The circuit is a fairly easy design: It consists of the actual VCO (ICL8038 with supplement parts), the sine and triangle output stage (LT1210) and the CMOS-compatible output stage using the MOSFET driver chip ICL7667. The ICL8038 and all parts around on the lower half of the sheet make up the actual oscillator which is a modified design based on
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one of the application examples in Intersil `s data sheet. There is a large 6-stage switch (S1) to select the major frequency and a logarithmic potentiometer (R2) for minor frequency selection. I discourage implementing the oscillator as shown in the above sheet because most of the other potentiometers turned out to be without significant enough effect on the output wave form to jusify their application. Furthermore, duty cycle adjustment will not keep a 50% ratio over all frequencies. The CD4030 on the left top is used as CMOS-logic signal preconditioning feeding the MOSFET driver IC ICL7667 as output stage for the complementary square wave output. The application of the two XOR gates has the advantage that it can supply a sqare wave and its complement without time offset between them (because CMOS has balanced raise and fall times). Use a bypass capacitor near the ICL7667 device as it can draw quite strong currents and is capable of driving into 50Ohm up to at least 10V resulting in rise/fall times of 30ns. So, I`m now entirely satisfied with the digital output. The industry-standard LM741 in combination with R11 is used to adjust the sine/triangle offset level. (Hint: You should probably use something better here - especially more output current cannot hurt. ) Since this oscillator is single-supply, it comes handy that you can change the "zero level" of the wave output; you will normally adjust that to half of the supply...
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.....
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