Free electronic circuit design and schematic diagram
Closed Loop Motor Control Closed loop (servo) control is used to make a constant speed motor control. Constant speed means that the speed of the motor will be kept constant although the load is change, or even when the electric supply voltage is also changed. The circuit maintain the speed at a constant value by sensing the actual speed using […]
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Thermoelectric cooler (TEC) or Peltier cooler is becoming popular because of its robustness and maintenance free characteristic. Here is one example of a linear thermoelectric cooler (TEC) driver circuit. This driver is capable of delivering ±2A into a TEC. This circuit operates on a single +5V supply and drives the TEC in the most preferred “constant-current” mode. Here is the […]
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As the price of security camera going down, installing the camera in the shop, office, or even in home becomes economically feasible. Providing a dedicated monitor for every installed camera is not efficient, and your CRT monitor might suffer phosphor burn if it used to display static image from only one camera. To display 1, 2, 3, or 4 cameras […]
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High voltage current sensing/monitoring can be designed using LTC6101 op-amp. The following current sensing circuit is capable of measuring electrical current in 500 volts system. Here is the schematic diagram of the circuit: Two external Mosfets is added to hold off the voltage, allows the LTC6101 to be connected to a very high potentials and measure the current flow. The […]
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This current sensing circuit sense the current at the high side (between positive supply and load). This circuit take the benefit of the microampere supply current and Rail-to-Rail input of the LT1494 op-amp. Here is the schematic diagram of the circuit: Look at the op-amp, the inverting input is connected directly to the output, and this negative feedback will keep […]
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A phase control circuit can be used to control the power delivered to an AC load. The phase control circuit control the AC waveform, cutting the cycle to give full cycle, half cycle, zero cycle, or somewhere in between. You can say this circuit is similar to a dimmer circuit, but the switching is synchronized with the zero crossing of […]
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Controlling the speed of three phase ac motor is done by controlling the frequency of the power line supply, since the motor is synchronized with the line frequency. Three phase ac motor speed controller is actually nothing more than three phase sine wave power inverter with variable frequency. The three phase power inverter is a complex circuit, but fortunately there […]
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