For the IRFP240, that is what is recommended by others. It is the most commonly used transistor for DIY Aleph designs. The IRF240 is a TO3 version of the IRFP240, which is the plastic TO-247AC package. I believe that Mr. Pass recommended the IRFP240 in a couple of posts.
I will definately consider making the output boards, once I finish the main boards.
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Brian
gte619j@prism.gatech.edu
I will definately consider making the output boards, once I finish the main boards.
--
Brian
gte619j@prism.gatech.edu
Brian,
IRF240 is the TO3 version ....... is this the metal case type? ..... if it is, it might not work with the output board (assuming you're using Wayne's) ....... and also how do you mount the TO3 onto the heatsink? .....unless you're planning on mounting them to some other metal and then to the heatsink ...... just wondering ....
IRF240 is the TO3 version ....... is this the metal case type? ..... if it is, it might not work with the output board (assuming you're using Wayne's) ....... and also how do you mount the TO3 onto the heatsink? .....unless you're planning on mounting them to some other metal and then to the heatsink ...... just wondering ....
The IRF240 is the metal case type, which basically went the way of obsolescence. The IRFP240 is the replacement used by most people. I have 125 IRFP240 units that I am matching this Friday. I should have some extra sets, as I just need 24 for myself, and 24 for a friend. I should easily have 2 more sets of 24. For matching, you need 2 matched sets of 6 per channel.
I initially wanted to get some IRF240, but since they are not widely available anymore (irf says they still make them, but no one has them), they were a lot more expensive. I think that only person who has a large collection of them still is Mr. Pass. I had some TO-3 heatsinks that I was considering using before, but I have since gotten better flat heatsinks, that I can easily screw the IRFP240 units to.
Another interesting case is the IRFM240, which is the same size as the IRFP240, but metal instead of plastic. The government uses these in high reliability applications. I priced these out from a few vendors, and they ended up costing $40 each.
--
Brian
gte619j@prism.gatech.edu
I initially wanted to get some IRF240, but since they are not widely available anymore (irf says they still make them, but no one has them), they were a lot more expensive. I think that only person who has a large collection of them still is Mr. Pass. I had some TO-3 heatsinks that I was considering using before, but I have since gotten better flat heatsinks, that I can easily screw the IRFP240 units to.
Another interesting case is the IRFM240, which is the same size as the IRFP240, but metal instead of plastic. The government uses these in high reliability applications. I priced these out from a few vendors, and they ended up costing $40 each.
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Brian
gte619j@prism.gatech.edu
fcel, just to clarify, I have the same exact output transistors as Wayne Sankey used for his Aleph 2, the IRFP240.
--
Brian
gte619j@prism.gatech.edu
--
Brian
gte619j@prism.gatech.edu
I want my pcb's
Hey, I am interested in keeping costs down, BUT if it costs me $4 extra to get thicker traces, thick substrate, ground plane (if that actually helps) screened componant labeling, etc I'm happy to do so. These are high end devices we are making after all.
I agree the power board is the least important- in fact I don't want one.
Really exciting that this amp will now happen!!
Mark
Hey, I am interested in keeping costs down, BUT if it costs me $4 extra to get thicker traces, thick substrate, ground plane (if that actually helps) screened componant labeling, etc I'm happy to do so. These are high end devices we are making after all.
I agree the power board is the least important- in fact I don't want one.
Really exciting that this amp will now happen!!
Mark
I have looked several places. All of them that I have found only seem to offer 2 layer boards and up.
The cheapest place that I have found, and I know a teacher at school who used it for some boards, is ExpressPCB.com
I am redesigning the board now, because I want to have heatsinks on Q1,Q2 and Q3. I also want some better routing. I am doing it with the ExpressPCB.com program now, and I can later redo it in a Gerber program, if another place is chosen. I should be done the layout tonight, and I will post it for others to see. That board will be a dual layer board, but so far, I have done all of the traces on one layer, so that I can use the same design for a single layer board, should I decide to do that. I am talking to Prof. Leach soon, and will find out where he gets his boards made. If the ExpressPCB route is taken, then the extra layer can be used for ground.
I am really interested in getting this done, as I am tired of waiting for someone else to do it
I am open to any suggestions. When I finish, I will post my layout for everyone to have, and get boards made on their own, if they choose so, and do not get in on the initial order.
I am pretty sure that I will just do the main board, as point to point wiring is pretty easy for the power boards, and the configuration that I am personally doing would require 4 boards of 3 output devices (3 per heatsink).
I can make a design for the output boards, and others can get an order going, when I finish this and have time.
I found out one more option today, is that here at Georgia Tech, they have their own board fabrication facility, so I might be able to bring them my gerber files and pay for the cost of materials and have a small run of boards made.
As for silk screening, it really adds to the cost, and due to the simple nature of the board, it really is not needed. A picture of the silkscreen layer will be available, for making the boards.
I will keep everyone posted.
--
Brian
gte619j@prism.gatech.edu
The cheapest place that I have found, and I know a teacher at school who used it for some boards, is ExpressPCB.com
I am redesigning the board now, because I want to have heatsinks on Q1,Q2 and Q3. I also want some better routing. I am doing it with the ExpressPCB.com program now, and I can later redo it in a Gerber program, if another place is chosen. I should be done the layout tonight, and I will post it for others to see. That board will be a dual layer board, but so far, I have done all of the traces on one layer, so that I can use the same design for a single layer board, should I decide to do that. I am talking to Prof. Leach soon, and will find out where he gets his boards made. If the ExpressPCB route is taken, then the extra layer can be used for ground.
I am really interested in getting this done, as I am tired of waiting for someone else to do it
I am open to any suggestions. When I finish, I will post my layout for everyone to have, and get boards made on their own, if they choose so, and do not get in on the initial order.
I am pretty sure that I will just do the main board, as point to point wiring is pretty easy for the power boards, and the configuration that I am personally doing would require 4 boards of 3 output devices (3 per heatsink).
I can make a design for the output boards, and others can get an order going, when I finish this and have time.
I found out one more option today, is that here at Georgia Tech, they have their own board fabrication facility, so I might be able to bring them my gerber files and pay for the cost of materials and have a small run of boards made.
As for silk screening, it really adds to the cost, and due to the simple nature of the board, it really is not needed. A picture of the silkscreen layer will be available, for making the boards.
I will keep everyone posted.
--
Brian
gte619j@prism.gatech.edu
Looks like pcb-pool is located in Ireland, and apcircuits is located in Alberta Canada. This may be helpful to others in those countries, but it seems like higher shipping and more hassle from the US.
If you find any cheaper places in the US, let me know.
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Brian
gte619j@prism.gatech.edu
If you find any cheaper places in the US, let me know.
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Brian
gte619j@prism.gatech.edu
Anyone interested in getting a set of Aleph 2 main boards, please e-mail me with how many you want and your contact information.
Please make the subject "Aleph pcb boards". I am trying to get an organized list, since it is a little difficult on the forum.
Thanks,
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Brian
gte619j@prism.gatech.edu
Please make the subject "Aleph pcb boards". I am trying to get an organized list, since it is a little difficult on the forum.
Thanks,
--
Brian
gte619j@prism.gatech.edu
BrianGT:
OK, so APCircuits charge $25 to ship.......that's a bit, but over this many people isn't too bad given their other low costs.
Not sure on pcb-pool's shipping deal but their prices are VERY good also. ExpressPCB requires you use their own software and do not offer nearly as good prices as far as I can see.
OK, so APCircuits charge $25 to ship.......that's a bit, but over this many people isn't too bad given their other low costs.
Not sure on pcb-pool's shipping deal but their prices are VERY good also. ExpressPCB requires you use their own software and do not offer nearly as good prices as far as I can see.
I talked to Prof. Leach for a couple of hours today and found a local place that he uses for his boards. I need to make the boards in Gerber format. I have access to a version of Orcad layout. Does anyone know any simplier programs to use? I currently have the board layout made in the PCB express program, just to get a basic layout. Does anyone know an easy gerber layout program, similar to PCB express?
That boards from the place, Empire Electronics will be single sided with these options:
(anyone have any preferences? if not, I will use the same options as Prof. Leach uses for his Leach Amp boards)
Type:
FR1/CEM-1/CEM-3
Thickness:
0.5/1/2/3/4oz
Color:
Green/Blue/Red/Black
Silk screening is available.
This place should be pretty cheap, if I can get them to do a small enough quantity.
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Brian
gte619j@prism.gatech.edu
That boards from the place, Empire Electronics will be single sided with these options:
(anyone have any preferences? if not, I will use the same options as Prof. Leach uses for his Leach Amp boards)
Type:
FR1/CEM-1/CEM-3
Thickness:
0.5/1/2/3/4oz
Color:
Green/Blue/Red/Black
Silk screening is available.
This place should be pretty cheap, if I can get them to do a small enough quantity.
--
Brian
gte619j@prism.gatech.edu
Before I post my board layout, can someone make sure my schematic is correct. I put red dots on the connections, as there were none. I believe I have it correct.
I referenced this off the Aleph 4 circuit.
aleph 2 circuit
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Brian
gte619j@prism.gatech.edu
I referenced this off the Aleph 4 circuit.
aleph 2 circuit
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Brian
gte619j@prism.gatech.edu
one more question on the circuit:
Should C7 be across collector base, as shown in the Aleph 2 schematic, or should it be across collector emitter, as shown in the Aleph, 1.2, 4 and 5 schematic?
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Brian
gte619j@prism.gatech.edu
Should C7 be across collector base, as shown in the Aleph 2 schematic, or should it be across collector emitter, as shown in the Aleph, 1.2, 4 and 5 schematic?
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Brian
gte619j@prism.gatech.edu
C10 is attached on the bottom, and not the top, right? I will add that connection when I get home.
As for the 4oz, I was just relaying the options. I would not think that boards would be made with more then 2 oz for the case of the Aleph.
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Brian
gte619j@prism.gatech.edu
As for the 4oz, I was just relaying the options. I would not think that boards would be made with more then 2 oz for the case of the Aleph.
--
Brian
gte619j@prism.gatech.edu
I spoke to Empire Electronics today, and they have a high setup cost, but the boards get pretty cheap.
The setup cost is $195, with you giving them the board file in Gerber data. He estimated that 15 boards can be fit one one big board.
Then the board cost:
$10 each for 15
$8 each for 30
It gets cheaper with more boards. This is for green boards 1 oz with soldier mask. The boards are the minimal cost, so they can be upgraded to 2 oz, or silkscreening for not too much extra.
That means for 7 people, the cost would be $50 a person for 2 boards. For 15 people, the cost would be $29 for 2 boards. For 30 people, the cost would be under $20 for 2 boards. Professor Leach purchased 100 leach amp boards, and his cost was $15 for 2 boards
Once you pay the initial setup charge, you can get boards made whenever you want again with no setup charge, since the board will be in the system. All that would be needed to be done is someone to call the place and order more boards.
I will post the board layout tonight, for people to look over and check. I will need some help making the board in Gerber format, or suggestions on what program to use. I am working on it in the PCBExpress program, and I have tried using Orcad Layout, but I haven't learned the program too well yet.
--
Brian
gte619j@prism.gatech.edu
The setup cost is $195, with you giving them the board file in Gerber data. He estimated that 15 boards can be fit one one big board.
Then the board cost:
$10 each for 15
$8 each for 30
It gets cheaper with more boards. This is for green boards 1 oz with soldier mask. The boards are the minimal cost, so they can be upgraded to 2 oz, or silkscreening for not too much extra.
That means for 7 people, the cost would be $50 a person for 2 boards. For 15 people, the cost would be $29 for 2 boards. For 30 people, the cost would be under $20 for 2 boards. Professor Leach purchased 100 leach amp boards, and his cost was $15 for 2 boards
Once you pay the initial setup charge, you can get boards made whenever you want again with no setup charge, since the board will be in the system. All that would be needed to be done is someone to call the place and order more boards.
I will post the board layout tonight, for people to look over and check. I will need some help making the board in Gerber format, or suggestions on what program to use. I am working on it in the PCBExpress program, and I have tried using Orcad Layout, but I haven't learned the program too well yet.
--
Brian
gte619j@prism.gatech.edu
PCBs
Brian
Is there any choice for the substrate or whatever the fiberglass part is called. I would be interested in getting that thick to cut down on resonances. Also the screened layer is pretty cool if it is cheap and you don't have to do extra work.
Any of the options discussed are ultimately fine with me, so don't stress over our various requests. you are almost a saint in my opinion for keeping us in the loop so we benefit from this!
Cheap is always important if the quality is good!
It is cool that the set up charge is a one time thing. You are being very generous to not charge us anything additional, BUT in the future you could put a notice in the trading post and when you got enough orders get another batch and sell them for a modest profit. Or order and pay for a few extra this time. You know that more people will want some as soon as the order is finalized!
How many people have e-mailed you to sign up?
Mark
Brian
Is there any choice for the substrate or whatever the fiberglass part is called. I would be interested in getting that thick to cut down on resonances. Also the screened layer is pretty cool if it is cheap and you don't have to do extra work.
Any of the options discussed are ultimately fine with me, so don't stress over our various requests. you are almost a saint in my opinion for keeping us in the loop so we benefit from this!
Cheap is always important if the quality is good!
It is cool that the set up charge is a one time thing. You are being very generous to not charge us anything additional, BUT in the future you could put a notice in the trading post and when you got enough orders get another batch and sell them for a modest profit. Or order and pay for a few extra this time. You know that more people will want some as soon as the order is finalized!
How many people have e-mailed you to sign up?
Mark
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