Bipolar PI design

[eduardo1979]

Hello everyone.
First of all, I congratulate Carl on this great project.
I've tried to add some fuel to the fire, as there is always room for improvement in any project.
Now the preamplifier is two-stage, using the OPA1612AID, the audio VCO is made with the famous 4046, the demodulators have been modified, as they were a bit problematic, the microcontroller power supply is independent, because I've added another voltage regulator (U3) and so we manage to isolate the digital power supply from the analog power supply, I've also added a 10V voltage regulator (U5) for the power supply of the Mosfets and the 4053, I've improved the Threshold using the same absolute value amplification circuit used in TDI, etc, etc. I want your opinion and collaboration, so that together we can get a very powerful PI and also very sensitive to small nuggets of gold. I listen to your opinions.
Regards,
Eduardo.

[Detectorist#1]

Hi dbanner,
Please, draw your's idea how to use 4011 in this case.

[dbanner]

As what? As level translator?

for driving 4066? can it not be powered to provide +/-5V drive

[Carl-NC]

A cheap alternative to the 74HC4316 is the 4053 or HEF4053 . they have level translation - see pdf. I have used them in this mode

True, but the 4053 is a triple and we need 4 switches, so you would have to use 2 chips. IC1 has an unused switch but in my layout it's not very convenient.

[Riss]

A cheap alternative to the 74HC4316 is the 4053 or HEF4053 . they have level translation - see pdf. I have used them in this mode

[Carl-NC]

Yes, but you would need to use the PMOS devices to drive the coils. The AF108 coil should work.

[pechkata]

Hello Karl can we apply this scheme to this project...?
What would you suggest - how many coils...?
The AF 108 coil - can we use it...?

[pechkata]

Thank you GeoMax - you are great...
I drew it too - but you beat me to it...
Well done good job...
Schemes speak all languages…

[GeoMax]

Hi GeoMax,

Time-diagrams and schematics are OK. Just the value of the resistor R3 of common emitter connection have to be 47K, not 1K.

Hi Detectorist#1,

Thanks for checking it. I think 10k for R3 should be okay. I did not paid attention to the resistor value of R3. The 1k is actually a "default value" when I pick a resistor from the library. I updated the value of R3 now to 10 to 47k Ohms.

[Detectorist#1]

Hi GeoMax,

Time-diagrams and schematics are OK. Just the value of the resistor R3 of common emitter connection have to be 47K, not 1K.

[GeoMax]

Here are the two ways -- common-emitter & common-base -- side-by-side. You can see they are exactly the same circuit and work exactly the same way but the CE version inverts and the CB version does not. Eduardo, use the CB version.

Hi Carl / Detectorist#1

would this be now drawn correct?

[Detectorist#1]

As what? As level translator?

[dbanner]

not possible to use a 4011?

[eduardo1979]

Thank you very much for the clarification. It has become clear to me that in my case I have to use the common base configuration.

[Detectorist#1]

Hi pechkata,
Just see pictures in post #112 from Carl. This are the variants if you want inverting or non-inverting scheme.