Cooling an instrument or a device can improve the SNR (signal-to-noise ratio), and it can also prolong product life. For example, the dark-and-noise signal of an infrared detector`s output at room temperature can be an order of magnitude smaller when cooled. We used the cooling device we built as part of a study of semiconductors. Figure 1 shows the block diagram of the system;
Click here to download the full size of the above Circuit.
Figure 2 ( view Figure 2 ) shows the circuit schematic. The design uses the temperature feedback signal to optimize the system. The heart of the design is an ATmega8535 microcontroller. It produces a PWM (pulse-width modulation) signal based on a temperature measurement. A thermistor-to-digital converter produces a digital output on its three-wire SPI (serial peripheral interface), sending the data to the microcontroller. A TLC7524 DAC (digital-to-analog converter) generates a control voltage from the PWM signal. The voltage controls the cooling device through an op amp and MOSFET (Q1), which can produce up to 2 A of control current. The Timer1 code reads the temperature data and computes an average value from 50 measurements. The Timer2 code compares the measured temperature to the temperature setting and adjusts the current to the cooling controller through the microcontroller`s PWM output signal.
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: