Hey, guys I finished measurements, so now I need to take a look at the numbers and pair them together, order some other parts and put everything together in nice packaging so everyone will know what is what... Go easy on me I just recovered from Covid...My holidays were mostly spent on my couch watching TV...
So to all happy new year and I hope I can finish this project as fast as I can..
So to all happy new year and I hope I can finish this project as fast as I can..
What is going to happen is that ONE "reject" set will be sent to Fran.
He will do a Beta build and test to make sure everything is as they should be.
Then Ripster can ship to you, and Fran will write and distribute building instructions.
What service !!!!!
Patrick
He will do a Beta build and test to make sure everything is as they should be.
Then Ripster can ship to you, and Fran will write and distribute building instructions.
What service !!!!!
Patrick
So guys, hope this GB is on its last meters toward the finish line... It is been quite a journey 😀
Just need to wait for a test build and if everything OK I can start final packaging in envelopes and shipping...
Below is the final content of a package for one pair..
Just need to wait for a test build and if everything OK I can start final packaging in envelopes and shipping...
Below is the final content of a package for one pair..
Another update.
Fran has built a Beta sample using the surplus components from this GB.
It essentially functions as intended, BUT the untrimmed DC offset is higher than expected.
I want to be 100% sure that what we send you works faultlessly.
So we are building a 2nd Beta sample to see if the same occurs.
The 1st sample has also been sent to be for analysis.
But I have urgent matters to deal with and shall not be able to sttend to this in the next 3 weeks.
So in the meantime, please be patient and bear with us.
Good things are worth waiting for.
Thank you for your patience,
Patrick
Fran has built a Beta sample using the surplus components from this GB.
It essentially functions as intended, BUT the untrimmed DC offset is higher than expected.
I want to be 100% sure that what we send you works faultlessly.
So we are building a 2nd Beta sample to see if the same occurs.
The 1st sample has also been sent to be for analysis.
But I have urgent matters to deal with and shall not be able to sttend to this in the next 3 weeks.
So in the meantime, please be patient and bear with us.
Good things are worth waiting for.
Thank you for your patience,
Patrick
No problem from this end!! You guys have a life too besides this stuff, just as a query has a final price for 1 set boards with matched set been determined? Thanks for time and effort.
best regards,
Steve
best regards,
Steve
With the help of Ripster and Fran, we built a second Beta proto and managed to locate the problem.
The original opamp IC used in previous prototypes were out of stock world wide.
So we picked an alternative that was supposed to satisfy all the requirements.
But it did not, and we tried 3 examples of the same opamp already, each having a different behaviour.
So there is no choice but to go back to the previous proven part.
We shall try to source one or two examples, just to make 100% sure they would cure the problem first.
Then we'll have to wait till this part is back at Mouser end of March, to purchase 40x for the GB.
Ripster has then to work out whether he can absorb the extra cost or not, as it is no fault of his.
The world wide chip shortage is making things very difficult, constantly having to make changes / compromises to component choice.
If someone is in Czech Republic or Slovakia and is willing to help, please contact Fran via DIYA.
We can then probably get those parts earlier.
Again sorry for the delay. It has proven to be a great decision to Beta test first.
Else we would have sent you this "wrong" opamp, and we'd then have 20 people having problems wit their build.
Patrick
The original opamp IC used in previous prototypes were out of stock world wide.
So we picked an alternative that was supposed to satisfy all the requirements.
But it did not, and we tried 3 examples of the same opamp already, each having a different behaviour.
So there is no choice but to go back to the previous proven part.
We shall try to source one or two examples, just to make 100% sure they would cure the problem first.
Then we'll have to wait till this part is back at Mouser end of March, to purchase 40x for the GB.
Ripster has then to work out whether he can absorb the extra cost or not, as it is no fault of his.
The world wide chip shortage is making things very difficult, constantly having to make changes / compromises to component choice.
If someone is in Czech Republic or Slovakia and is willing to help, please contact Fran via DIYA.
We can then probably get those parts earlier.
Again sorry for the delay. It has proven to be a great decision to Beta test first.
Else we would have sent you this "wrong" opamp, and we'd then have 20 people having problems wit their build.
Patrick
Another update :
We could not find ONE unit of the opamp we are going to use for the Beta test verification.
So we'll have to wait for Mouser (prediction 27 March).
Only when we test OK would we go ahead to purchase 40 units, before shipping to you.
So shipment likely to be some time in April.
Patrick
We could not find ONE unit of the opamp we are going to use for the Beta test verification.
So we'll have to wait for Mouser (prediction 27 March).
Only when we test OK would we go ahead to purchase 40 units, before shipping to you.
So shipment likely to be some time in April.
Patrick
Another update, and not on 1st April.
After the opamps are back in stock, Fran ordered some and replace the one on his 2nd Beta proto.
The IV converter still did not function as intended.
He sent me his first Beta proto earlier and I also swapped the opamp with the same outcome.
After 4 hours of debugging by stripping off components section by section, the defect was finally located.
The P-MOSFET was leaking current through the gate, which causes not only a large DC offset, but also the opamp to fail.
The most likely cost is electrostatic charges damaging the gate during handle.
This is now repaired, and the proto has been functioning for hours as intended.
The problem is of course that we do not know if further ones might be damaged.
We therefore only want to send out these 40 IV's as fully built and tested.
Fran and I would each build 20 units (thousand thanks to Fran).
And Ripster will help by soldering part of the components for all units before sending them to us.
Fran will also order new opamps and some spare MOSFETs.
We want to change the opamps back to the one we used in the original protos, to be 100% safe.
I hope the subscribers would be kind enough to reimburse him for these costs (most likely 6~8€ per subscriber).
Once all units are finished, Fran will send them off all in one go.
This will take some time, unfortunately, as it takes more than an hour to build one, if all goes well.
But it saves you building and testing time, so you get them ready to plug and play.
DC offset will be trimmed to regulated power supplies at exactly +/-15V.
The PSU voltage used for testing is measured and trimmed by 0.2% accurate multimeter.
We'll provide procedure later for DC trimming, should that be necessary
We shall only do this once.
Whenever we might offer this again, they will only be offered as finished units.
But at extra charges for build & test.
I hope there will be no objections.
You may alternatively ask for a refund, if it is not agreeable to you.
I am sure there will be takers.
This costs quite a bit less then the component costs of the through whole version alone.
Apologies for yet more delay.
Not that we want this to happen.
Patrick
(PS MOSFETs, whether SMD or through-hole, are all susceptible to gate damage by electrostatic charges.)
After the opamps are back in stock, Fran ordered some and replace the one on his 2nd Beta proto.
The IV converter still did not function as intended.
He sent me his first Beta proto earlier and I also swapped the opamp with the same outcome.
After 4 hours of debugging by stripping off components section by section, the defect was finally located.
The P-MOSFET was leaking current through the gate, which causes not only a large DC offset, but also the opamp to fail.
The most likely cost is electrostatic charges damaging the gate during handle.
This is now repaired, and the proto has been functioning for hours as intended.
The problem is of course that we do not know if further ones might be damaged.
We therefore only want to send out these 40 IV's as fully built and tested.
Fran and I would each build 20 units (thousand thanks to Fran).
And Ripster will help by soldering part of the components for all units before sending them to us.
Fran will also order new opamps and some spare MOSFETs.
We want to change the opamps back to the one we used in the original protos, to be 100% safe.
I hope the subscribers would be kind enough to reimburse him for these costs (most likely 6~8€ per subscriber).
Once all units are finished, Fran will send them off all in one go.
This will take some time, unfortunately, as it takes more than an hour to build one, if all goes well.
But it saves you building and testing time, so you get them ready to plug and play.
DC offset will be trimmed to regulated power supplies at exactly +/-15V.
The PSU voltage used for testing is measured and trimmed by 0.2% accurate multimeter.
We'll provide procedure later for DC trimming, should that be necessary
We shall only do this once.
Whenever we might offer this again, they will only be offered as finished units.
But at extra charges for build & test.
I hope there will be no objections.
You may alternatively ask for a refund, if it is not agreeable to you.
I am sure there will be takers.
This costs quite a bit less then the component costs of the through whole version alone.
Apologies for yet more delay.
Not that we want this to happen.
Patrick
(PS MOSFETs, whether SMD or through-hole, are all susceptible to gate damage by electrostatic charges.)
We shall only ask for payment once the task is completed, and we know what the final cost is.
Patrick
Patrick