This circuit is easy to recognise by the three equal-value capacitors and two equal-value resistors connected to the base of the transistor. We have already mentioned the signal at the output of a transistor connected in COMMON EMITTER mode is FALLING when the signal at the input is RISING. This is called OUT OF PHASE signals and you cannot connec
Click here to download the full size of the above Circuit.
t the output directly to the input to get the transistor to oscillate. If you do, the rising output will be fed into the base to turn the transistor ON and this will reduce the output. The signal has to be delayed by a short period of time to allow the output voltage to rise and then the transistor can be turned ON to reduce the voltage on the output. This delay is created by a set of capacitors and resistors on the base. We have already mentioned the fact that a capacitor takes a period of time to charge and this feature is utilized in the PHASE-SHIFT OSCILLATOR circuit. The value of the components create a time-delay and this sets the frequency at which the circuit operates. But it`s a bit more complex than a single "time-delay" arrangement. Each capacitor is doing something different at each part of the cycle. The interesting point to note is the feedback signal only has to be about 1/50th of the collector signal for the circuit to operate as the gain of the transistor is about 50 to 100. This means there can be a lot of ATTENUATION (reduction) in the signal and the circuit will still operate. The signal through the 1M finds it difficult to pull the base up or down "quickly" because the 22n capacitor has a very large "holding effect" on the signal. This voltage is passed to the three uncharged capacitors and they pull the base up very quickly to turn the transistor ON. The secret to the operation of the circuit is the...
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: