4-digit counter module

This compact four-digit digital counter is suitable for any application, such as clocks, frequency meters, digital voltmeter, tachometers, stop-watches, scoreboards, etc. The counter module provides a reset switch and a carry output signal. The maximum count of the module depends on which version of the IC used: • the MM74C926 pulls its carry output high when[…]

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Frequency probe

The frequency probe enables ”listening in’ to the speed of a computer. It is, however, also suitable for use with other digital circuits because it makes high frequency audible so that signal can be conveniently monitored. A 12-bit counter serves as a frequency detector. The signal measured in a computer or digital circuit is divided by 1024[…]

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Special band-stop filter

Special band-stop filter: Double T filters are used in many 11 circuits. This type of filter can be made into a perfect band-stop filter, at least in theory. In the present circuit (Fig. 1), a double T filter is used in a different manner. It can have the characteristic of the combination of either a[…]

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Active bass correction

Active bass correction: Active loudspeakers offer the only way of obtaining good bass reproduction from inexpensive or small enclosures. The design described does not make use, therefore, of large, heavy enclosures to obtain a good result, but of acoustic feedback. A microphone placed close to the bass drive unit unfailingly registers every movement of the loudspeaker.[…]

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Pulse Shaper

The diagram shows that how the four gates contained in a 4077 may be used to build a circuit that doubles the frequency of a signal applied to it. In other words, it generates a pulse for every edge of the input signal; the pulse width is determined by the internal delay of gates IC-1a[…]

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Solid State

Solid State Voice Recorder

Integrated circuits ISD 1012, ISD 1016 and ISD 1020 from chip maker ISD enable sounds to be recorded and played back. The final two digits in type coding show the length of a sound message in seconds. The difference in recording and playback is caused by the sampling frequency. which is highest (10.6 kHz) for[…]

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