Electronic-Nulled Loops

[dbanner]

Sorry, I meant normally open type. You have to push to close the switch I mean. That will turn on the transistor which drives the INC pin.

[dbanner]

Schematic

[Mario-j23]

Good job, nice and clean diagram. There is still no +5v connection to which pin of the 4051 system does this path go?

[Altra]

Should be pin 16 on the cd4051

[dbanner]

Wish I had all the component values, I would have built and tested the circuit.
The pull up resistor values throughout the circuit are pretty straightforward, and so too the diodes. But there are some critical values associated with other parts of the circuit. These can be worked out though, but will require some extra work.

[dbanner]

The schematic I put still needs some work, there are a few things which I'm not sure about. I have to look at the main board to see the white wire labeled as CK, I don't know what that is.

[dbanner]

The electronic potentiometer you put on your schematic triggers on the negative going leading edge(datasheet ). Those on the board have been erased. I don't have any experience with these devices. I imagine it will require the correct one for the job of this circuit.

[dbanner]

Good job, nice and clean diagram. There is still no +5v connection to which pin of the 4051 system does this path go?

This is a mystery. It can't be Vdd(16) because pin 16 is already connected on the bottom side to Vin.

[dbanner]

What does one do with the unused in/out pins of the cd4051? Should they be left floating! Or maybe in this circuit they are connected to +5V or ground. To avoid any interference or crosstalk.
this maybe a clue to where that track is going. Pins 1 and 5 appear to be unused.

[dbanner]

Good job, nice and clean diagram. There is still no +5v connection to which pin of the 4051 system does this path go?

The track you highlighted is connected to the center pin of the regulator which is ground. It then goes off under the 4051 chip to pins 5 and 1, which are unused.
so the unused in/out pins are grounded.
The track also goes off to other part of the circuit which now seems to make sense. I hope I'm right.

[Mario-j23]

Should be pin 16 on the cd4051

On pin 16 of cd4051 there is power supply from PCB nautilus +12v rail

[Mario-j23]

The schematic I put still needs some work, there are a few things which I'm not sure about. I have to look at the main board to see the white wire labeled as CK, I don't know what that is.

Unfortunately, I was unable to find where the CK cable is connected. Somewhere around LM393

[Altra]

On pin 16 of cd4051 there is power supply from PCB nautilus +12v rail

That's good to know. The 4051 has vdd (12v), vcc digital ground(?) and -vee or analog minus(B-)?

It's important we know the power connections for the digital pots.

[Altra]

What does one do with the unused in/out pins of the cd4051? Should they be left floating! Or maybe in this circuit they are connected to +5V or ground. To avoid any interference or crosstalk.
this maybe a clue to where that track is going. Pins 1 and 5 appear to be unused.

As a rule of thumb all inputs should be connected to vdd or vcc to prevent oscillation or latch up. The unused switch I/Os can be left floating.

[dbanner]

Few more things were missed. The electronic potentiometers are paralleled, both pin 3's are connected together as well as both pin 6's. I've updated my schematic. I think it's pretty much done. But it may be that there are still some unknown error somewhere.