This circuit uses small switching transistors. The maximum motor drive current is limited to about 250mA maximum at 5V. I`ve tested the circuit on voltages from 3V to 21V. With some component changes it should be usefulto 63V in a 36V PV panel system although I haven`t tried this yet. With higher voltage and the use of heat sinks on the bridge transistors much higher currents should be possible. (View)
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Circuit 1 tends to chatter the relays under certain lighting conditions as there is no built in hysteresis. This version uses a Schmitt trigger hex inverter circuit to eliminate the chatter. It works better but is more complex. Note! R4 and R5 are used to force parking when it gets dark. If parking is not desired don`t use R4 and R5. Parking may not be desired in low power consumption applications. Also, the parking resistors, R4 and R5, reduce sensitivity a bit. (View) I have been looking for truly low cost and yet accurate conventional solar trackers. The CdS tracker is pretty good but lacks accuracy and sensitivity. I was thinking about using PV cells as the sensor. I was experimenting with LEDs and noticed they generate voltage in sunlight. Bingo! This got me to thinking. They generate quite a bit of voltage. The green ones generate about 1. 65V, some as much a 1. 74V. Not the piddley. 55 volts of a silicon PV cell. How is this so Well, it turns out green LEDs are made from Gallium Phosphide, a semiconductor with a much higher bandgap voltage. I thought I had invented the use of LEDs as PV cells as I had never heard of this effect before. Well, after some investigating I found a number of references to this. The guys that had done the most work in this area were the people form the BEAM project. They make tiny solar powered robots and some used LED photo sensors. I had been using a very low threshold MOSFET in a TO-92...
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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