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?

 

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?

 

We already covered this:
https://forum.allaboutcircuits.com/threads/gate-control-for-frequency-counter.174734/

Why are you starting all over again?

The circuit that was suggested by Ron was no good at all. This circuit showed up under "74LS123
Pulse Width and Delay". I have breadboarded this circuit and it works as far as what I have done but
as it is, it doesn't control the counter.

 

Using a 74LS123 is a viable solution that I gave another member whom I believe had hijacked your thread.

https://forum.allaboutcircuits.com/threads/resolve-circuit-conflict.174990/

https://forum.allaboutcircuits.com/threads/resolve-circuit-conflict-2.175079/

If you do not understand how to make this work then ask for more guidance and show us your current circuit.

 

Using a 74LS123 is a viable solution that I gave another member whom I believe had hijacked your thread.

https://forum.allaboutcircuits.com/threads/resolve-circuit-conflict.174990/

https://forum.allaboutcircuits.com/threads/resolve-circuit-conflict-2.175079/

If you do not understand how to make this work then ask for more guidance and show us your current circuit.

I need more guidance please. The schematic and probed result is attached in post #1.

 

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.



Ron

 

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?

 

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

 

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.

 

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.

 

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.

 

You can use whichever circuit you choose. I have already given you both versions. You just have to do it correctly.

 

You can use whichever circuit you choose. You just have to do it correctly.

If I had one circuit that would work I can figure out how and why it works later.

 

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.

 

You can use whichever circuit you choose. I have already given you both versions. You just have to do it correctly.

You can use whichever circuit you choose. I have already given you both versions. You just have to do it correctly.

The 74LS123 version is something that I found and it is not complete. Where is the circuit that you gave me?

 

You can use whichever circuit you choose. I have already given you both versions. You just have to do it correctly.

If I was given one correct circuit with the correct component values I would have a circuit that works!

 

The circuit that was suggested by Ron was no good at all.

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.

 

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

 

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.

 

This member has been banned for a second time.