Free electronic circuit design and schematic diagram
Remote sensor might cause a trouble if it’s a passive type, has very low power output, and should be connected with relatively long cables. By supplying a current or voltage source through its connection wire, it’s possible to make long enough wiring without suffering much noise/interference. The following schematic diagram show a circuit consist of LM10 to make a remote […]
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Normally, frequency multiplier or divider has only discrete ratio operation since it uses digital divider as the main process for division or multiplication. By first converting the incoming frequency into a proportional DC voltage, we can perform frequency scaling easily with no restriction of discrete ratio operation. Here is the block diagram the scheme: We can accomplished it by using […]
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If the sensor system need an active supply, we can use only a single pair of cable to carry both the power supply and the output signal. Not only simplify the wiring, converting analog voltage level to frequency modulated pulse improve the noise immunity as well. Here is the schematic diagram of the system: The diode is employed to prevent […]
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This is a frequency source system that is controlled by a digital (microprocessor/microcontroller) system. This circuit produces a square wave signal with adjustable frequencies. Here is the block diagram of digitally controlled frequency source system: This frequencies are controlled by microcontroller register, counter or thumb-wheel switches. This system can be used in many applications like numerically-controlled machine tools and computer-controlled […]
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Look at the schematic diagram of a circuit below, imagine if the capacitor C1 is not charged and the power is off. There will be no current flow and Q3 will be open. The Base of Q3 will be high and the Base of Q2 low. The circuit is in stable condition and nothing happening. Power will flow through the […]
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Programming old EPROM devices needs high voltage, and this is a circuit of high repetition rate Vpp programming supplies. This circuit is used for memory programming that need higher repetition rate. This circuit produces the Vpp continuously by the switching regulator that runs continuously. To preclude any possibility of inadvertent Vpp output, the switching regulator mus t be turned of […]
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Power dropout detection is often required by digital system driven from the AC line. A memory store command to be issued before DC power falls is allowed by fast AC line drop out detection. The circuit on figure below detects AC dropout by connecting an optoisolator across the power transformer’s rectified secondary. Normally, the LED is turned on by the […]
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