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For the P fet>
The original zvp4105 has: Breakdown voltage 50v(this is over kill), on resistance 10R, output C 15pf, input C 40pf and reverse transfer 6pf. http://www.diodes.com/datasheets/ZVP4105A.pdf
The tp0202k has: Breakdown voltage 30v, on resistance ~2.1R, output C 11pf, input C 31pf, and reverse transfer C 4pf.
Also it was a good idea to make the lt1057/integrator opamp a standard dual opamp pinout as there is not a lot of chioce for better components in that package. I would suggest using a opa2141 for that job http://www.farnell.com/datasheets/610858.pdf
The challenge fellow goetechers, find better parts than what I have suggested above, after all I am just a diesel mechanic
For the P fet>
The original zvp4105 has: Breakdown voltage 50v(this is over kill), on resistance 10R, output C 15pf, input C 40pf and reverse transfer 6pf. http://www.diodes.com/datasheets/ZVP4105A.pdf
The tp0202k has: Breakdown voltage 30v, on resistance ~2.1R, output C 11pf, input C 31pf, and reverse transfer C 4pf.
Also it was a good idea to make the lt1057/integrator opamp a standard dual opamp pinout as there is not a lot of chioce for better components in that package. I would suggest using a opa2141 for that job http://www.farnell.com/datasheets/610858.pdf
The challenge fellow goetechers, find better parts than what I have suggested above, after all I am just a diesel mechanic
Cheers Mick
Hi Mechanics
Good one!
LT1057 pinout is alredy changed on pcb and they match opa2141 checked !
I will include you'r updates!
Cheers
Detecto
Well my car is LPG and I fix that, but only when it breaks As for upgrade to LPG, it would be more of a downgrade I think! All of the cool electronics and auto electrical problems I get to play with in tractors makes for interesting work!
I was more just having a poke and pointing out that I am no EE, therefore somebody with a lot more experience should be able to find better parts than the ones I found in about 20 minutes using the parametric search on element 14.....
Why copy the SD2000 as the old design? The front end can be replaced with AD797 for similar performance. The constant running switch mode supply can be made synchronous to lower the noise getting into the receiver. There are plenty of old parts like that transistor array ic that can be turfed out and replaced with newer components. The complete cmos oscillator and timing block of ic,s can be changed to a simple pic micro. It is a very old design and is easy to transform into a high performance detector. implement auto ground balance, it is not hard to do.
Why copy the SD2000 as the old design? The front end can be replaced with AD797 for similar performance. The constant running switch mode supply can be made synchronous to lower the noise getting into the receiver. There are plenty of old parts like that transistor array ic that can be turfed out and replaced with newer components. The complete cmos oscillator and timing block of ic,s can be changed to a simple pic micro. It is a very old design and is easy to transform into a high performance detector. implement auto ground balance, it is not hard to do.
Hi woody
Everything that you said, i already consider in SD2000 V1.2, if you read all post you will find the same things.
SD2000 deserves to be made in original as it is.
SD2000 V1.2 will be much more complex cct,
Completely front end recieve will be taken from SD2200 etc etc
For microcontroller i get some of dsPIC33xxxx, and try to program talk functions, auto GB, disc, we will see yet, it all depends from my free time, it is summer
I will talk about V1.2 soon.
Detecto
Everything that you said, i already consider in SD2000 V1.2, if you read all post you will find the same things.
SD2000 deserves to be made in original as it is.
SD2000 V1.2 will be much more complex cct,
Completely front end recieve will be taken from SD2200 etc etc
For microcontroller i get some of dsPIC33xxxx, and try to program talk functions, auto GB, disc, we will see yet, it all depends from my free time, it is summer
I will talk about V1.2 soon.
Detecto
I think you have the right idea Detecto. Its a real trap to keep trying to update a design as your building it. There's always something that can be done better so if you don't call a halt to the design process as some point then the result is it never gets finished. Having said that V1.2 does sound pretty cool.... No! Stay strong! Maintain discipline! Finish V1!
PS: I was very jealous of you northern hemisphere boys as I scraped the ice of my windscreen yesterday morning.
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