When the battery voltage is 11. 5V or less transistor Q1 is turned on and the LED D1 will be bright. When the battery voltage is between 11. 5 and 13. 5 V, the transistor Q2 is turned on and the LED D2 will light up. When the battery voltage is 13. 5V transistor Q3 will be on the D3 and the LED will light. The schematic diagram come fro
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m circuit: Car Battery Monitor with 3 LED power supply. Go to that page to read the explanation about above power supply related circuit diagram. Car Battery Monitor circuit This is a circuit diagram of the 3 LED bar graph type battery monitor ideal for monitoring the voltage level of the car battery voltage with battery. When the battery voltage is 11. 5V or less. Here is a simple battery monitor circuit in which the LED will continue flashing until battery voltage is above the level. Transistors Q1 and Q2 are wired as an astable multivibrator circuit. This flashing battery monitor circuit can operate from a variety of voltages from 6V to12V. The voltage level at which an LED stops flashing can be set by adjusting R4. When the a preset battery voltage reaches threshold flashing frequency decreases andwhen the voltage drops below the threshold of the diode D1 LED turns OFF. This is used to compensate for changes in voltage of the base emitter Q1 due the. This NiCd battery charger circuit is very simple but it has a current and voltage limiting. Lamp L1 will light brightly and the LED will be out when the nicd battery is low and being charged, but the LED will. The following figure shows a diagram of power fluorescent lights to a normal battery. It is very convenient when you can not use the grid. Principle of operation This scheme is a voltage converter for the type of blocking oscillator. . The following schematic is a...
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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