I used a tap to thread the holes and then fastened the fets to the heatsink with machine screws. Not hard.
Pinkmouse, another way to deal with the slight rise around the threaded hole is to use a "counter sink" tool and give it a few turns. Does a nice clean job ... quickly.
I, too, struggled with the capacitors at heat sink installation time and wound up using Greg's method (figured it out on my own) of heating the caps and moving them very slightly. Worked.
Bill
Pinkmouse, another way to deal with the slight rise around the threaded hole is to use a "counter sink" tool and give it a few turns. Does a nice clean job ... quickly.
I, too, struggled with the capacitors at heat sink installation time and wound up using Greg's method (figured it out on my own) of heating the caps and moving them very slightly. Worked.
Bill
ska diagrams
Macka,
My thanks to you and Greg for the diagrams posted in this thread - especially the first. At first glance it looked identical to that included in the instructions Greg sent but closer inspection showed some very pertinent enhancements (especially from the point of view of a newbie).
Looking forward to the arrival of the kit!
Roman
Macka,
My thanks to you and Greg for the diagrams posted in this thread - especially the first. At first glance it looked identical to that included in the instructions Greg sent but closer inspection showed some very pertinent enhancements (especially from the point of view of a newbie).
Looking forward to the arrival of the kit!
Roman
Hi all,
I just got around to assembling my GB150D kit - it's a breeze and for a not hugely experienced solderer it took me about 1.5 hrs for one board.
I'm just at the end and I wanted to check the final instruction on the correct connection of the D5 D6 thermal trannies to the board connections underneath - the included assembly instructions for connection are - "The white wire on each connects the single (emitter) pin (RH pin on underside) to the supply rail (outer) terminal near Q6 or 8"
So I assume with the board turned over that the wire wire connects to the RH pin of D8 and then to the outer pin just above Q6 (this is marked - on the circuit diag). However, the outer pin above Q8 is marked positive, so should I be connecting to outer pins for both cases?
Maybe a photo of the underside of board would clear this up?
John
I just got around to assembling my GB150D kit - it's a breeze and for a not hugely experienced solderer it took me about 1.5 hrs for one board.
I'm just at the end and I wanted to check the final instruction on the correct connection of the D5 D6 thermal trannies to the board connections underneath - the included assembly instructions for connection are - "The white wire on each connects the single (emitter) pin (RH pin on underside) to the supply rail (outer) terminal near Q6 or 8"
So I assume with the board turned over that the wire wire connects to the RH pin of D8 and then to the outer pin just above Q6 (this is marked - on the circuit diag). However, the outer pin above Q8 is marked positive, so should I be connecting to outer pins for both cases?
Maybe a photo of the underside of board would clear this up?
John
Maybe, I just got it -
On turned over board right pin on D5 is +(pos) and this goes to the outside pin above Q8 also +(pos)
Right pin on D6 is -(neg) and this goes to outside pin above Q6 also -(neg)
Is that correct?
I didn't want to bother Greg with a trivial email like this as I'm sure he is very busy at the moment fulfilling orders and I thought posted here it might help future neophytes in the only area of doubt I had with the instructions
John
On turned over board right pin on D5 is +(pos) and this goes to the outside pin above Q8 also +(pos)
Right pin on D6 is -(neg) and this goes to outside pin above Q6 also -(neg)
Is that correct?
I didn't want to bother Greg with a trivial email like this as I'm sure he is very busy at the moment fulfilling orders and I thought posted here it might help future neophytes in the only area of doubt I had with the instructions
John
SKA Amp Wiring Question
Greetings Everyone,
Being my first project, I was hoping to ask for some opinions on whether or not the wiring I am planning for this project looks good so far. I will be receiving two assembled and tested amplifier modules and two assembled and tested power supply modules. A quick background may be helpful to explain how I plan to proceed. I have a 330VA transformer with dual 35V secondaries and the transformer information is contained on the attached slide. The transformer came with no documentation, save a picture on its side that I reproduced on the attached diagram. I hope to wire the transformer primaries in parallel and then attach each secondary independently to a GB150ABS power supply module.
If anyone with experience could offer their thoughts on whether my current wiring scheme is sound, I would appreciate it. Also, feel free to edit/add to the diagram as it may help others in the same predicament.
Thanks in advance for any assistance,
Regards,
Chad
Greetings Everyone,
Being my first project, I was hoping to ask for some opinions on whether or not the wiring I am planning for this project looks good so far. I will be receiving two assembled and tested amplifier modules and two assembled and tested power supply modules. A quick background may be helpful to explain how I plan to proceed. I have a 330VA transformer with dual 35V secondaries and the transformer information is contained on the attached slide. The transformer came with no documentation, save a picture on its side that I reproduced on the attached diagram. I hope to wire the transformer primaries in parallel and then attach each secondary independently to a GB150ABS power supply module.
If anyone with experience could offer their thoughts on whether my current wiring scheme is sound, I would appreciate it. Also, feel free to edit/add to the diagram as it may help others in the same predicament.
Thanks in advance for any assistance,
Regards,
Chad
ska wiring diagram
Hi Chad, Very good question and attachment! I'm building an amp with the identical topology to yours (transformer is a 300VA with 35 V secondaries from Plitron) and have been pondering precisely the same connectivity questions.
For anyone responding, the diagram method Chad used was most useful in making the question and problem very clear (at least to moi, a newbie). No doubt the same approach for a solution would be deluxe!
Thanks,
Roman
Hi Chad, Very good question and attachment! I'm building an amp with the identical topology to yours (transformer is a 300VA with 35 V secondaries from Plitron) and have been pondering precisely the same connectivity questions.
For anyone responding, the diagram method Chad used was most useful in making the question and problem very clear (at least to moi, a newbie). No doubt the same approach for a solution would be deluxe!
Thanks,
Roman
Hi,
Connect red and orange.
Check the voltage across black and yellow. It should be about 74Vac with nothing else connected.
If OK then proceed.
Connect black to ~ on both PSU inputs.
Connect yellow to ~ on both PSU inputs.
Connect a wire (preferably green not yellow/green) from the red and orange junction to the commons on both the PSU inputs. You may want to use a terminal strip for these interconnections.
Remember to bolt or weld the incoming earth (safety) wire to the metal chassis and NEVER remove it whenever you are connected to the mains supply.
I cannot recall where Amp guru recommends you take the PSU ground from but follow his instructions.
Before powering up for the first time wire a mains rated light bulb in series with the primary supply.
A bulb, socket and plug top assembly can be held in store for all your initial testing. Just plug it into the mains and then feed your new equipment from the trailing socket. The bulb may initially flash and go out or flash and go dim or flash and stay on,
If it stays on, post us.
Connect red and orange.
Check the voltage across black and yellow. It should be about 74Vac with nothing else connected.
If OK then proceed.
Connect black to ~ on both PSU inputs.
Connect yellow to ~ on both PSU inputs.
Connect a wire (preferably green not yellow/green) from the red and orange junction to the commons on both the PSU inputs. You may want to use a terminal strip for these interconnections.
Remember to bolt or weld the incoming earth (safety) wire to the metal chassis and NEVER remove it whenever you are connected to the mains supply.
I cannot recall where Amp guru recommends you take the PSU ground from but follow his instructions.
Before powering up for the first time wire a mains rated light bulb in series with the primary supply.
A bulb, socket and plug top assembly can be held in store for all your initial testing. Just plug it into the mains and then feed your new equipment from the trailing socket. The bulb may initially flash and go out or flash and go dim or flash and stay on,
If it stays on, post us.
Thanks for the replies thus far, and Rez, glad it is of use to you as well in your project. I think what I have heard from the posts so far is:
1. The transformer primaries wired in parallel for 110V are fine as is.
2. For the secondaries, they can't be used independently. In other words, since one transformer is feeding two power supplies, two wires from one secondary can't supply one power supply and the remaining two secondary wires can't supply the other power supply. The secondaries will need to be configured either in parallel or series and then fed to both power supplies.
I seem to have two options to wire the secondaries, in parallel or in series. Since I am connecting two power supplies, is it required to use parallel wiring on the secondaries rather than series or vice versa? If anyone could clear this question up I would appreciate it and will then try to finalize the diagram in case a completed schematic would be of use to anyone.
Thanks in advance,
Regards,
Chad
1. The transformer primaries wired in parallel for 110V are fine as is.
2. For the secondaries, they can't be used independently. In other words, since one transformer is feeding two power supplies, two wires from one secondary can't supply one power supply and the remaining two secondary wires can't supply the other power supply. The secondaries will need to be configured either in parallel or series and then fed to both power supplies.
I seem to have two options to wire the secondaries, in parallel or in series. Since I am connecting two power supplies, is it required to use parallel wiring on the secondaries rather than series or vice versa? If anyone could clear this question up I would appreciate it and will then try to finalize the diagram in case a completed schematic would be of use to anyone.
Thanks in advance,
Regards,
Chad
Andrew,
Your first post was most helpful, thanks. At the risk of being unintentionally obdurate, I had been advised by another hobbyist to use a parallel connection on the secondaries in lieu of the series configuration you recommended. The hobbyist was under the impression that one transformer was being used with one power supply. Not understanding the full voltage implications of each option with the secondaries, I was hoping to cement my understanding (and I agree with you, it is very basic at this point having no background to date in EE or anything electrical), and avoid a barbecue in the chassis when I power on. I was just hoping to clarify if the wiring conficuration of the secondaries changes depending on the number of power suppleis you connect the transformer to.
Thanks again for your replies, I believe I have the answer and will move forward with your recommendation.
Regards,
Chad
Your first post was most helpful, thanks. At the risk of being unintentionally obdurate, I had been advised by another hobbyist to use a parallel connection on the secondaries in lieu of the series configuration you recommended. The hobbyist was under the impression that one transformer was being used with one power supply. Not understanding the full voltage implications of each option with the secondaries, I was hoping to cement my understanding (and I agree with you, it is very basic at this point having no background to date in EE or anything electrical), and avoid a barbecue in the chassis when I power on. I was just hoping to clarify if the wiring conficuration of the secondaries changes depending on the number of power suppleis you connect the transformer to.
Thanks again for your replies, I believe I have the answer and will move forward with your recommendation.
Regards,
Chad
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.