Frequency counter Input schematic

Posted on Feb 6, 2014

The master mode selection switch is IC6 which switches the 4 mode LEDs (which also correspond to the measured unity, i. e. kHz, counts, milli-seconds or seconds) as well as the input for the divider and the counter : For standard frequency counter mode (mode: 0, unity: kHz) as well as counter mode (mode: 1, unity: counts), the input A is used (for

Click here to download the full size of the above Circuit.

divider, etc); for both time measurement modes (mode: 2, 3; unity msec, seconds), the fixed 1MHz and 1kHz clock sources are used. This, of course, requires that there is another switch which acts as a gate to control exactly how long the output of the master mode switch is conntected to the divider and counter : This is IC9C, an AND gate whose enable input (pin10) is controlled by IC11: In counter and time measurement modes, this enable input is simply the AND (IC9A) of the measure signal from the logic board and the enable signal from the enable logic (left bottom in the sheet). For frequency counter mode, this enable logic has no use but here, the IC2A edge-triggered (D-type) flip-flop makes sure that the measurement actually starts at a HIGH-to-LOW transition of the input signal (this is the reason for the 2 inverters IC3A, B. When the measure signal from the logic board is LOW, the flip flop IC2A is reset (pin1) and hence provides similar functionality as the IC9A AND gate for the other modes. frequency counter mode, the In order to detect when measurement is finished, the "measuring done sensor" IC2B is used which triggers on the HIGH-to-LOW transition of the enable signal (IC11`s pin7). Especially note the "feedback loop" from pin9 to pin1 of IC11 which makes sure that once the measurement is finished (i. e. IC2B`s pin9 feeds HIGH into IC11`s pins 10, 12, 13), it is not re-started again before there was a reset pulse...

Visit page

Leave Comment

characters left:

Related Circuits

12V Battery Checker Circuit

This is a 12V battery checker circuit that uses 3 LEDs that light up at their respective voltages. The red LED lights up when the battery voltage is between 8 to 10V, the orange one at voltages...

230V Flasher Circuit diagram

This circuit operates with 230v. you can use this circuit to decorate your parties. I think this will be a wonderful circuit to you all. Here DIAC ER 900 and Triac BTW 11-400.

Automatic light activated switch circuit

The circuit can be used for switching OFF a particular lamp or group of lamps in response to the varying ambient light levels. The unit once built can be used for switching OFF a lamp when dawn...

BC548 Heat Sensor Diagram Circuit

Heat sensor circuit can be used to control any device using heat sensor. In this circuit a thermistor and a resistance is connected in series. This arrangement makes a potential divider circuit....

GSM CELL PHONE JAMMER SCHEMATIC

A wonderful diy gsm jammer or cellular mobile phone jammer schematic diagram for use only in GSM1900 with frequency from 1930 MHz to 1990 MHz. The GSM1900 cellular cell phone network is made use of...

Biosensor circuit

This week was spent completing a number of different objectives. Firstly, the software was downloaded to design the schematic for the circuit to be translated onto a PCB. Much of the week was spent...

Instrumentation circuit

The mechanical chassis prototype, as can be seen from the image on the left, was made using two materials: foam and aluminium. Foam was chosen due to its easy manipulation and aluminium due to its...

Hum Circuit

Although our kit utilizes an off-the-shelf microcontroller (AtMega328P-PU based Arduino), we additionally designed a simplified version. This allows other collaborators and students to potentially...

New Circuits

Zero consumption Anti-theft High power Code Switch for E-Bike Batteries

This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
Ultrasonic distance finder circuit

The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Simple Metal detector circuit with CD4030

Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Fully automatic watering circuit for flower pots

Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
Simple deep searching metal detector circuit

The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
Sub-Harmonic Bass Converter for Electric Guitars

The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
Echo Depth Sounding Sonar for Boats

In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
100W HiFi Audio Amplifier Circuit

This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
Plant-Pot Water Level Indicator Circuit

A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....

Create NOW your QR MENU for your Restaurant / Hotel / Bar / Caffe,

Comprehensive ordering/paying features. fully personalized to suit your Business.

Update Anytime! Easy and Simple!

Popular Circuits

12 Volt 20 Amp Solar Charge Controller

The SCC3 is a solar charge controller, it`s function is to regulate the power flowing from a...

Line Following Auto Robot

This Project Line Following Autonomous Robot is based on 8 bit Microcontroller AT89C2051. This...

55W (Originally 75W) Power Amplifier

To order boards, click to go to the ESP Purchase form. Verify the price and postage, then open...

COLLEGE QUIZ BUZZER

Manual buzzers used for quiz competitions in schools and colleges create a lot of confusion in...

fet current source

This is a constant current source using a FET. This is the most simple replacement to series...

Electronics Engineering Herald - online magazine of electronics -home

Embedded Systems is simply the brain of the most of the electronics based systems to access,...

h bridge driver circuit

The so-called regenerative effect of a 4-quadrant inverter. Yup you will need to dissipate that...

LEDs and resistors circuit

An LED is an electronic component or semiconductor to be more precise. This means that it is...

Low phase noise voltage controlled oscillator circuit

Low phase noise voltage controlled oscillator circuit a It shows a typical low phase noise...

AM circuit by MC1496

AM MC1496 analog multiplier integrated circuit configuration shown in Figure 21-39. Channel...