I was used the standard cmos ic as cd4518 and cd4511 to built a 6 digits 60Mhz frequency counter, when I need to measure the higher frequency then it will through the 74hc390 pre-divider and set up sample time as 0.1 second.
Nice.After decades in a junk box it's time for the rebirth. Cut the end off an old USB A to B cable and solder the 5vdc wires to the board. Check the power input for shorts and plug it in to a USB port for power.
It seems to know that time as passed (2001, I'm sure I built it in the early 70's) but the time-base is not working correctly (no output).
Found and fixed a few loose solder connection and adjusted the crystal trimmer for the time base.
Crystal-controlled multivibrator with series-resonant crystal.
Bingo, we have the correct frequency from the quartz crystal.
That signal goes to the first divider stage of 3 7490 counters (2 in divide by 5 mode, 1 in divide by 10 mode )
for a 1khz output that feeds into another counter stage.
That looks good. The rest of the circuit has a 7400 for the gate functions with a 7474, 7490 and 7492.
Can't remember exactly how that worked so I'll have to trace that circuit later.
Why don't you post a schematic of your complete circuit instead of just a picture in your thread. If you don't have one, now is a very good time to start. You might even find the root of your problem.Nice.
My counter also uses a crystal Time base.
I start with a 1 MHz oscillator, a divider chain for my gate signals; transfer and reset.
I’ll post a photo of my protoboard project.
Where did you get your chips? I got mine in the 70's, long before counterfeiting from China became such a big problem.I tried using those chips.
Couldn’t get those to work.
We hear this so many times.Couldn’t get those to work.
I got mine from my distributor.Where did you get your chips? I got mine in the 70's, long before counterfeiting from China became such a big problem.
I breadboarded the circuit about 30 years ago and it worked fine. Instead of using 7 segment displays, I used HP 5082-7300 displays:
View attachment 199006
They cost about $20 per display if you can find them.
View attachment 199007
I study the datasheet before I purchase the chips.We hear this so many times.
A circuit may fail to work for 1, 2 , 3, ... so many reasons.
First issue is "circuit does not work" means nothing to us except perhaps DOA or "dead as a nail".
There are different states of "does not work" which when described properly can be helpful in diagnostics.
Half the time the reason for a circuit not working is because the chip is being used incorrectly and the user failing to read manufacturer's datasheet.
When a circuit does not function correctly it is important to analyze the behavior functionally. With debugging a complex system having an oscilloscope and a circuit diagram is almost mandatory.
That circuit appeared in an old Engineer's Notebook II sold and distributed by Radio Shack and written by Forrest M. Mims III first printing 1982 pages 34 & 35. There is a three digit, half the complete version, also. I actually used it along with a reflective photo cell (LDR) circuit involving V to F. When I used it it worked fine. The V to F was a FV9400 I think. That was a long, long time ago.
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by Luke James
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