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Meter Counter Circuits
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Frequency Meter Circuits
2.5GHz Frequency Counter
Digital frequency meter circuit diagram composed of ICL7107
Frequency counter 400Hz to 50MHz with PIC 16F84
It consists only from Microchip PIC 16F84 cpu and LCD text module. Author states that this counter is capable metering frequencies from 400Hz to 50MHz. I used faster, 20MHz version of 16F84A-20I/P, and it managed to count 80MHz oscillator output.
Frequency meter with 10Hz to 2MHz
7208 seven metric system counter is used for frequency meter, it has latch and multiplexing function, and contains direct drive circuit and display driver circuit. 7207IC is divided the output frequencyof6. 5536 MHz crystal oscillator by2 12which produces the 1600Hz square wave for calculator and display connection multiplexing. After fractional fr
Digital frequency meter course design circuit
555 ASTABLE_FREQUENCY METER
The circuit shown is a simple digital frequency meter, which indicates the frequency in hertz of an astable 555 timer. It could, perhaps, be adapted for other uses. An NPN transistor, TR2, is connected to the 555 astable to be measured, as shown in the in-set, and the output signal obtained is hooked to the main circuit via transistor TR1...
ANALOG FREQUENCY METER
This 1-kHz linear-scale analog frequency meter circuit uses the 555 as a pulse counter. Frequency is read on M1, (or 1 mA meter) which can be calibrated to read 0 to 1 kHz..
Analog frequency meter circuit
The circuit can measure the frequency between 1. 5kHz ~ 500kHz by connecting C1 ~ C6 different capacitors. The maximum frequency is up to 1MHz. Transistor T1 can be used as the integrator, and its load resistor is 15k © resistor and R1 ~~ R6 adjustable resistors. Integrator`s input signal is about 4 to 10V ( peak - peak value).
Digital Frequency MeterCircuit
Frequency Meter with 100 MHz RF desktop channel
10H2 to 2MH2 frequency counter circuit
The 7208 seven-stage decimal counter can be used as the frequency counter, it has the latch and multiplexing functions, and it has the direct digital driving circuit and the display driving circuit. 7207IC 6.5536MHZ crystal oscillator`s output frequency is divided by 2K to create the 1600HZ square wave for the multiple conversions of the...
This circuit shows an ICM7217 and an ICM7555 that are connected as a basic frequency counter. The connections between the ICM7217 and a common-cathode LED display are shown in Fig. 12-18. The frequency counter is calibrated (against a known standard) using RA as a coarse control and RB as a fine control.Notice that the ICM7555 timer is connected...
Temperature Probe for Digital Multi Meter
This is a simple temperature measurement probe circuit. This circuit measures temperature either on a PC board or at the probe tip to which contains the..
Digital pH Meter Signal Conditioner with Pulse/Frequency Output
A signal conditioner for pH meter probe is required to have high input impedance. The signal conditioning of the pH meter probe is done by providing a buffer..
Frequency Counter and Timer
In counter mode it provides 1Hz resolution up to 100Mhz. In timer mode maximum resolution is 0. 0000001 Hz up to 1Hz. Resolution is reduced by one digit for each additional decade. Multiple frequency updates per second by employing a sliding window for calculation. In case the AVR should be programmable in circuit, a few modifications must be...
Frequency counter BNC input schematic
This is a CMOS-compatible (and hopefully also TTL) input featuring over- and under-volatage protection. Schmitt triggers are used to allow for input with long transition times. Verified to work up to 30MHz.
Frequency counter Connection diagram
Frequency counter Counter schematic
The counter makes use of 5 cascaded CD40110 which combine a decade counter, a display latch and a 7 segment LED driver in a single chip. (The decimal points are driven by IC8x. ) The counter allows up and down counting (although only up counting is used in the frequency counter) and counts on the rising edge. An over- and underflow indicator is pro
Frequency counter Divider schematic
The divider design is pretty self-explanatory. One can choose between division by 1, 10 or 100 or no output (tied low) using the CONTROL input connected to the analog multiplexer HC4052. AC04are used to drive 3 indication LEDs as well as to buffer the signal. A single HC390 includes 2 divider by 2 and 5 which can be combined as 2 dividers by 10.
Frequency counter hardware keys schematic
This is basically 4 nearly identical debounced switches. The 2 resistors and one capacity at the input of each Schmitt trigger are used for debouncing the switches. The output is then fed into a D-type flip-flop which uses feedback to change the state (LOW to HIGH, HIGH to LOW) each time the button is pressed. Each key has a LED indicator, two wit
Frequency counter Input schematic
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
Frequency counter Logic schematic
The lower schematic is a pretty standard bidirectional rectifier together with capacitors and a 7805 as a fixed 5V source which supplies all the electronic in the frequency counter. For "security reasons" a fuse is used. The upper diagram shows the main microcontroller, an ATMega161, connected to all the other boards via various cables. JP9 (reset
Frequency counter Oscillator schematic
The oscillator provides a 1MHz and a 1khz clock. The 1MHz clock is used as the clock for the microcontroller and as timebase for millisecond measurement. I use a 2MHz and divide it by 2 in order to guarantee a 50% duty cycle. Then three halve HC390 are used as divider by 1000 which can be externally reset. This is necessary to make sure the millis
50 MHz frequency counter voltage meter & SWR/PWR indicator
This is a successor of the PIC16C71 4-digit LED f-counter & V-meter. Some hard to find parts used in the previous version, which are out of production for some time, has been omitted. A rather early PIC16C71 has also been replaced by 28-pin device PIC16F876. The later is capable of driving 4 digit LED display in multiplexed mode while measuring fr
Single Display LED Frequency Counter
As equipment becomes increasingly more compact, designers are often obliged to follow suit by reducing the size of displays. At some point, the usefulness of the display can become compromised. I, for one, dislike having to peer intently at tiny displays in an attempt to read vital information, if only because it serves as a reminder that my eyesi
I needed an excuse to use the soldering iron so I figured that I might as well as make a frequency counter which is something that I`ve always wanted, but lacked in my lab. Here`s the schematic. I drew it up in OrCAD PSpice a while back. Since then, I have lost the design files, but fortunately, I kept a hard copy, complete with annotations of...
VU Meter Circuits
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 measured. There are three main categories of distance measurement methods in use: a) By...
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 find something potentially valuable, hidden a few centimeters below the soil. So many...
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 circuit comes as a solution to this problem. Depending on humidity of the pot at...
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 circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
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, such as filtering or distortion. Instead, a frequency division system produces outputs...
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 calibration of the rope. This arrangement still exists in some yachts. The big...
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 supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
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. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
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