A typical Colpitts oscillator design. This circuit is very similar in operation to the Hartley oscillator described in Oscillators Module 2. 1 but the Colpitts LC tank circuit consists of a single inductor and two capacitors. The capacitors form in effect, a single `tapped` capacitor instead of the tapped inductor used in the Hartl
Click here to download the full size of the above Circuit.
ey. The values of the two capacitors (connected in series) are chosen so their total capacitance in series(CTOT), is given by: This gives the total capacitance necessary for the tank circuit to achieve parallel resonance at the required frequency. The frequency of oscillation is given by the same formula as for the Hartley oscillator: The individual values of C2 and C3 are chosen so that the ratio of the values produces the necessary proportion of feedback signal. However, the ratio of voltages across two capacitors in series is in inverse proportion to the ratio of the values, i. e. the smaller capacitor has the larger signal voltage across it. The main advantage of the Colpitts arrangement, is that the single inductor in the tuned circuit removes the effect of any mutual inductance between two coils where the alternating magnetic field built up around one inductor induces a current into the their inductor. This would affect the total inductance of the coils and so changes the resonant frequency of the tuned circuit. The circuit in Fig. 2. 3. 2 is the Colpitts equivalent of the Common Emitter Hartley Oscillator described in Oscillators Module 2. 1 (Fig. 2. 1. 4). It uses a common emitter amplifier, and as the tuned (tank) circuit tapping point in this configuration is connected to ground, the tank circuit produces anti-phase waves at top and bottom of L2, which ensures the correct phase relationships for positive feed back...
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: