Bipolar PI design

[ivconic]

Algan... You are again my dearest brother!

[GeoMax]

Hi

you can get the PIC16F18426 chips on amazon.de as well...

[ivconic]

[algan]

If it's through tme.eu they are from Poland the delivery is expensive if it's just for one integral it's not worth it, but here in Bulgaria a local store orders and sells at double the price it comes in about 2 weeks, and if it's through Farnell the store is in England it's ordered from the https://store.comet.bg/CatalogueFarn...JpcHAiOiIyMCJ9 website there is some tax the order arrives in about 5-7 days

[algan]

Carl ,can you tell me what the consumption is for just the TX without the rest of the electronics? Thanks.

[ivconic]

Excellent! Comet is also present here in Serbia! Thanks Algan!



Are there any essential differences between these two chip models?

I just found the difference, it's the packaging that makes the difference.
The pictures are the same so it's confusing. Ok, the "mystery" is solved.





Kudos Carl, good decision to move ITMD3 to a more visible place!

[ivconic]

In an attempt to come up with the simplest but at the same time the most effective solution for replacing the 4053, I put together a very simple concept.
The funny thing is that in the "mind" it works very well but in the Proteus simulator it doesn't!??
Ha, ha, ha!
In the Proteus simulator, it only works when I turn Q3 and Q4 upside down so that their "sources" go to ground.

[ivconic]

Finally, this concept would look like this when included in the rest of the schematic (click to enlarge):
(D1 and D2 may not be needed (friend's suggestion). But it is good to provide a place on the pcb for them, just in case)

[ivconic]

I understand what the confusion is. And now (I hope) the Source and Drain of all transistors are facing correctly:

[ivconic]

To make things clearer here is the revised schematic (click to enlarge):

[ivconic]

Any comments? Any mistakes?

[Detectorist#1]

Hi Ivconic,

Max Uds on Q1 and Q2 is below 30V (12V supply + negative Ugs of IRF740). No need to use IRF9640 with max Uds=200V as upper transistors. 30V P-ch transistors haves many times lower RdsON and lower input, output and reverse transfer capacitances. Also the price is also reduced. AP9435GH (TO-252 case) and IRLML5203PbF (SOT-23 case) are suitable parts. IRF740A is a new version of IRF740, with more modern technology, with two times reduced output capacitance and many times reduced reverse capacitance (good for fast PI MD). IC7C have to be market as part of TL074 - not LM324, but this most probably is typing error.

[boilcoil]

According to the diagram, only signals in the Vee - mass range will pass through 4066, i.e. you will lose the mass - Vcc part. In order to use the full signal, you, maybe, have to remove the direct control of the 4066 from the microcontroller, and add elementary drivers for control signals from the PIC, to cover the range Vee - Vss .

[ivconic]

Hi Ivconic,

Max Uds on Q1 and Q2 is below 30V (12V supply + negative Ugs of IRF740). No need to use IRF9640 with max Uds=200V as upper transistors. 30V P-ch transistors haves many times lower RdsON and lower input, output and reverse transfer capacitances. Also the price is also reduced. AP9435GH (TO-252 case) and IRLML5203PbF (SOT-23 case) are suitable parts. IRF740A is a new version of IRF740, with more modern technology, with two times reduced output capacitance and many times reduced reverse capacitance (good for fast PI MD). IC7C have to be market as part of TL074 - not LM324, but this most probably is typing error.

I'm not sure if I read the same thing in Carl's book or on some forum, these days I browse a lot of similar things on the net and it's all mixed up in my head. But I think you're right.
P-channels can be replaced without problems.
As for the new IRF740A... that's very good information, I didn't know that!
As for IC7C; I just corrected that in the same post.
Because it is unnecessary to repeat the same things in several posts.
I know from previous experiences that some members get involved later in the topic and are then confused by the frequent repetition of schematics...
Thanks!

[ivconic]

According to the diagram, only signals in the Vee - mass range will pass through 4066, i.e. you will lose the mass - Vcc part. In order to use the full signal, you, maybe, have to remove the direct control of the 4066 from the microcontroller, and add elementary drivers for control signals from the PIC, to cover the range Vee - Vss .

The micro is powered from ground to the negative rail, which is perfectly fine.
About 4066 I'm not sure... Carl must be involved, after all he's the author, not me.
But today a friend who does not speak English gave me similar complaints via email.
This is no longer valid.
...
Thanks!