When speaking of fan control, there are generally 2 ways of doing it, linear control, and pulse-width control. The linear control is the most common. The idea is to decrease the voltage to the fan. If the fan is specified to 12 volts, in most cases you can lower the voltage to 6-7 volts. But if you want to go lower, the result is often that your f
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ans won`t even start. Another issue is step less regulation. This requires a variable resistor (rheostat) or a control circuit, using transistors. If you want to run a fan at 7 volts, the remaining 5 volts will have to be burned of as heat in the control circuit or rheostat. The linear control supplies the fan with a constant voltage. But the PWM control generates rapid 12 volt pulses, and the on and off timing determines the overall speed of the fans. Until now, the construction of a PWM circuit has been pretty tricky. It requires an advanced circuit to control the different time constants. But with CKControl II, all timing signals are controlled via the software, allowing us to utilize the PC parallel port as 8 individual, fully controllable PWM outputs. You can use the outputs for not only fans, but all kinds of things including Lazer LED`s, Cold Cathode lights as long as the maximum current output doesn`t exceed 0, 8 A for each channel. You could even add a relay and make the software turn your coffee machine on and off! How many fans can we add to the circuit, then That depends on the fans used. The electronic components used are specified to 1 Ampere per channel. With that in mind, we should stay below 0, 8 Ampere, or approx. 10 Watt per channel. A standard 80mm fan typically uses 0, 14 0, 18 mA (1 mA = 1/1000 Ampere). That makes 5 fans per channel a total of 40 fans for all 8 channels. But that`s a rather...
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....
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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....
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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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