Free electronic circuit design and schematic diagram
A modulated current is provided by the integrated rotational speed sensor KMI 15/x. This current signal must be converted to ground referenced voltage signal, matching the logic levels of the processing unit for digital signal processing. This signal conditioning can be done by using this circuit. This circuit consist of protective elements to suppress line conducted interference and low pass […]
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This is AC mode universal motor drive circuit. This circuit is suitable for large range of application. It uses the microcontroller to interpret the user interface that is used to select the four operating modes that are defined in hardware. Here is the circuit : As power switch, this circuit use “SNUBBERLESS” TRIAC BTA 12-600BW with a maximum specified gate […]
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This is a circuit of Temperature-Compensated Capacitive Proximity Detector. it will lights the LED when a person approaches the antenna plate. Here is the circuit : The 4-inch-square antenna plate and a 33pF capacitor (C1) in parallel with 15pF (6 inches of coaxial cable at 30pF per foot) are used to form delay capacitance of this circuit. It charges to […]
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This is a circuit of differential analog switch. This circuit uses the FM1208 monolithic dual. Here is the circuit: This circuit is ideal choice for an accurate multiplexer because RDS (on) for the monolithic dual tracks at better than ± 1% over wide temperature ranges (-25 to +125°) although it is unusual. [Source: National Semiconductor Application Note]
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This is a simple circuit that can be used to convert a low-voltage PWM signal into a buffered and amplified linear output. This circuit is designed for fan speed control. It uses PWM outputs to control fan speed as a function of temperature. Here is the circuit: As a linear amplifier, this circuit uses a PMOS FET (Q2) and a […]
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The large issue today that caused by more electronic equipment enters the home and the office is noise of fan. to reduce fan noise, a variable speed fan is used because it permits quieter and slower, fan speed when temperature conditions allow. To build a variable speed fan we can use digital control or high-speed/low-speed switches. Digitally controlled fans perform […]
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This is a circuit that transmits temperature data over an IR link and it allows the isolation of temperature sensor. It is a good solution of obtaining temperature readings from points at potentials a few tens of volts from ground by linking a temperature probe only by an IR connection to the readout point. This circuit consist of a temperature […]
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