Free Simple Circuit Diagram
A pH meter circuit is basically an amplifier to boost a voltage signal which is produced by a pH probe. The pH probe itself is equal to a battery cell when submersed in the measured solution, producing a weak voltage and current signal. High input impedance requirement for pH probe while keeping the cost low, a 3130 CMOS op-amp give […]
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Stroboscope is used to measure the speed of rotation, using the effect of strobed light, where a moving object will be perceived as stationary object if the light is strobed fast enough relative to the movement speed. When applied to a rotating object, a mark on the object will be perceived as not rotating if the frequency of the strobed […]
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The following circuit shown in the schematic diagram converts temperature reading (from +30° to +30° F) to its corresponding frequency (30 to 3000 Hz). Other benefit is that a 4N28 isolate the output to protect the receiver from dangerous interference. We can use this circuit diagram to send temperature information across long transmissions lines because the 4N28 output voltage can […]
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The circuit shown in the following schematic diagram is a simple spectrum analyzer adapter circuit for oscilloscopes. This circuit can be used for scanning or monitoring a segment of radio spectrum or amateur band. Inside this circuit, an NE602 mixer chip generates a 455-kHz IF signal. The U2 is used to amplify the signal. Then the amplified signal is fed […]
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