I need to upgrade the schmatics, as the positive and negative part of the PCB does not share ground.
I will redraw the schmatics toight after work, but the board is ok the way it is I think.
They will need to have a common ground somewhere, either on the PSU board or the filter board.
\Jens
I will redraw the schmatics toight after work, but the board is ok the way it is I think.
They will need to have a common ground somewhere, either on the PSU board or the filter board.
\Jens
Hello all,
In the last couple of pages a opinions on a couple of design decision were asked, so here goes:
I don't need a LED as I have plenty of them around in red green and blue.
For my purposes 1200uF of capacitance is enough.
If scoring adds to the cost of the boards than that's not needed (hey I'm ME so a hacksaw is what I can use (oscilloscopes on the other hand.......)).
If the group (or Jens and Bob) decides otherwise, that's alright as well.
Regards,
Jarno.
In the last couple of pages a opinions on a couple of design decision were asked, so here goes:
I don't need a LED as I have plenty of them around in red green and blue.
For my purposes 1200uF of capacitance is enough.
If scoring adds to the cost of the boards than that's not needed (hey I'm ME so a hacksaw is what I can use (oscilloscopes on the other hand.......)).
If the group (or Jens and Bob) decides otherwise, that's alright as well.
Regards,
Jarno.
Ordering
I have heard from 31 of 70 who expressed interest on the WIKI or privately.
For those who have not confirmed, please let me know whether you are interested or not.
Send email to robert (dot) e (dot) ellis ( at ) Verizon (dot) net with the subject line "Group Buy"
including your:
DiyAudio?? Name
Real Name
Shipping address
telephone number (USPS wants this for international shipments)
Number of Filter boards @ $5
Number of PSU boards @ $5
Number of PSU parts kits @ $20.25
Number of Heat sink pairs @ $1.80 (if you are buying OPAs from gengis he can combine with that order)
Number of Tranformers (Price tbd, $16.50 or less)
Number of extra Panasonic FC 470 uf 25V 10 mm od x 5 mm lead spacing. (fits active filter board) Order in increments of 10 pieces, please.
Number of extra Epcos MKT 100 nf 63V 2.5 mm x 7.5 mm x 5 mm lead spacing. (fits active filter board) Order in increments of 10 pieces, please.
I will send invoices beginning this weekend. Transformer price will be based on the number of orders received by Friday 7 April.
Bob
I have heard from 31 of 70 who expressed interest on the WIKI or privately.
For those who have not confirmed, please let me know whether you are interested or not.
Send email to robert (dot) e (dot) ellis ( at ) Verizon (dot) net with the subject line "Group Buy"
including your:
DiyAudio?? Name
Real Name
Shipping address
telephone number (USPS wants this for international shipments)
Number of Filter boards @ $5
Number of PSU boards @ $5
Number of PSU parts kits @ $20.25
Number of Heat sink pairs @ $1.80 (if you are buying OPAs from gengis he can combine with that order)
Number of Tranformers (Price tbd, $16.50 or less)
Number of extra Panasonic FC 470 uf 25V 10 mm od x 5 mm lead spacing. (fits active filter board) Order in increments of 10 pieces, please.
Number of extra Epcos MKT 100 nf 63V 2.5 mm x 7.5 mm x 5 mm lead spacing. (fits active filter board) Order in increments of 10 pieces, please.
I will send invoices beginning this weekend. Transformer price will be based on the number of orders received by Friday 7 April.
Bob
Each filter board has 2 spots for 470 uF caps.
100 nf can be used for bypass at the chips and some of the filter positions. Fully stuffed, this would be 18 for bypass and maybe another 10-12 for filter use (these are 5% so if using them for filter postions you'll need to measure and pick the closest ones or adjust resistors)
100 nf can be used for bypass at the chips and some of the filter positions. Fully stuffed, this would be 18 for bypass and maybe another 10-12 for filter use (these are 5% so if using them for filter postions you'll need to measure and pick the closest ones or adjust resistors)
Jens did some testing today in the current configuration (just capacitive input filter) and the regulator works well with just 15V in.
The group buy transformers are back to 15V.
Also there were a couple of minor changes to the layout that I will post later. They were:
Added two film capacitors to the output. (they had been dropped initially when Jens made room for the bigger output caps.)
Rotated the input and output terminals 90 degrees to allow easier access.
Yes, I have a day job. I just took advantage of a bit of insomnia.
The group buy transformers are back to 15V.
Also there were a couple of minor changes to the layout that I will post later. They were:
Added two film capacitors to the output. (they had been dropped initially when Jens made room for the bigger output caps.)
Rotated the input and output terminals 90 degrees to allow easier access.
Yes, I have a day job. I just took advantage of a bit of insomnia.
Hi,
Bob is that 10mA/opamp allowance just the quiescent current or some to the load?
Some current goes to the feedback network, some feeds load resistors and some high frequency is used to charge up any caps on the output.
With typical LO & HI pass filters what allowance/opamp needs to be added to Iq?
Are the current requirements of equalisation similar?
I would expect each single opamp to need less than an additional 10mA. A dual chip then needs <30mA and a fully populated board <270mA.
Calculation or real life measurement should be able to trim these figures.
Bob is that 10mA/opamp allowance just the quiescent current or some to the load?
Some current goes to the feedback network, some feeds load resistors and some high frequency is used to charge up any caps on the output.
With typical LO & HI pass filters what allowance/opamp needs to be added to Iq?
Are the current requirements of equalisation similar?
I would expect each single opamp to need less than an additional 10mA. A dual chip then needs <30mA and a fully populated board <270mA.
Calculation or real life measurement should be able to trim these figures.
Yes, 10 mA per opamp is the quiescent current. Being a practical guy, I figure with frequency setting resistors and loads in the few K range maybe 5-10% is enough, rather than calculate each one.
If you're trying to drive 600 ohm loads, you need to pay more attention to actual current draw.
If you're trying to drive 600 ohm loads, you need to pay more attention to actual current draw.
I have received payment for 38 of 58 confirmed orders. Thank You to the prompt.
As before, I will order a few extras of everything, but I will not be able to cover even all the confirmed orders, much less all signed up. I will have enough for those who have made arrangements with me privately.
The following signed up on the WIKI but have not told me if they are still interested.
405man
BFNY
cambe
chipco3434
Cobra2
cotdt
DavidS
giannettino
gozierdt
jackh
pool
tg3
UrSv
Variac
Vinnie
Please let me know if you are still interested so I don't shut you out of the buy if you really wanted to participate. If you will not participate, I'd appreciate a note to that effect.
My thanks to those of you who took the time to tell me you will not participate.
As before, I will order a few extras of everything, but I will not be able to cover even all the confirmed orders, much less all signed up. I will have enough for those who have made arrangements with me privately.
The following signed up on the WIKI but have not told me if they are still interested.
405man
BFNY
cambe
chipco3434
Cobra2
cotdt
DavidS
giannettino
gozierdt
jackh
pool
tg3
UrSv
Variac
Vinnie
Please let me know if you are still interested so I don't shut you out of the buy if you really wanted to participate. If you will not participate, I'd appreciate a note to that effect.
My thanks to those of you who took the time to tell me you will not participate.
Mike,
One power supply will handle 4 boards if you use heat sinks, or two without when using 15VAC input. The boards need a transformer with 2 separate windings, not a 15-0-15 center tapped transformer.
The parts kit includes everything you need for +/- 15V nominal operation except heat sinks and transformer. The reference and voltage setting resistors are 1%, so you should be pretty darned close right off the bat.
If you want to trim the voltages to exactly 15V you'll need two trim pots and a resistor change (both with and without trim pot resistors are included in kit.) You can use just one trim pot and just make the voltages the same.
One power supply will handle 4 boards if you use heat sinks, or two without when using 15VAC input. The boards need a transformer with 2 separate windings, not a 15-0-15 center tapped transformer.
The parts kit includes everything you need for +/- 15V nominal operation except heat sinks and transformer. The reference and voltage setting resistors are 1%, so you should be pretty darned close right off the bat.
If you want to trim the voltages to exactly 15V you'll need two trim pots and a resistor change (both with and without trim pot resistors are included in kit.) You can use just one trim pot and just make the voltages the same.
Hi,
although it defeats the dual rectifier layout it should be very easy to use a centre tapped transformer and omit four diodes to use this board.
I await my PCBs before describing this mod in detail. It's what I intend doing. I just wish that the extra R of CRC had been kept with the option to link it out for those that wanted just C smoothing.
although it defeats the dual rectifier layout it should be very easy to use a centre tapped transformer and omit four diodes to use this board.
I await my PCBs before describing this mod in detail. It's what I intend doing. I just wish that the extra R of CRC had been kept with the option to link it out for those that wanted just C smoothing.
AndrewT said:
Andrew,
If you want the schematic file from eagle I'd be happy to mail it to you or any other for a different project.... Maybe you can fit the circuit better on the board, but as 10x8 cm was a major requirement for the non licensed users of eagle I had to limit the space used.
The 1 ohm resistor would mean that a 10VAC transformer was needed and thus also a heatsink.... I don’t really se the reason for using the CRC filter as I have below 10mVpp ripple on the output when it is loaded with 750mA and being fed from a 2x15V AC 50VA transformer.
10mVpp is 49 dB down compared a 2V RMS signal.
Regarding the centre tapped transformer, you must connect the two ground planes of each regulator as they are not connected on the PCB.
\Jens
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