# Counter IC circuit needed to divide by 430khz to 1?

#### russwr

Joined Aug 29, 2017
66
I have been using counter IC CD4059A as setting divide by 1000. This was to run led as 1 flash per second. Now the new R + C circuit needs divide by 430khz :1 second , for same led flashing on the selected output. How can I do this, so as Frequency can be verified as working, by the steady flashing. VCC as 5v, or 6 volts with voltage regulator. Can LM 555 IC be configured as frequency counter use, or is there a better way to divide by N? (Maybe multiple stages, as dividing by Ns)

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#### crutschow

Joined Mar 14, 2008
34,719
I have been using counter IC CD4059A as setting divide by 1000. This was to run led as 1 flash per second. Now the new R + C circuit needs divide by 430khz :1 second , for same led flashing on the selected output. How can I do this,
Why not use two CD4059A's?.
For example the first one divides by 1000, dropping the frequency to 430Hz, feeding the second one that divides by 430, dropping the frequency to 1Hz.

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#### Papabravo

Joined Feb 24, 2006
21,264
The factors of 430,000 are:

$$430,000\;=\;43\cdot5^4\cdot2^4\;=43\cdot10^4$$

So, it looks like you will need four decade counters and a divide by 43. The divide by 43 might take a while to sus out.

#### michael8

Joined Jan 11, 2015
421
How close to 1 Hz does the result need to be? Are you just flashing leds or ?

divide by 2**17 and then by 3 is 430e3/(2**17)/3. -> 1.09354 Hz

divide by 2**15 and then by 13 is 430e3/(2**15)/13. -> 1.00942 Hz

#### russwr

Joined Aug 29, 2017
66
It seems that, if a NE555 timer IC is used as astable oscillator state, then another one connected in series as monostable with proper capacitors and resistors can output single pulse at 1/ second for flashing led , and be much less costly than other methods. This then verifies that the frequency is there working, since pin 2 is used as input from the oscillator, and without using a regular frequency counter unit. I already tried it at 1.5Khz, works fine. Another 3rd timer in between those two ,can be used for duty cycle on time control changes. The IC is stated to be used up to 500khz. The 556 IC contains (2) 555 timers. Ebay sells prebuilt small boards ready to adjust. (Quality separate IC part would be Texas Instruments , or other US source.)

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#### Michal Podmanický

Joined May 11, 2019
91
Feed the 24bit counter (need 19 bits only) with this 430kHz pulses, compare counter outputs with number 430 000 by using few ANDs (in binary) , once the compare is matched trig whatever you need and generate a counter reset.

The ANDs comparator can be done very simply by couple of diodes.

#### crutschow

Joined Mar 14, 2008
34,719
Do you need to monitor the frequency of the oscillator or just that it is oscillating at some frequency?

#### russwr

Joined Aug 29, 2017
66
Do you need to monitor the frequency of the oscillator or just that it is oscillating at some frequency?
The Khz oscillator is expected to be on. I don't want a speaker output. The flashing 1 second led verifies that the oscillator is actually working, without an expensive frequency readout meter. The IC CD4059AE is obsolete but can divide by 1000 directly - as a single part. I only have 4 units. It should really be changed to different low cost set up for frequency divider.--- The NE555 at monostable setting would repeat, and reset automatically, a 1 second on time pulse width for an led , with the input of Khz frequency. (Undecided)

#### AnalogKid

Joined Aug 1, 2013
11,160
The flashing 1 second led verifies that the oscillator is actually working,
Oscillating, and oscillating at the correct frequency, are two very different things. If you just want to know that the oscillator is on, but do not need to know that it is running at a specific frequency (or simply greater than some minimum value), that is a very different circuit.

For example, if you just want to know if the osc is running, then one 555 can do everything you want with one extra resistor and capacitor. At any osc frequency from 5 Hz to 2 megahertz, the LED will flash at a 1 Hz rate. Is this good enough?

ak

#### russwr

Joined Aug 29, 2017
66
Oscillating, and oscillating at the correct frequency, are two very different things. If you just want to know that the oscillator is on, but do not need to know that it is running at a specific frequency (or simply greater than some minimum value), that is a very different circuit.

For example, if you just want to know if the osc is running, then one 555 can do everything you want with one extra resistor and capacitor. At any osc frequency from 5 Hz to 2 megahertz, the LED will flash at a 1 Hz rate. Is this good enough?

ak
High accuracy not necessary, as frequency can vary slightly either direction so many htz. The lower cost monostable 555 will suffice as an "Indicator" with flashing led, as the input oscillator will be in an on condition, and a speaker bellowing at a low 1 Khtz in people's ears is not desired. A higher 430khz as inaudible, still needs to be verified as working. If the input pin 2 of monostable has no source, the output led of pin 3 of same IC stays off, and shows that the whole testing meter is not working, for it's original purpose.

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#### MisterBill2

Joined Jan 23, 2018
19,093
Really, to verify that the oscillator is running at about the right frequency you could use a CD4040 binary counter and drive a high brightness LEd straight off of the output.One IC and ONE LED and no extra parts at all.

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#### russwr

Joined Aug 29, 2017
66
Really, to verify that the oscillator is running at about the right frequency yoy could use a CD4040 binary counter and drive a high brightness LEd straight off of the output.One IC and ONE LED and no extra parts at all.
The IC CD4059A is not available to purchase , and it had pin for divide by 1000, for the use of only (1) IC. (not multiple IC'S with many many wires.)

#### Ian0

Joined Aug 7, 2020
10,085
Really, to verify that the oscillator is running at about the right frequency yoy could use a CD4040 binary counter and drive a high brightness LEd straight off of the output.One IC and ONE LED and no extra parts at all.
Make that a CD4521. A 4040 only has 12 stages, which would give a 105Hz output.

#### Papabravo

Joined Feb 24, 2006
21,264
The IC CD4059A is not available to purchase , and it had pin for divide by 1000, for the use of only (1) IC. (not multiple IC'S with many many wires.)
Looks like your only alternative to finding pure unobtainium, would be a low pin count uP or FPGA. There are many obsolete parts that now have to be implemented that way. You're not the first person to come up against this problem.

#### AnalogKid

Joined Aug 1, 2013
11,160
If you divide 430 kHz by 2^19, you get 0.8 Hz. This should be close enough to 1 Hz for oscillator verification. Two CD4040's in series can do this easily. Add one small-signal FET such as a 2N7000 to drive the LED.

One CD4521 will do the same thing. Where are you located?

ak

#### MisterBill2

Joined Jan 23, 2018
19,093
Make that a CD4521. A 4040 only has 12 stages, which would give a 105Hz output.
OK, I did not adequately consider that. Use a CD4020 14 stage counter. That will drop the flash rate to 26 Hz.
OR, feed the high frequency thru a capacitor and diode to light the LED, as only an AC signal will produce much DC output.

#### ronsimpson

Joined Oct 7, 2019
3,156
Five years ago, I designed something that had a very similar function. I used a PIC12F508 or something similar. It is an 8-pin microcomputer. I was getting them for under \$0.50. I managed to fit several different functions in that part. Like brown out reset/ power up reset/ not working reset. Then at the end I used the micro with a EEPROM inside and save the cost of that part.

#### russwr

Joined Aug 29, 2017
66
OK, I did not adequately consider that. Use a CD4020 14 stage counter. That will drop the flash rate to 26 Hz.
OR, feed the high frequency thru a capacitor and diode to light the LED, as only an AC signal will produce much DC output.
I forgot to add an in series capacitor to the input pin 2 terminal of the constantly resetting NE555 monostable IC. High oscillator frequency AC will pass through capacitor, but not allow DC through. If the oscillator quits , the possible DC left, would not cause restarting of the IC again, to light up an led on output. If frequency changed, the IC would still show as working, but at the wrong frequency. What is needed is the exact same divider IC CD4059AE which actually divides by 1000, and the output led would ONLY flash 1 per second if only the oscillator was at 1000 cycles!
The CD4059AE is now again available on Ebay , after a long time has gone by. The RF 430khz AC or as pulsing DC frequency is way harder to set up for reduction down to 1 cycle of flashing LED for verification.

I put that IC type frequency divider circuit on internet recently as it was for 20,000 cycles brought down to 20 cycles for operating an electromagnet coil for an old design that was called Hydrostar. Many people had requested in the past on how to do the wiring for the divider.

#### MisterBill2

Joined Jan 23, 2018
19,093
If the oscillator frequency being active and correct is that critical then I suggest finding a more stable and reliable circuit. Some circuits ARE much better than others.