1. boromyr

    Audio noise when touching the touchscreen

    While observing the audio output of my smartphone on the oscilloscope, I noticed a signal being generated when I touch the touchscreen. This signal is around 500Hz and appears in groups of 3 peaks, with intensity proportional to the skin/touchscreen contact area: The output is from an AUX cable...
  2. Younes Thabet

    what kind of noise can be introduced in an OPAMP conditioning circuit?

    Hello all, I have 2 almost similar PCBs for voltage and current measurement. I have used 230VAC from the outlet to test them both. The circuit in both boards is similar which is just a voltage divider to reduce the input voltage (see attached image). but I got some noise in one of them even...
  3. kpooja

    Baseline voltage not stabilizing

    Hello. I am trying to prepare a filter and amplifier circuit for a strain gauge (Wheatstone bridge in half-bridge configuration). Input power to the Wheatstone bridge is 1 VDC, and each output (+ve and -ve) of the Wheatstone bridge circuit goes the filter. The filter is a second order active...
  4. K

    How do I eliminate noise in an 8085 circuit?

    Hi, I am still relatively new to microprocessor circuits. Please tell me how I can reduce or eliminate the noise introduced into the circuit below? I have a half-decent power supply with a stable output voltage(input about 12 volts, output about 5 volts): But there is noise in the...
  5. A

    Obtain the expression of the noise figure for this circuit

    Here is the circuit: Here is the solution (taken from the book RF microelectronics by Behzad Razavi): My attempt: First i tried to find the gain expression for this circuit, i noticed that M2 is in diode configuration so in the small signal model M2 is equivalent to a resistor (=...
  6. wizardman1313

    How to remove noise from sensor data in python?

    Hello everyone. I have a sensor that I am continuously reading data from, at a constant rate, using python. Looking at the data there is obviously noise in it (bounces around when it should be zero or a constant value). After googling for 2 days I've not been able to find a way to remove the...
  7. T

    Does my sampling rate act as a low pass filter?

    If I sample a thermocouple at a slow rate such as 1 Hz, do I need Low Pass Filters? I'm not aware of any noise sources that are that low in frequency, and since I'm sampling so slowly, does this by default eliminate noise contributions in the high frequency ranges?
  8. S

    LM3429: LED driver make a lot of noise on FM-radio

    Hi, everyone! I've made a LED buck-boost (BB) driver based on LM3429. It's for automotive lighting, so Vin = 9-14.5 V, LED string consist of 10 white leds. V_out is about 30V, I_out=1.3A. All components were calculated according to LM3429 datasheet for BB topology. All datasheet recommendations...
  9. E

    Controller gets hang on Relay switching

    I am using a relay to turn ON/OFF the AC load. But when i turn ON and turn OFF the AC load (230 VAC) 3-4 times my controller gets hang. Here is my circuit diagram for the relay. The ground is common in all over schematic. What changes do I need to do for improving the noise?
  10. M

    Who Knows MOSFETs - Can Noise be Reduced? (Dimmer circuit)

    Hi, I created the following circuit here. The DIM Control Pin sources a 10uA current. I am getting 0.5V of noise on that pin (looking at the oscilloscope). It probably has to do with the GNDA being connected to the MOSFETs. And probably to do with my PCB layout. Currently, I don't have...
  11. A

    Three-phase EMI filter. LTspice

    Hello. Could you help me understand how to create a three-phase EMI filter? For example, I chose a full-bridge inverter with parameters P = 100kW, f_switch = 100 kHz. The noise measurement is performed using the LISN. The results of the simulation (calculation time 0-50ms) In this graph...
  12. pratyush13

    How does Noise is effected by inverter switch technique, output current, modulation index?

    How is the noise on the supply side effected by DC bus voltage, rise and fall (di/dt, dV/dt), switching frequency and techniques, modulation index and load current? Is there any formula or analysis we can do? Analytically?