Free electronic circuit design and schematic diagram
This is a over/under voltage monitor circuit. This circuit is used to monitor Any potential from 1 to 15 V. If there is a undesirable variation was occurs, two lamps will flash. The voltage differential fro lamp turn off and turn off is about 0.2V at any setting. Low and high set points are independent of each other. The type […]
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Standing wave ratio(SWR) is a ratio of amplitude of partial standing wave at maximum to amplitude at minimum. Using a Simple Swr Bridge circuit, a SWR can be measured. This circuit give a balanced VSWR meter perfectly, so adjustment is not required. This circuit can be made from a coupler which formed by a 6.5-inch piece of RG-58A/U coax. Here […]
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This is a Single-cell microphone amplifier circuit. This circuit produce a voltage gain of 60 dB at 500Ω load with bandwidth 5kHz. This circuit can provide a 60dB gain up to 10kHz if it is unloaded. This circuit has a 10 kΩ input impedance. This circuit cannot neither produce an output swing closer than 800mV or below 150mV to the […]
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This is a Frequency Difference Measurement circuit. This circuit consist of two TC9400 that is configured in the F/V mode. So, the TC9400 will convert both frequencies into proportional analog voltage(V1 and V2). This circuit also uses unity gain inverter to invert V2. After that, this circuit will add the V1 and -V2 using the summing op-amp. That operation will […]
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Below is two single ended circuits which connected back to back give differential input. This circuit is not only has differential input feature, but also high impedance, much higher compared with the analog ammeter without this circuit. Here is the schematic diagram of the circuit: [Circuit’s schematic diagram source: seekic.com]
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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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Featuring very low power consumption, 675 nA is the total current consumption for this amplifier circuit. The output voltage swing is 300 mVpp with a 20 kΩ load. This very low power design is made possible by high gain low power operational amplifier CA3078. CA3037 is marked as obsolete product by Intersil, but they suggest ICL7611, ICL7612, CA5420A, CA3140, or CA3160 for […]
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