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Originally posted by Alexmessomalex
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Post no.54 in this thread is the first. You should read thread and use search option before asking. -
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hi guys, so MJE5742 is not found in stores. ideas?Comment
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Use the DATA SHEET:Originally posted by Alexmessomalex View Post
https://www.onsemi.com/pub/Collateral/MJE5740-D.PDF
And parts seller's - DigiKey, Mouser, RS, etc parameter search feature to find a replacement.Comment
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Tim,
I've reviewed your Express PCB design and I saw that you have to update the emiter connection of Q1 to the + supply.
In te components placement it is correct
But not in the Express file
So component values in the schematic don't agree with the values in the PCB drawing
Regards
JoséComment
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That may be so Jose. I have not had the opportunity to check or etch this pcb. It was just a concept when I had limited success with the TL072 version a couple of years ago. I hope you have PCBExpress available to correct any mistakes should you choose to use this template.
All the best.Comment
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Tim,
Yes I am going to design a new PCB for a Pirat pinpointer. Although I think someone has done it before, I like to design my own PCBs. Yes, I will use Express, it is the SW I like more, and your design could be a good starting point, althoug I try to have a more slim PCB to adapt it in a pinpointer enclosure shape.
About component values, it looks like that those in the PCB are more coherent than the values in the schematic. But otherwise Eddy said he has used sucessfully these schematic values in the TL072 version. Perhaps he can provide us more information about this issue.
When I have ended my design I´ll try to provide the information.
King regards
JoséComment
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As starting point, here is the schematic drawn in Express PCB and translated to PDF
Any suggestions, errors, value comments?
Contributions are welcome, specially from those who have working the circuit sucessfully
Regards
José
Pirate_PI.pdfComment
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Here is the new schematic version with minor corrections, and the PCB design is finished.
PCB is 1" x 3,35". Here is also a Top cooper view and silk as advance of information.
I have two more projets on-going. These are a bit more complicated than RU-Pirat. When I finish both projets I will made the Pirat. When I test the working of the circuit I will provide the complete information. I don`t want to provide a PCB drawing with erros, I prefer test ir before.
In the mean time if there is any contribution to the proposed schematic it will be welcome
Regards
José
Pirate_PI_V2.pdf
Previa.pdfComment
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Looks very compact, for first testing the damping resistor can be replaced by a wire pot with 3-5w, 500RComment
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Hello Benrte-one,
Thank you for reply my post.
Yes I try to have a PCB as compact as I can, but still using through hole components. I have the coil connection in one side of the PCB and the powering in the other side. Sens. potenciometer connection near the laast side in order to use the circuit as a pinpointer.
I have seen in this thread that you have designed a compact PCB also. Have you had sucess with this circuit? Have you any recommendations?
Yes, I think the key for a secessfull in this circuit is the election of the correct dumping resistor. I wil try to get a pot wire as you said for known thw value I have to use difenetily, thank you.
Best regards
JoséComment
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I have a question for you guys, I bought a GP pointer AKA china knock off of the garret pinpointer, the detection depth is about two inch and if you use the coin slide trick that's going around youtube, it goes up to 4 inches, My question is are these pinpointer, Pulse induction ? can I tweak the damping resistor to get a permanent depth with it ? I already opened the sucker up, So if you guys need to see the board I can photograph it .Comment
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