This project combines several features in one compact unit. The fundamental driver consists of a NE 555 square wave generator. During development, consideration and a certain amount of experimentation was given to the construction of a square wave unit using discrete components. Investigation showed however that the geometry of the square wave pro
Click here to download the full size of the above Circuit.
duced was so poor that additional complexity would be needed in the form of a Schmitt trigger circuit. In order to keep the unit as simple as possible, and at the same time produce a usefully clean and symmetrical square wave which could have further applications, the discrete approach was abandoned. The final square wave generator using an NE555 IC has both a low component count and is simple to construct; it produces an excellent square wave, rich in harmonics (for signal tracing), and ample output to drive the capacitance bridge. The whole unit in its basic form can be constructed on a piece of PCB only three inches square. If a capacitance substitution box - which in itself also has further application - is added, to extend the range and convenience of the bridge, the entire unit occupies 3" x 6". The unit is powered by a 9 volt PP3 battery. The following instructions include the circuit, component list, comprehensive layout and connection diagrams, and photographs of the completed prototype (basic) unit. The circuit diagram is given in Fig. 1, and is of the project in its basic form, i. e. without the capacitor substitution box. The circuit of the capacitor substitution box is shown in Fig. 2. With the the values of resistors used, this circuit oscillates at about 1 kHz, producing a square wave of approximately equal mark / space ratio. Should it be necessary at a later date, the frequency may be altered between about...
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: