60-0-60 (dual) secondaries and measured them this morning-- they measure 74-0-74! (ac volts)
What gives, is this because they are unloaded? Would you expect them to drop down to 60 under load or did I just receive the wrong shipment years ago?
Most likely a combination of winding tolerance, being unloaded and high line voltage. the 50 VA Plitrons advertise 13% regulation, so add 7.8 volts for being unloaded as opposed to pulling the rated current. They are wound for 115 volts - if you feed them 120 volts, add another 2.5 volts. I didn't see their tolerance on winding, but if they are 5% high, there is another 3 volts.
The question is are they useable? At 74 VAC, you'll get over 100VDC rectified. You might try a 10-20 ohm 3W resistor between the transformer and the PSU board, to reduce the voltage into the first cap.
The question is are they useable? At 74 VAC, you'll get over 100VDC rectified. You might try a 10-20 ohm 3W resistor between the transformer and the PSU board, to reduce the voltage into the first cap.
or...
Thanks Bob. Or I could just use a 160V capacitor at the 1st cap and up the R on the CRC filter.
Digikey has 160V snap in caps at 2700, 3300 and 3900 uF at about $9-11 each but I think some have the 4 pin snap-in package.
Anyone know if there is another source or 4700 uF 160V snap ins? Or know where a close value can be obtained cheaply?
Thanks Bob. Or I could just use a 160V capacitor at the 1st cap and up the R on the CRC filter.
Digikey has 160V snap in caps at 2700, 3300 and 3900 uF at about $9-11 each but I think some have the 4 pin snap-in package.
Anyone know if there is another source or 4700 uF 160V snap ins? Or know where a close value can be obtained cheaply?
Lgreen,
I wonder if it's absolutely necessary to go with 4700uF/160V
caps. The original BOSOZ power supply only has 1000uF
per rail before regulation and no CRC arrangement.
Until recently when I found a lower voltage transformer,
I was going to use some cheap 200VDC/1500uF caps
I found locally. Allowing for a lower cap value should
make sourcing easier.
Good luck,
Dennis
I wonder if it's absolutely necessary to go with 4700uF/160V
caps. The original BOSOZ power supply only has 1000uF
per rail before regulation and no CRC arrangement.
Until recently when I found a lower voltage transformer,
I was going to use some cheap 200VDC/1500uF caps
I found locally. Allowing for a lower cap value should
make sourcing easier.
Good luck,
Dennis
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