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.

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However that would require one extra chip for just one gate, whereas I had a spare flip-flop datashedt which could be ab used for the same job.

The length of supply lines is almost always more than two inches from the power supply to the breadboard. You could even remove the oscillator and just toggle RS manually or use a function generator. When the second decade reaches 6 the output datawheet IC10A will go low.

Datashheet, I think that if I have a 11MHz signal output on the pin 9, it should means that the oscillator is working This pulse is very short because its cause is removed by the reset almost instantly.

Solderless breadboards are further limited by their voltage and current ratings. Its signal level is constantly low, with only a very short rising pulse when the counter reaches 60 minutes.

Breadboards dataheet inductance to all the pins and force large loops in your wiring. The precision of the resistor value has no effect on the precision of the time base B. They also make proper power bypassing difficult because you have to use caps with long leads. And now the hours counter. IC2 forms hef datasheet time base oscillator and first pre-scaler stage.


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. This is a nice 0. Now IC9D will inverse the pulses hef datasheet from the push button.


Sign up using Email and Password. Sign up or log in Sign up using Google. On the next page I’ll explain the display circuit and power supply of the clock. We need 1Hz, not 2Hz, to hef4006 to our seconds counter. But this time the maximum count value is limited to Eventually the output of IC10C goes high when a button is pressed.

SB-Projects – Projects – CMOS Clock – Hardware

Otherwise the roll over of the minutes counter would advance the hours counter too. This is negligible for hf4060 frequencies, but if you are operating in the RF spectrum this quickly becomes problematic.

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OK, that’s enough for this one page. One significant factor that most people neglect is the series parasitic inductance on the supply line.


This reset pulse hef4600 very short, because once it is high, the counters are reset and the reset hef datasheet is gone again. But when the most significant digit of the hours counter increments the clock input of the flip-flop rises, datassheet sets the flip-flop, datasheer the Q output low. Email Required, but never shown. These kind of capacitors usually have a black line on top of their body.

Basically, the intrinsic capacitance of the breadboard may already be equivalent to the needed crystal load caps. It’ll give stiffness on ‘s supply lines and will give extra capacity to the to drive various parasitic capacitance on its outputs. This is generally why high frequency devices avoid breadboards.

However, it would make changing the crystal somewhat more involved. When the clock is switched to SET mode though, the SET line goes low, which keeps the reset line to the seconds counter constantly high, preventing the seconds counter to count.


Test at lower frequencies and see what happens. When the hours counter is reset, so is the flip-flop, making its Q output high. The Hours Counter And now the hours counter. The other sheet covers the display circuit and the power supply.

Another link from an Illinois ECE college course states:. IC2 also contains a 14 bit divider chain. 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. C5 is used to set the correct frequency.

I’ve added it again. It doesn’t really matter whether we use a rising or falling edge here because daatasheet carry pulse is very short. Axeman 3, 14 The 14 stage counter is receiving a signal from the oscillator stage as I can see it on the pin 9 but doesn’t count. PeterJ 16k 20 42 In my case datashewt pulse was about ns wide. I don’t need the output of the seconds counter itself, because I do not have a seconds display. And now the hours counter. This pulse datwsheet used to flash the colon between the hour digits and the minute datashret on the display.

I can see with hef0460 ‘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. TP1 is a test point at which you can measure the buffered