Free electronic circuit design and schematic diagram
Field strength meter is a “must have” equipment if you’re dealing with radio transmitter electronics. Here is one example of this kind of circuit that works for 2.4 GHz band: An optional amplifier can be inserted after the rectification, so it can be used to boost small signal. This circuit works only for short distance transmitter since the signal must […]
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The strength of a radiated signal from a transmitter is measured by this circuit. It is commonly used by model airplane builders to check whether their transmitter are really transmitting the radio signal. One can quickly determine whether the problem lies on the transmitter or the receiver module using this FS meter. The only active element in this circuit is […]
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This is a Cable Reflection Tester circuit. This circuit can be used to check coax cable runs for shorts or even impedance mismatches. This circuit will send a pulse down the circuit, then the return signal can be checked on an oscilloscope. The distance can be determined by using this equation:distance = time x speed equations. Here is the schematic […]
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This circuit diagram shows us about simple SWR which is built using readily available parts. Take a note that to ensure accurate power reading, no attempt has been made . If we want a circuit that would fit in a small enclosure, and give an indication of minimum SWR, this circuit does the trick. The trick is based on the […]
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This is a decibel meter circuit. This circuit is used to measure sound pressure level (SPL) from about 60 to 70 dB. In this circuit, transistor stage and one LM324 op-amp section are used to amplify the sound that is picked up by an 8 ohm speaker. As voltage comparators, the circuit uses The remaining 3 sections of the LM324 […]
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ESR is Equivalent Series Resistance. ESR is one of the characteristics that defines the performance of an electrolytic capacitor. It’s highly desirable to use Low ESR in capacitor as any ripple current through the capacitor causes the capacitor to heat up due to the resistive loses. By drying out the electrolyte at an ever increasing rate, the heating accelerates the […]
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The ESR (Equivalent Series Resistance) of an electrolytic capacitor is normally just a low voltage capacitor (such as a 1000uF, 16V cap), small fraction of an Ohm for a high capacitance, and can be as high as two or three Ohm for a low capacitance, high voltage cap (1uF,450V). This resistance increases when the capacitor ages, and it often does […]
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