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LT6015 opamp and LTSpice simulation – I am wondering why the simulation of the scheme attached is working. Should an opamp configured like an inverter work when the input voltage is negative and the power supply is between 0 and a positive voltage? Read more
Common gate impedance matching – I have a ham radio that uses a microphone that has 50kΩ impedance. But I want to connect a microphone that has 600Ω impedance instead. I read that you can make an impedance matching circuit with JFET, basically this schematic.
Rd=50k, Rs=600Ω Can it be done this way? Read more
High-gain microphone preamplifier circuit bottleneck – I’m making a sound level alarm, a simple device that will turn on a light if the sound level is above a certain level. For this I would like it to have the ability to be really sensitive, but I’m not sure how to achieve that. Right now I’m using one of those cheap through-hole electric mics with an LMV358 op-amp, but there’s a limit to how much gain I can have before noise becomes a serious issue. Perhaps I can increase the gain if I go for a really low noise opamp? Read more
Hall sensor output voltage problem – Page 20 of the ACS724 Hall sensor datasheet says that its output when sensed current is zero is Vcc/2. Why should this be so for the unidirectional version? Read more
Fifth order passive filter – I have to design a fifth order passive filter for my circuit. I know well the classic RLC circuit and higher order but not the ACTIVE filter. Can someone recommend software tools, documentation or something like that to design the filter? Read more
Minor variation in voltage – I am using a 7.4V Li Ion Battery, followed by a 5V (1117) regulator, the output of which is given to 1117 (3.3V). The input (Li Ion) voltage depending on load is fluctuating (dropping to say 6.8V). I am connecting aBluetoothh module also at 3.3V. I closely looked and I saw that 3.3V drops 200-300mV (approx) for about 7ms and comes back to 3.3V and some spikes (lots of up down lines on CRO) of few mV variations. I think this is affecting the Bluetooth throughput. How can I make sure that the voltage is stable? Read more
How to monitor battery voltage -I have made this circuit to monitor battery voltage. Is this correct? Read more
What’s the diode function in the peak detector? – Why is there a diode (red circle) in the peak-detector circuit? Read more
Standard sampling rate and increasing sampling rate – When we sample an analog signal we follow the Nyquist theorem where the sampling rate has to be twice the highest frequency component. I read that sampling rates even higher than twice the highest frequency is utilized. But can anyone tell me why the sampling rate chosen is twice above highest frequency? Does this make the converted data in the audible frequency range? And what difference would it make in the audio if the sampling rate is increased? Read more
ADS error message while running simulation – There is an error message popping up when I am running my stimulation. Can anyone helps me to understand the error and guide me to fix it? Read more
