The decimal value of the eight input lines is displayed on three seven-segment displays. Although chips exist to perform this function for single displays, none include the possibility of displaying numbers greater than 9. No EPROM is necessary in this design. It operates by using two synchronized counters, one that generates an 8-bit binary outpu
Click here to download the full size of the above Circuit.
t, and a second that drives the display. If the display is updated only when the binary counter is at the same value as the input, then the display will show the decimal value of the input. IC4 is the binary counter, and IC6 to IC8 form the display/counter section. IC5a and IC5b form the astable, which clocks both counters at 5 kHz. The minimum display refresh rate is, therefore, 20 times per second, IC1 and IC2 are two 4-bit comparators, ganged to form an 8-bit comparator. This compares the output of the binary counter (IC4) with the binary input taken from the circuit under test. Resistors RI to R8 pull down the input lines to prevent them from floating when no input is connected. When the comparator inputs are equal, pin 6 of IC2 goes high, triggering the monostable (IC3ab), which outputs a brief pulse. This latches the value of the display counters (IC6 to IC8) to the display. When IC4 reaches avalue of 256, the link between pins 11 and 12 resets the chip, and this resets the display counter also. (View) Peltier-effect semi-conductor thermoelements maintain uniform cooling temperatures required for accurate specific gravity measurements. Null-position detecting circuit uses differential transformer to sense position of movable core at end of float. -C. W. Hargens, Semiconductors Cool and Control Density Gage, Electtonics, 31:49, p 80-8l. (View) Simple circuit uses Motorola MBS-4991 silicon bilateral switch to provide...
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....
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....
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....
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....
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....
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,....
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....
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....
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.....
characters left: