Data sheet acquired from Harris Semiconductor. SCHSC − Revised October HCDB consists of an oscillator section and December CDBMS. CMOS 14 Stage Ripple-Carry Binary Counter/ Divider and Oscillator. DATASHEET. Pinout. Functional Diagram. HEF Datasheet, HEF PDF, HEF Data sheet, HEF manual, HEF pdf, HEF, datenblatt, Electronics HEF, alldatasheet, free.

Author: Akinogar Tygojinn
Country: Belize
Language: English (Spanish)
Genre: Spiritual
Published (Last): 1 July 2017
Pages: 258
PDF File Size: 20.53 Mb
ePub File Size: 5.70 Mb
ISBN: 800-6-55758-304-8
Downloads: 97752
Price: Free* [*Free Regsitration Required]
Uploader: Akinolrajas

BPete This could be a problem with the original 16MHz crystal Unfortunately I don’t have the datasheetbut the 11MHz one that I used, with 22pF capacitors, is the uef4060 that I used in dozens of other circuits, without problems.

Like I said in hev4060 comment before, you may need to start looking for the improbable, or things that you take for granted because they usually don’t fail: Axeman Hwf4060 happy you got it working!

The other sheet covers the display circuit and the power supply. The Time Base IC2 forms the time base oscillator and first pre-scaler stage. The problem could be related to testing at near the device’s maximum frequency on a breadboard.

This not only prevents the clock hdf advancing every minute during SET mode, it also starts counting a whole new minute once the hef datasheet is set to RUN mode again. When the hours counter is reset, so is the flip-flop, making its Q output high.

Both buttons have a debouncing capacitor in parallel to make sure that every button press results in just one pulse. Maybe this should be another question IC4B tries to do the same for the 0. My way of keeping this site alive.

SB-Projects – Projects – CMOS Clock – Hardware

Another link from an Illinois ECE college course states:. This is a nice 0. That means a huge parasitic series inductance for 16MHz. They also make proper daasheet bypassing difficult because you have to use caps with long leads. This reset pulse is also used as carry to the hours counter. When the second decade reaches 6 the output of IC10A will go low.


This reset pulse is very short, because datahseet it is high, the counters are reset and the reset pulse is gone again. Solderless breadboards are further limited by their voltage and current ratings.

The oscillator part is built as described in hef460 HEF data sheet. Please consider clicking on the Support Me button to show your appreciation. Test at lower frequencies and see what happens. Uef4060 have to tell the clock what time it is when it has lost all its power nef4060. Its signal level is constantly low, with only a very short rising pulse when the counter reaches 60 minutes.

You can download the circuit diagram here. This pulse is very short because its cause is removed by the reset almost instantly. Pins are almost always zero. TP1 is a test point at hef datasheet you hef datasheet measure the buffered hef datasheet While the clock is in run mode SET is high, opening the gate for the carry pulse.

We are only interested in two others, the Hz and the 64Hz outputs, which are used in the display section of the clock. The Q output will be used by the display part of the circuit to suppress the leading 0 of the hours counter.


The CLK input to the flip-flop is low, because the hours counter has just been reset to 0. But I think that this could be a problem caused by the breadboard as apalopohapa said.


In SET mode the SET signal is high, and the seconds to minutes carry can never occur because the seconds counter is held in reset. But when the most significant digit of the hours counter increments the clock input of the flip-flop rises, which sets the flip-flop, making hef060 Q output low. Otherwise the roll over of the minutes counter would advance datashfet hours counter datashert.

I don’t need the output of the seconds counter itself, because I do not have a seconds display.

It’s output Hev4060 of the first decade counter IC4A. The Wikipedia Page on them states pF per contact pointso you may have far dtasheet much capacitance on your crystal This pulse is used to flash the colon between the hour digits and the minute digits on the display. Eventually the output of IC10C goes high when a button is pressed. The Hardware Part 1 You can download the circuit diagram here.

oscillator – HEFB counter doesn’t count – Electrical Engineering Stack Exchange

So, the logic and Master Reset is working, but the counter is not. It also produces several other division ratios.

At the end dattasheet will produce an accurate frequency of 2Hz on output pin 3. I can see with the ‘scope that I have a nice 11Mhz sinusoidal waveform on the pin 11, and I see a not-so-nice square-ish waveform on the pin 9 so, I imagine that oscillator parts works fine. Now IC9D will inverse the pulses hef datasheet from the push button. What is IC3B doing there?

Back to Top