Discuss Make a very simple test for me in the UK Electrical Forum area at ElectriciansForums.net
You can build them, but it is quite a few parts for a single stage and given the expected crystal frequency of 20MHz and your scope's limit of 200kHz, to see something approaching a square wave you need to show at least the 3rd harmonic, and ideally 5th, so you would want a final frequency of around 200kHz/5 = 40kHz.And the bright idea is to actually build a D flip-flop circuit. Or use a chip that may already have some ready flip-flop pins.
Most of your ICs are of the CD4000 series, they are only able to clock in to a MHz or so. You need to look at the 74HC series (or 74LS) to get 20MHz or more capabilities. Generally 74HC is easy to work with, some others are not so easy (restricted voltage range, or very fast switching so issues on breadboard use, etc)I have a small list of personal chips I can put down for you to look over, and if you spot any IC that will fit this task, then poke me. I already seen one CD4013 x1 dual D flip-flop but I have only 1 of it.
See if you find others.
That sort of a circuit only works well for a limited frequency range. A typical digital divider works from "DC" (clock stopped) up to the clock limit of the IC (tens of MHz input for the 74HC family).Hmmm... I find Frequency divider using 555 timer !!!
Simple frequency divider
Electronic circuits, projects and tutorials. PCB details, microcontroller projects, power supply, high frequency and audio circuits.www.circuitlib.com
Don't put yourself down, you contribute a lot on other matters!Way over my little ole head just a mere installation electrician.
Hello my friend and salutations from Romania. I believe you speak in name of everyone and some clarification might be in order from my part. Indeed my frequency counter is on the road. That is plan B that is going to happen. But until it arrives, in 2-3 months, I think I can PUSH this thing a little bit. You know? That's my goal here. And by pushing, I mean to make something that works, even if I have to make it from different parts or even circuits. For example, a circuit made from discrete components that will make a single D Flip-Flop stage in the 10 stages that I calculated.q12x : Good evening. I have been occupied today to be of any help(?) but can see that some very able folk have responded.
What is your project goal now please? You have bought a frequency counter which arrives soon. You have some quartz crystals which you want to confirm work and their resonant frequencies. Thus, it seems to me you still need a test rig to put these crystals into to make them oscillate. And you need a way of connecting the test rig to the frequency counter to measure their resonant frequencies. I am happy to help but need some clarification on what next - the test rig?
But before all that - what do you intend to do with these crystals?
Yes... I am new to this chips you are speaking here. I will start looking for them and probably even buy, if they are not expensive for 100pcs as I usually buy all my components. It is good that you tell me about them. Thank you.....
Most of your ICs are of the CD4000 series, they are only able to clock in to a MHz or so. You need to look at the 74HC series (or 74LS) to get 20MHz or more capabilities. Generally 74HC is easy to work with, some others are not so easy (restricted voltage range, or very fast switching so issues on breadboard use, etc)
The 74HC4060 is cheap, if getting one then buy at least 2 and check it is the DIP version, not surface mount package. It is finding a place that won't charge you a stupid amount of postage that is a challenge!
Those are usually intended as bus registers and not so easy to turn in to dividers, though they are fast enough. However, you can covert them in to ring counters with the addition of an inverter:q12: Good morning. Thank you for your nice email. Gathering dust in my shed I have some 74LS273 octal D type flip flop ics.
https://www.ti.com/lit/ds/symlink/sn54ls273-sp.pdf?ts=1652639946774&ref_url=https%3A%2F%2Fwww.google.com%2F
That is a kind offer of helpI will post you some as a gift. Please private message me your address or somewhere to post them to from where you can collect them.
The LS versions are OK with high frequency crystals with low impedance but are far harder to make work reliably than the CMOS types. You generally can't use the single-inverter mode for parallel resonance as you need quite a low feedback resistor to pull the LS style of device in to its linear amplification region, so typically they are best used in series resonance using two inverters.Each chip will divide by 2exp8.
https://www.electronics-tutorials.ws/counter/count_1.html
I will include some 74LS14 Schmitt triggered inverters chips so that you can input the 20 MHz sine wave and output from it a square wave to clock the 74LS273.
https://www.ti.com/lit/ds/symlink/sn74ls14.pdf?ts=1599590379543
You could use a circuit like this using two Schmitt triggered inverter gates as your test rig for the crystals which would in turn output square pulse to drive the frequency divider:
https://electronics.stackexchange.c...nverters-in-quartz-crystal-oscillator-circuit
I see that a later circuit uses 74HCU04 inverters. I will see if I have any. I know I have some 74LS04 ones.
https://www.infinite-electronic.kr/datasheet/54-74HCU04D.pdf
http://web.mit.edu/6.111/www/f2017/handouts/labs/74LS04.pdf
Typically the data sheets only show the 555 going up to 100kHz operation. They were typically seen doing audio and below speeds, with newer variants having additional dividers inside to allow very long time constants without crazy sized capacitors.I believe you are trying to tell me it will not work using discrete D flip-flops or the 555 version of it, because they will not be fast enough for the 20M (or more) speed. If this is the case, please be clear with me now, before I start doing anything ((stupid)ly hard and slow).
No. What I'm saying is that I already bought 10pcs of 74HC4060 because like mister PC1966 said, they run at a bigger frequency and probably are newer IC's.I do not have any 74HC4060 to send you. I have a selection of other logic ics though which you may find useful. I have kept them all 74 series.
Yes, I have a line of engagementCould you give me some idea of what you will constructing next?
Reply to Make a very simple test for me in the UK Electrical Forum area at ElectriciansForums.net
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