Phasemeter for perfect coils

[dbanner]

Home made coils can be made to replicate precise factory coil parameters. Measure phase shift between Tx and Rx with this circuit. For example, tgsl DD -20 degrees. This circuit can measure the phase shift and results can be read off of a calibrated digital multimeter instead of an analog meter. But analog meter is very easy too because the scale is linear.
Now who has courage to draw layout and test. Both halves are the same, so draw single layout and copy for other half.

[dbanner]

Additionally, the phase shift of factory coils can be determined by using this circuit, instead of oscilloscope or in conjunction with oscilloscope, to verify results. The meter is calibrated linearly from 0 degrees to 360 degrees at full scale.

[Stariot svet]

Could be useful as o-scope replacement.
Additionally it can be build portable.
Worth to try.

[sinclairuser]

i wonder if we could tune this to make a meter circuit, it could be then used on pi detectors or vlf.
might be worth playing around with.
thanks you have been posting some very interesting circuits lately.

[rolling rock]

some necessary changes

Nice, useful project. But before somebody builds it, should point out that the LM311 will almost assuredly not work without:

a) pull-up resistor on the output. 10~20k should be good. The leading edge gets rounded with larger numbers, but this circuit's logic triggers on the comparators' trailing edge, so no worries... except above some unknown frequency.

b) LM311 must have the output "0" level output set by a connection on pin-1. Output will be referred to what it is seen on pin-1.

For instance, if you had a +5V and -5V supply (not needed here), connecting pin-1 to ground would give 0 to +5V. Or, for -5V to +5V connect pin-1 to -5V with pull-up going to +5V to get 10V output swing. Using a single +5V supply and grounding pin-1, makes for a 5V swing. The output is referred to pin-1 voltage so, ground pin-1.

Also, I would recommend trying the LP311 for longer battery life. At higher frequencies the calibration might not hold up, but
LP311 is going to use less power. If, with using LP311 your higher frequencies fail to calibrate like lower frequencies, use a smaller value pull-up resistor. Try that before switching to the much faster (more power hungry) LM311 (just a thought).
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You will have a lot of trouble finding an E300 anywhere. J300, where is it? 2N4392and 2N4393 JFETs seem to work well enough (in LTspice), but mine are only virtual tests; no bread-board at this time. There are lots of alternatives, but I've read 2N4392 specifically suggested as a possible replacement. There probably were not a ton of JFET options when this circuit was devised, there are now.

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Unless you use a voltage regulator, you might have varying full-scale output voltage as the battery ages. I'm running simulations in LTspice, and currently unable to change the logic voltage from +5V, so I can't be sure. Recommended: a low power 5V regulator, preferably a Low-Dropout Regulator (suggestions, anybody)?

[Stariot svet]

Thanks for your comprehensive input rolling rock.

Any other comments of experienced members?

[ivconic]

...

[Stariot svet]

...

Great!

Assume that this is PCB layout and schematic for this circuit?

What is best (free if possible) application to see and use it?

[ivconic]

Great!

Assume that this is PCB layout and schematic for this circuit?

What is best (free if possible) application to see and use it?

https://www.expresspcb.com/free-cad-software/

https://sprint-layout.software.informer.com/

[SWL]

I can not open the schema file .sch ... EAGLE 9.4.2 does not open. What software is needed?//// Opps! Sorry.... had seen

[rolling rock]

I figured out how to make CD4000 logic devices outputs in LTspice to follow changes in power supply voltage, and although this is an extreme example, it definitely shows how the phase meter's output will change for varying supply inputs. Here, the two input signals are at 180 degrees separation.

I had to enlist help from the Yahoo LTspice User's Group members to jog my brain. This is not a plug for Yahoo, but the LTspice user's group has a lot of smart people (kind of like it is here at Geotech1). That is where you would go to find the CD4000 devices, and other libraries, for adding to the LTspice collection that is otherwise pretty lame.

[dbanner]

Looking forward to the rise of
Skywalker.
Nuff said.

[Nandor]

It could be very useful!

[dbanner]

Thanks for all your contributions, and of course to very talented Ivca for layout.
Will be trying this circuit soon.

[boilcoil]

This is interesting schematic, but from past century.
Whay don't rearange it, make by chips only - simplier and easyer, like this:



I don't have model plate to experiment circle, and have not time to make real one, but there is not any reason chip-made scematic to work worse then the original.
Maybe it is necessary to adjust some resistors (or not), but it has to work.