How it works: the circuit as shown in FIG. VT1, VT2 and resistor R1 constitute a constant current source for charging the capacitor C2 for linear; VT3, VT4 and resistor R2 constitute a constant current source for
Click here to download the full size of the above Circuit.
discharging the capacitor C2 to achieve linear. Circuit is first turned on, the voltage on C2 is zero, 555 IC 2,6 feet less than 1 / 3Vcc, its 3 feet high output (approximately 10.8V), forward-biased diode VD4, VD3 reverse bias; VD1 positive partial, VD2 reverse bias. VT2 collector current charging C2 through VD1, when the voltage on C2 linear growth 2 / 3Vcc (ie 8V) when the 555 trigger 6 feet, 3 feet so that output low (approximately 0V). At this time VD1, VD4 reverse bias, and VD2, VD3 forward biased, the charge on the capacitor C2 through VT3 collector discharge, when the voltage on C2 linearly down to 1 / 3Vcc (ie 4V), the trigger 555 2 feet, leaving 3 pin reset output high, again and again, in 555 feet of 2,6 can get very high linearity of the triangular wave, and in 3 feet can get 50% duty cycle square wave. The frequency of this circuit is 0 ~ 200kHz and above range, and high stability. Frequency of the circuit by calculation:. F F0.1375 / (R1 + R2) C2 given by the circuit R1, R2 value, f F208kHz. Schematic VT5 high B output buffer stage, triangle pole removed from VT5 shot, by about 4V at the same time, the circuit can work application: change R1 or size R2, you can change the triangle wave rise or fall time, a corresponding change in the square wave duty cycle, or the control voltage 555 5 feet, 3 feet square wave can change the frequency (linear change).
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: