I use a rarely mentioned invention, called a powersupply for short PSU, to solve that problem.
Or maybe this Multiple-purpose power supply after computer is switched off - US Patent Application 20050050368 Description
Whilst on the subject of swaps...
In my GB bag i did not receive any 147K resistors but I did get 4x 2k resistors that I don't think are anywhere on the boards. I also received 16x 150k when I only needed 4x.
Did anyone get more 147k than they needed and could they swap with me or if you don't need any swaps could you send me their spare 147's please?
In my GB bag i did not receive any 147K resistors but I did get 4x 2k resistors that I don't think are anywhere on the boards. I also received 16x 150k when I only needed 4x.
Did anyone get more 147k than they needed and could they swap with me or if you don't need any swaps could you send me their spare 147's please?
Ok this is driving me nuts.
Has anyone completed a build using the R3 boards and the group buy parts? Cos all I have is two populated pcb's and not a single damn LED that lights up. Yes all Leds are correct way round and all are working when tested with Atlas DCR.
All 327 and 337 are correctly placed and everything else is in the right place.
Has anyone completed a build using the R3 boards and the group buy parts? Cos all I have is two populated pcb's and not a single damn LED that lights up. Yes all Leds are correct way round and all are working when tested with Atlas DCR.
All 327 and 337 are correctly placed and everything else is in the right place.
Yet, something clearly is not in the right place. Check again.
If leds are not alight, your CCS is not working. Correct devices on the sink?
Input power ok?
There is no much difference between R3 and R2
Just a couple of footprints for J fets (easier on R3) and the input offset that is now on top of the board
Easy done to place a PNP in place of NPN and to get a capacitor the wrong way around
Did that myself
I wuld triple look at the transistors under the heath sink as well
Just a couple of footprints for J fets (easier on R3) and the input offset that is now on top of the board
Easy done to place a PNP in place of NPN and to get a capacitor the wrong way around
Did that myself
I wuld triple look at the transistors under the heath sink as well
Seriously guys, everything is in the right place. All the caps and LED's are the right way round and all the transistors are correctly placed. I've removed the heatsinks and checked everything.
I'll probe some voltages when i get back from my folks after Xmas.
It would be really nice if anyone else from the large group buy could say they had built the psu section on theirs and it worked.
I'll probe some voltages when i get back from my folks after Xmas.
It would be really nice if anyone else from the large group buy could say they had built the psu section on theirs and it worked.
Hello,
I think I need some help from you.
I built up the preregulator according to Joachims schematic:
http://www.diyaudio.com/forums/group-buys/222164-paradise-phono-preregulator-4.html#post3219654
I have a 240 V 2x24 V transformer which measures 27,6 V ac each secondary.
The chokes are in place.
Now I have 37,3 V dc between plus vdc and ground, and -37,3 V dc between
minus vdc and ground, 74,6 V dc between plus vdc and minus vdc.
I also have plus/minus 81,5 V AC between plus/minus vdc and ground and
163 V AC between plus vdc and minus vdc.
I am not sure this will be right and have fear to power up the paradise with this unit.
Thanks a lot,
Christoph
I think I need some help from you.
I built up the preregulator according to Joachims schematic:
http://www.diyaudio.com/forums/group-buys/222164-paradise-phono-preregulator-4.html#post3219654
I have a 240 V 2x24 V transformer which measures 27,6 V ac each secondary.
The chokes are in place.
Now I have 37,3 V dc between plus vdc and ground, and -37,3 V dc between
minus vdc and ground, 74,6 V dc between plus vdc and minus vdc.
I also have plus/minus 81,5 V AC between plus/minus vdc and ground and
163 V AC between plus vdc and minus vdc.
I am not sure this will be right and have fear to power up the paradise with this unit.
Thanks a lot,
Christoph
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Could you make a little drawing on paper with the circuit you build, scan it in and post it.
163V AC between plus/minus is a lot. Do you measure with a very high impedance DMM ?
What you could try is ballast the pre regulator with dummy resistors.
Say you want to draw ca. 50mA. Then you have 37,3 V / 0,05A = ca. 750 Ohm.
This resistors have to withstand at least 2W. The DC voltage will drop a bit.
Please remeasure AC voltage after you have put the resistors in place.
163V AC between plus/minus is a lot. Do you measure with a very high impedance DMM ?
What you could try is ballast the pre regulator with dummy resistors.
Say you want to draw ca. 50mA. Then you have 37,3 V / 0,05A = ca. 750 Ohm.
This resistors have to withstand at least 2W. The DC voltage will drop a bit.
Please remeasure AC voltage after you have put the resistors in place.
Hello Joachim,
thanks for your reply.
It is just the schematic you posted and I have linked.
My dmm is a simple Peaktech 1075 PEAKTECH 1075 - Digital-Multimeter 3 -stellig, Spannungsdetektor bei reichelt elektronik
I have to buy the resistors you recommend, have no spares in this value.
The transformer is connected with both secondaries to the inputs.
Regards,
Christoph
thanks for your reply.
It is just the schematic you posted and I have linked.
My dmm is a simple Peaktech 1075 PEAKTECH 1075 - Digital-Multimeter 3 -stellig, Spannungsdetektor bei reichelt elektronik
I have to buy the resistors you recommend, have no spares in this value.
The transformer is connected with both secondaries to the inputs.
Regards,
Christoph
I checked my schematic and when you have build it that way it should work fine.
It could be that there is some inductive coupling between the coils when you have put them too close together.
You can make your own high wattage resistor by paralleling some. Say you use 5kOhm 1/4 W resistors. You can parallel 10 to get 500 Ohm. That value is alright too.
It could be that there is some inductive coupling between the coils when you have put them too close together.
You can make your own high wattage resistor by paralleling some. Say you use 5kOhm 1/4 W resistors. You can parallel 10 to get 500 Ohm. That value is alright too.