if you want to impress folks, or make a load, use a quad XOR (cd4030 or 4070 i guess). i own none of the ICs in question. but i have decades of dsp and can authoritatively state, you XOR those pulse waves together, you'll have one keen electronic percussion sound. the method is used for hihats in modular synthesis, but to my knowledge, no one has used it for anything else eg. snares. i have, in software (bong vst, acclaimed by many). add a resonant filter or such (and some highpassed white noise). the only problem then is that synthesis consumers don't like innovation, they like to do what they see famous people do. i'll leave this here for persons enjoying this channel.
There are two ongoing synth tutorials at the moment both using 40106 - Moritz Klein’s videos are GORGEOUS and well-explained, and Audio Phool is also doing really cool stuff (including synth cymbals most recently) on his channel. Highly recommend both.
The supply rail really needs a decoupling cap close to the IC. Adding two resistors, and two diodes to the feed back path allows the mark space ration to be set independently. The feedback resistor can be replaced with a pot to give an adjustable frequency output. Adding a transistor the feedback path allows the output frequency to be modulated. Schmitt's really are very versatile components, which I believe to be far more flexible than a 555 timer. For example, I recently used the quad Schmitt nAND to produce a stroboscope. This switches an LED array via a mosfet at between 1Hz to 38kHz, with a pulse output with, feedback control, between 150us at the slowest flash rate, down to sub 2us at the maximum flash rate, giving a good approximation of constant brightness. Adding a pic, provided a LCD flash rate readout, with a multitude pot providing analogue flash rate adjustment. In sound generation applications, the quad nAND, provides the option for one oscillator to be used to control another ( or more). While the output is a square wave the charge discharge curve of the input approximates to a triangle wave. Adding a transistor to the feedback path, configured as a constant current source, can produce a very linear ramp signal. RC filtering the square wave output can give a good approximation of a sine wave, all be it at a low amplitude. The Schmitt is really useful as button input denounce for other clock logic, such as state machines, counters, combination locks, alarm circuits, etc. A huge number of projects can be produced using this in combination with a Johnson ring counter.
This setup is actually the first step to make a simple TDR, Time Domain Reflector which is handy for measuring cable length and impedance. I've used the 74AC14 for it because of the extremely sharp edges of about 5ns
Great video Paul 👍 Thank you The only time I’ve had anything to do with a Schmitt Trigger is with a Hall Effect Sensor. Love learning about electronics 😊
always enjoy making pretty sounds - looking forward to this series very much! just wondering why the initial capacitor value gave a frequency that was not what we expected?
Good question. If I plug in Vn(min) = .9 and Vp(max) = 3.6 from the datasheet into the equation, the frequency works out to 79k. Not far from his scope reading.
@@Enigma758 I think 500Hz to 2.2 Hz is the recommended usable range. In other words the formula might not work quite so well outside of that range because of the chip characteristics. ETA: I'm also wondering if the duty cycle will get a bit closer to 50% with a higher resistor in the RC network.
@@Chris_the_Muso That occurred to me to. The 50k/100pf combo is pegged to the high end. However, even the slowest combination 51k/1uf is a bit off. Using Vp(avg) = 2.9 and Vn(avg) = 1.9, the formula yields 24hz compared to his 14hz.
@@Enigma758 Still with the 50K ohm resistor though - it would be interesting to see how accurate it is with component values more in the middle of the range. It's not that clear what is going on from the data sheet, but there's always a "gotcha!".
@@Chris_the_Muso I hear ya, it could be straddling that fine line. The chip could also be a low quality knockoff. Also, I usually test my resistors and capacitor before using them even if the markings appear correct, so that's one less thing that can go wrong. It might be a good idea to also check the Vd and Vn values with a voltage divider.
if you want to impress folks, or make a load, use a quad XOR (cd4030 or 4070 i guess). i own none of the ICs in question. but i have decades of dsp and can authoritatively state, you XOR those pulse waves together, you'll have one keen electronic percussion sound. the method is used for hihats in modular synthesis, but to my knowledge, no one has used it for anything else eg. snares. i have, in software (bong vst, acclaimed by many). add a resonant filter or such (and some highpassed white noise). the only problem then is that synthesis consumers don't like innovation, they like to do what they see famous people do. i'll leave this here for persons enjoying this channel.
There are two ongoing synth tutorials at the moment both using 40106 - Moritz Klein’s videos are GORGEOUS and well-explained, and Audio Phool is also doing really cool stuff (including synth cymbals most recently) on his channel. Highly recommend both.
The supply rail really needs a decoupling cap close to the IC. Adding two resistors, and two diodes to the feed back path allows the mark space ration to be set independently. The feedback resistor can be replaced with a pot to give an adjustable frequency output.
Adding a transistor the feedback path allows the output frequency to be modulated.
Schmitt's really are very versatile components, which I believe to be far more flexible than a 555 timer.
For example, I recently used the quad Schmitt nAND to produce a stroboscope. This switches an LED array via a mosfet at between 1Hz to 38kHz, with a pulse output with, feedback control, between 150us at the slowest flash rate, down to sub 2us at the maximum flash rate, giving a good approximation of constant brightness. Adding a pic, provided a LCD flash rate readout, with a multitude pot providing analogue flash rate adjustment.
In sound generation applications, the quad nAND, provides the option for one oscillator to be used to control another ( or more).
While the output is a square wave the charge discharge curve of the input approximates to a triangle wave. Adding a transistor to the feedback path, configured as a constant current source, can produce a very linear ramp signal.
RC filtering the square wave output can give a good approximation of a sine wave, all be it at a low amplitude.
The Schmitt is really useful as button input denounce for other clock logic, such as state machines, counters, combination locks, alarm circuits, etc. A huge number of projects can be produced using this in combination with a Johnson ring counter.
always nice seeing a new video from you!
Thanks Paul, in all my years of electronic hobby I never played with a Schmitt trigger inverter. I look forward to the rest of this series.
I'm really looking forward to next weeks video, I have had this chip lying around for a while now and you have rekindled my interest in it!
The Schmitt Trigger Inverter is a very cool chip. Looks like it has a lot of possibilities for stuff. Thanks for the video!
I think Schmitt Trigger circuits are especially useful in several applications
This setup is actually the first step to make a simple TDR, Time Domain Reflector which is handy for measuring cable length and impedance.
I've used the 74AC14 for it because of the extremely sharp edges of about 5ns
Thanks, Paul!
is it possible to control pulse width too with this arrangement?
Great video Paul 👍 Thank you
The only time I’ve had anything to do with a Schmitt Trigger is with a Hall Effect Sensor. Love learning about electronics 😊
always enjoy making pretty sounds - looking forward to this series very much!
just wondering why the initial capacitor value gave a frequency that was not what we expected?
Good question. If I plug in Vn(min) = .9 and Vp(max) = 3.6 from the datasheet into the equation, the frequency works out to 79k. Not far from his scope reading.
@@Enigma758 I think 500Hz to 2.2 Hz is the recommended usable range. In other words the formula might not work quite so well outside of that range because of the chip characteristics.
ETA: I'm also wondering if the duty cycle will get a bit closer to 50% with a higher resistor in the RC network.
@@Chris_the_Muso That occurred to me to. The 50k/100pf combo is pegged to the high end. However, even the slowest combination 51k/1uf is a bit off. Using Vp(avg) = 2.9 and Vn(avg) = 1.9, the formula yields 24hz compared to his 14hz.
@@Enigma758 Still with the 50K ohm resistor though - it would be interesting to see how accurate it is with component values more in the middle of the range. It's not that clear what is going on from the data sheet, but there's always a "gotcha!".
@@Chris_the_Muso I hear ya, it could be straddling that fine line. The chip could also be a low quality knockoff. Also, I usually test my resistors and capacitor before using them even if the markings appear correct, so that's one less thing that can go wrong. It might be a good idea to also check the Vd and Vn values with a voltage divider.
It seems we can make another inverter circuit 😊👍
So with this IC, you could send a sine wave to the input and the output will be a square wave?
Looking forward to part II.
Pretty much
Surely the LED and resistor changed things. Try running the output through another trigger to the LED
Nice. Ive been recently playing with a 555 timer and wonder how this chip is different.
I have been noticing an uptick in 4000 Logic chip use rather than the more common 74 TTL family. Wonder why?
The 4000 series has a wider voltage range. Synthesizers use this one volt an octave thing so they tend to run on 12V rails.
Awesome video dude thanks
they must a kind of latch inside which holds the output from jumping all over the place, YES??
Nice Video Paul.. : )
That's the hysteresis. It triggers on the rising edge at a higher voltage than on the falling edge.
One interesting thing is that the pulse seems longer high than low on the scope. Perhaps after inverting it is more easy to see.
The duty cycle is not 50% but for a simple clock pulse it should be fine.
good
I guess I should just order 30 of them from amazon.
It's a resealable ziplock bag why'd you rip it lol 😂
Hard on AND hard off?? 🤣