new module free schematic

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EATyourGUITAR
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new module free schematic

Post by EATyourGUITAR » Tue Mar 24, 2020 1:39 am

I open sourced the schematic. I own this drawing but you can do anything you want with the concept. a module like this did not exist although you can patch it from other modules. you can replace the comparators with opamps if you are building through hole. maybe you can build this on strip board. enjoy.

Image

Image

P.S. if you want to double check I got the shut down pin right here is the datasheet. it was confusing me if active means the IC is active or the shutdown mode was active.
http://www.ti.com/lit/ds/symlink/tlv1805.pdf
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Re: new module free schematic

Post by jorg » Tue Mar 24, 2020 7:44 am

So each input acts as a clock to latch the other input, and is also available by itself. This looks like a handy utility for clock generation and processing. Hmmm, if -Q was available, the module could also act as a clock divider.

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Re: new module free schematic

Post by EATyourGUITAR » Tue Mar 24, 2020 8:00 am

jorg wrote:
Tue Mar 24, 2020 7:44 am
So each input acts as a clock to latch the other input, and is also available by itself. This looks like a handy utility for clock generation and processing. Hmmm, if -Q was available, the module could also act as a clock divider.
it is available. your two inputs per channel are inverting and non-inverting. if you take the Q OUT and put it back to the inverting input of the same channel it would be logically equivalent to taking the NOT Q and patching back to the non-inverting input. you may need to use s-trig instead if a regular gate/trigger. I haven't fully wrapped my head around that. I know that it is versatile so if you want the logic to trigger on rising or falling clock edge you can just swap the inputs around when patching. you may want to put the pot on the other input. it depends on your most frequent use case what your preferred default behavior would be.
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Re: new module free schematic

Post by BugBrand » Tue Mar 24, 2020 9:34 am

Not entirely sure - but is it wise using the LM4040s for the power lines for the 4013? Especially given the limited current through the 10k resistors.

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Re: new module free schematic

Post by EATyourGUITAR » Tue Mar 24, 2020 9:59 am

BugBrand wrote:
Tue Mar 24, 2020 9:34 am
Not entirely sure - but is it wise using the LM4040s for the power lines for the 4013? Especially given the limited current through the 10k resistors.
all the inputs are buffered by schmitt triggers so the 4013 only sees very fast rising or falling edge. the steady states are VDD and VSS. remember that CMOS only consumes power when the inputs or the outputs are in transition. they do not consume power when they are in steady state. the output is not connected to the jacks. it goes to a high impedance jfet or mos input depending on what you used for your analog comparator IC on the output buffer. even if it was a problem, it would only be at 20KHz and only if you didn't put reservoir caps on the +5v and -5v lines. I think you need to consume something like > 1.4mA continuously for > 1ms with 100nF. > 100ms with 10uF. eventually the 5v lines would go to zero and you would just be slamming logic signals larger than VDD through a 140K resistor. because I do not have any TLV1805 here I can not look at rise times to judge the power consumption. maybe I can pull that from the datasheet. a lot of this is very loose estimations on the back of a napkin. if I RC low pass all the inputs at 20KHz then there will be set operating limits that prevent undervolt overvolt failure mode of the 4013 from the 5v rails crashing. in theory it could be a problem but if we test it we can just set limits that make it robust. it could be that it is fine as is limited max Hz by the cable capacitance. feel free to make an official release by Tom Bugs. I would be honored to be in your museum even if I get nothing in return. I am a huge fan of your work. go for it.
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Re: new module free schematic

Post by devinw1 » Tue Mar 24, 2020 10:27 am

Looks cool. But, one question, why not just use a L78L05/7905 instead of the shunts since you are going ahead and powering the flip flop with it anyway? It would be the same package/footprint. Well, I guess with 2 added bypass caps.

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Re: new module free schematic

Post by jorg » Tue Mar 24, 2020 11:31 am

EATyourGUITAR wrote:
Tue Mar 24, 2020 8:00 am
if you take the Q OUT and put it back to the inverting input of the same channel it would be logically equivalent to taking the NOT Q and patching back to the non-inverting input.
Oh, right! :doh: Nice!!!

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Re: new module free schematic

Post by EATyourGUITAR » Tue Mar 24, 2020 11:33 am

devinw1 wrote:
Tue Mar 24, 2020 10:27 am
Looks cool. But, one question, why not just use a L78L05/7905 instead of the shunts since you are going ahead and powering the flip flop with it anyway? It would be the same package/footprint. Well, I guess with 2 added bypass caps.
I did it to save space as you can see from the PCB. I did not order the PCB yet so I can change it before I order it. or I can use a bigger zener. or a smaller resistor. if I can get a 7805 in SOT23 then I am probably going to do that.
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Re: new module free schematic

Post by devinw1 » Tue Mar 24, 2020 3:44 pm

EATyourGUITAR wrote:
Tue Mar 24, 2020 11:33 am
devinw1 wrote:
Tue Mar 24, 2020 10:27 am
Looks cool. But, one question, why not just use a L78L05/7905 instead of the shunts since you are going ahead and powering the flip flop with it anyway? It would be the same package/footprint. Well, I guess with 2 added bypass caps.
I did it to save space as you can see from the PCB. I did not order the PCB yet so I can change it before I order it. or I can use a bigger zener. or a smaller resistor. if I can get a 7805 in SOT23 then I am probably going to do that.
Cool cool. I would think if you don't need the precision that a shunt can offer, the linear regulator is probably easier. You can indeed go with a higher current for the shunt as well, but it will use more power of course and is still loading-dependent unless it's buffered somehow.

You can also take 1 shunt refernece and one dual op-amp and make +/-5V rails that are buffered.

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Re: new module free schematic

Post by EATyourGUITAR » Tue Mar 24, 2020 9:51 pm

devinw1 wrote:
Tue Mar 24, 2020 3:44 pm
You can also take 1 shunt refernece and one dual op-amp and make +/-5V rails that are buffered.
more pins. harder to place. opamps have 8 pins. I have done this before on the joystick module. it works well.

for this module I value space and price. the LM7805MP is the smallest I could find. about 8mm package. $1.31 each!

BZX84C5V1LT1G is $0.12 or $0.04 in quantity of 100+. it is 250mw 5.1v SOT23 (my favorite). use 330R pull-up for max load of 15mA per rail. problem solved. 80mw. heat no problem.
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Re: new module free schematic

Post by cackland » Tue Mar 24, 2020 11:41 pm

Very nice. Thanks for sharing. Whats the HP (looks like 6)?

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Re: new module free schematic

Post by EATyourGUITAR » Wed Mar 25, 2020 8:00 am

cackland wrote:
Tue Mar 24, 2020 11:41 pm
Very nice. Thanks for sharing. Whats the HP (looks like 6)?
4HP
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Re: new module free schematic

Post by guest » Wed Mar 25, 2020 8:33 am

looks good, and very useful. another possibility for powerintg the 4013 is to just run it off 0V/+12V, and then level shift the inputs with resistors.
openmusiclabs.com

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Re: new module free schematic

Post by BugBrand » Wed Mar 25, 2020 9:30 am

EATyourGUITAR wrote:
Tue Mar 24, 2020 9:59 am
BugBrand wrote:
Tue Mar 24, 2020 9:34 am
Not entirely sure - but is it wise using the LM4040s for the power lines for the 4013? Especially given the limited current through the 10k resistors.
all the inputs are buffered by schmitt triggers so the 4013 only sees very fast rising or falling edge. the steady states are VDD and VSS. remember that CMOS only consumes power when the inputs or the outputs are in transition. they do not consume power when they are in steady state. the output is not connected to the jacks. it goes to a high impedance jfet or mos input depending on what you used for your analog comparator IC on the output buffer. even if it was a problem, it would only be at 20KHz and only if you didn't put reservoir caps on the +5v and -5v lines. I think you need to consume something like > 1.4mA continuously for > 1ms with 100nF. > 100ms with 10uF. eventually the 5v lines would go to zero and you would just be slamming logic signals larger than VDD through a 140K resistor. because I do not have any TLV1805 here I can not look at rise times to judge the power consumption. maybe I can pull that from the datasheet. a lot of this is very loose estimations on the back of a napkin. if I RC low pass all the inputs at 20KHz then there will be set operating limits that prevent undervolt overvolt failure mode of the 4013 from the 5v rails crashing. in theory it could be a problem but if we test it we can just set limits that make it robust. it could be that it is fine as is limited max Hz by the cable capacitance. feel free to make an official release by Tom Bugs. I would be honored to be in your museum even if I get nothing in return. I am a huge fan of your work. go for it.
Thumbsup -- I'm probably overly cautious with such things, hence why I'd never thought to try LM4040s in such an implementation.

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Re: new module free schematic

Post by devinw1 » Wed Mar 25, 2020 10:09 am

EATyourGUITAR wrote:
Tue Mar 24, 2020 9:51 pm

BZX84C5V1LT1G is $0.12 or $0.04 in quantity of 100+. it is 250mw 5.1v SOT23 (my favorite). use 330R pull-up for max load of 15mA per rail. problem solved. 80mw. heat no problem.


:tu: Those are nice and they have the tight tolerance ones too.

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