A variable resistor provides a voltage input to the PIC which is converted to a digital value using the onboard Analogue to Digital convertor, this in turn is used to set the PWM duty cycle. Since the PWM duty cycle is adjusted using a voltage signal input to the PIC it is possible to use an alternative analogue front-end instead of VR1 to provide this voltage input and therefore control of the duty cycle.
A push button cycles through three different PWM frequencies: 980Hz, 3.9Khz and 15.6Khz. The setting is saved to EEPROM so it always powers up using the last selected frequency and an LED indicates the current setting.
There is also a digital control input that allows the output driver to be turned off. The PIC12F683, IC1 has an internal hardware PWM peripheral that is used to generate the PWM signal. The duty cycle of the PWM signal is controlled by VR1 which via R1 p
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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