Frequency Counter Control Circuit

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radioshack5209

Joined Nov 25, 2020
68
Hi:

I am building a frequency counter. I found a circuit that I modified slightly and that I hope will control
my frequency counter. I have breadboarded the circuit and probed the output with my scope. I have
attached a circuit diagram and the scope image. The negative output pulse should control the store
and the positive pulse should control the counter reset. Any suggestions?
 

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MrChips

Joined Oct 2, 2009
23,515
Hi:

I am building a frequency counter. I found a circuit that I modified slightly and that I hope will control
my frequency counter. I have breadboarded the circuit and probed the output with my scope. I have
attached a circuit diagram and the scope image. The negative output pulse should control the store
and the positive pulse should control the counter reset. Any suggestions?
We already covered this:
https://forum.allaboutcircuits.com/threads/gate-control-for-frequency-counter.174734/

Why are you starting all over again?
 

Thread Starter

radioshack5209

Joined Nov 25, 2020
68

Thread Starter

radioshack5209

Joined Nov 25, 2020
68

Reloadron

Joined Jan 15, 2015
5,934
Why was the circuit I provided no good at all? You should have posted back in the same thread. As to what I posted I built and used that circuit several times over and the original design was by Forrest M. Mimms and showed up in Archer's Engineers Notebook II. When you have a problem with anything you get here you should return to the original thread and post the problem rather than start a new thread. This is the original from the book. I suggest you review your circuit, explain why this circuit does not work because it is a pretty simple front end for a counter.

Counter Front End 1.jpg

Ron
 

Thread Starter

radioshack5209

Joined Nov 25, 2020
68
Why was the circuit I provided no good at all? You should have posted back in the same thread. As to what I posted I built and used that circuit several times over and the original design was by Forrest M. Mimms and showed up in Archer's Engineers Notebook II. When you have a problem with anything you get here you should return to the original thread and post the problem rather than start a new thread. This is the original from the book. I suggest you review your circuit, explain why this circuit does not work because it is a pretty simple front end for a counter.

View attachment 227106

Ron
Hi:

I built this circuit using a 74LS74 and a 74LS00. The wiring was 100%. I replaced the components twice. It just won't work.
And yes the circuit looks pretty straight forward. I have attached a schematic to show how I connected the 74LS74. Is
this correct?
 

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Reloadron

Joined Jan 15, 2015
5,934
If it was built exactly per that schematic and powered with 5 volts for the TTL logic it should work. Not much else can be said about it. It's a proven circuit. Guessing you don't have a scope to walk through it.

Ron
 

Thread Starter

radioshack5209

Joined Nov 25, 2020
68
If it was built exactly per that schematic and powered with 5 volts for the TTL logic it should work. Not much else can be said about it. It's a proven circuit. Guessing you don't have a scope to walk through it.

Ron
Yes I have a scope. I will have to rebuild the circuit and try it. I am wondering if my connections were correct. Please see the
attachment in post #7. Perhaps my translation from the 4013 to the 74LS74 was wrong. I am thinking about pins 1 and 4.
 

MrChips

Joined Oct 2, 2009
23,515
The circuit built with CD4000 series CMOS logic will not work with 74LS00 series logic unless you make some modifications to the resistor values.

Use the 74LS123 monostable multivibrator and you will not have any problems assuming that you do it correctly.
 

Thread Starter

radioshack5209

Joined Nov 25, 2020
68
The circuit built with CD4000 series CMOS logic will not work with 74LS00 series logic unless you make some modifications to the resistor values.

Use the 74LS123 monostable multivibrator and you will not have any problems assuming that you do it correctly.
Confusion. One person tells me to use circuit #1 and the other tells me to use circuit #2. I don't
think that the circuit using the 74LS123 is complete as yet. Neither will work as is.
 
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Thread Starter

radioshack5209

Joined Nov 25, 2020
68
You can use whichever circuit you choose. I have already given you both versions. You just have to do it correctly.
All you said was use a 74LS123.
If it was built exactly per that schematic and powered with 5 volts for the TTL logic it should work. Not much else can be said about it. It's a proven circuit. Guessing you don't have a scope to walk through it.

Ron
MrChips is saying the circuit won't work as is.
 
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Reloadron

Joined Jan 15, 2015
5,934
Mr chipps said if you sub TTL logic, as you did, for the CMOS logic in the circuit I posted you need to change the resistance values. He did not say the circuit I posted would not work. Can you even comprehend what Mr. Chips said? This is what happens when people learn to swim in the deep end of the pool. The circuit I posted will work just fine using the CMOS logic in the circuit. No, I did not think going from CMOS to TTL and using TTL voltage would necessitate changing resistor values so will deduct that error on my part from your bill.

If I had one circuit that would work I can figure out how and why it works later.
Back to the deep end of the pool. You have no clue how any of this actually works and want someone to give you a working circuit.

Ron
 

Thread Starter

radioshack5209

Joined Nov 25, 2020
68
There is no consistency: someone asking for a circuit, qualifying something "at all".

By the way, being all you get here, for free, no right to complaint about quality.
Some advice to you asshole:
1) This is none of you business.
2) When the experts give don't know what they are doing that is no help!
3) Learn to speak English.
4) Get back in the jungle.
 
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