The temperature controller is an integrated intelligent temperature control instrument . It uses a fully digital integrated design, with programmable temperature curve or fixed-point constant temperature control, multiple PID adjustment, output power limit curve programming, manual / automatic switching, soft start, alarm Switch output, real-time data query, communication with computer and other functions. The digital display temperature instrument and ZK thyristor voltage regulator are combined into one, which integrates temperature measurement, adjustment and drive. Thyristor-like load.
The digital display meter must first convert the continuously changing analog quantity into the intermittently changing digital quantity (A / D conversion), and then up the counter (if the input signal is a digital quantity, directly up the counter), register, decoder, and finally It is displayed on the LED digital tube.
In fact, most of the digital display meters are based on voltmeters. A large number of physical quantities are converted into corresponding electrical signals after being transmitted by the sensors. The input part of the instrument processes these electrical signals into regular voltage signals. The main body of the display meter is just a voltmeter, the difference lies in the input conversion part.
With the continuous development of digital technology and microcomputer technology, digital display meters, new display and recording instruments with a single-chip microcomputer as the core are increasingly widely used in industrial automation and industrial control fields. The digital display meter is the same as the pointer meter, and is compatible with various sensors and transmitters to measure electricity, pressure, level, liquid level, flow rate, temperature, etc., and directly display the measured results in digital form.
A digital display meter should have three parts: A / D conversion, nonlinear compensation and scale conversion.
Scale transformation: There is often a certain proportional relationship between the measured value and the engineering value. The digital display meter should not display the input value, but the actual engineering value, so scale transformation is required. The display range of the general digital display meter can be set in full range.
Of course, although the principle and composition of the digital display meter are relatively simple, it is not easy to do well. Many factors will affect the quality of the meter, such as design ideas, processing details, and component selection.
A / D conversion: convert analog quantity to digital quantity, there is a special single chip.
Non-linear compensation: Most of the measured parameters and displayed values show a non-linear relationship. In order to eliminate non-linear errors, a non-linear compensation circuit must be added to the instrument. Commonly used methods are: analog non-linear compensation method, non-linear digital-to-analog conversion compensation method, digital non-linear compensation method, etc.