1. MrsssSu

    Buffer AM signal (5W)

    Dear all, may I ask how to buffer an AM Signal so that it contains more power, maybe 5W for my Remote Control RC? I have buffered the AM signal using op-amp but the power output is just not enough. I have tried using this push-pull transistor pair, but the waveform seems to be unbuffered. I...
  2. JLoundy

    Small-Signal Analysis Symbolic equation for voltage at x?

    I am having trouble finding a symbolic voltage at node x for this circuit using small-signal analysis. Any thoughts would be appreciated.
  3. MrsssSu

    Linear Frequency to Linear Voltage circuit

    Dear all, the circuit above is quoted from here, and I wish to try to produce similar graph in LT Spice but I am unsure of it. The LT Spice schematic is correct since I tested it with specific 10V input AC, and it produces linear voltage on its output. However, I want to do an AC sweep on this...
  4. MrsssSu

    Reduce Frequency of Waveform

    Dear all, may I ask if there is a circuit that produces the following input and output which basically reduces its frequency by 2 times which also basically stretch out the input waveform to produce the following output? Thank you for reading :)
  5. MrsssSu

    How to freeze CD 4017 (Rain Led Chip)

    Dear all, I have successfully simulated a continuous led array that light up consecutively one after another using LT Spice and have even built one on breadboard and it works well. Well, my question is how would you freeze the led and how do we activate the clock inhibit on both the chips? Like...
  6. C

    Driving motors with atmega

    Is this circuit okay to drive dc motors with atmega? While sending to one signal input other one will be grounded from microcontroller. If not okay what additions or substractions are needed to create ideal h-bridge for dc motors to drive with atmega?
  7. Topad

    Output logic source and sink

    Hi all, Im working to design a circuit that can sink after a load is apply, but when there's no load also be able to output logic levels 5v/0v. The max that a load could be is 12V and not not more than 100ma, therefore I decided to use octocapulers to make some output logic. In my attach image...
  8. ajob

    What am I missing on my interpration to the following circuit?

    Well... I set up the following circuit and it didn't work as I expected. At this point, I'm no longer interested in "Why didn't it work?" question, but on "Why does it work like this?". Below I will describe how I think it should happen when I press SW1 and then I will tell you what actually...
  9. MrsssSu

    Amplify High frequency microvolts sine wave

    Dear all, I simulated a radio-receiver circuit, where I have actually build a part of the circuit which helps to amplify a sine 550kHz frequency of microvolts (antenna voltage) into several volts, however, I do not see any amplification on the output as highlighted above where I attached a...
  10. MrsssSu

    How to buffer AM signal?

    Dear all, I have actually built an AM circuit in real life to combine high frequency carrier sine wave (200kHz) and signal wave of triangle wave at (3kHz), and the output is on my oscillioscope which I am happy about. However, when I try to resonant the wave on my oscillioscope using LC tank...
  11. MrsssSu

    TL072 LT Spice Model

    Dear all, can anyone share TL072 op-amp LT Spice Model with me (probably better if placed in zip file ) ? I am trying to simulate a TL072 to produce 1MegaHertz sine wave :) Thank you for your help :)
  12. MrsssSu

    RLC resonator to produce beautiful sine wave

    Dear all, I have read about the RLC tank which can help to resonate a pulse wave of a certain frequency so that it will produce a beautiful sine wave. What would be the values of R , L and C if a 150kHz pulse square wave is used to produce a beautiful 150kHz sine wave? From what I simulated, I...
  13. MrsssSu

    AM modulation and demodulation circuit

    Dear all, above shows a modulator (transmitter) and a demodulator (receiver) and the circuit works well. However, this circuit only works if the transmitter and receiver are attached by wire. What modifications should be made to transmit the wave signal wirelessly from the transmitter to...
  14. MrsssSu

    Amplify tiny voltages accurately

    Hi all, above is a Schering's Bridge as a capacitance meter. Following the equation below, Rx resistor is fixed, whereas for capacitor Cx can be placed with an unknown value capacitor. R1 will be adjusted until voltage across R4 will be 0. The problem is that the voltage fluctuation across R4...
  15. MrsssSu

    Demodulator circuit

    Below is Triangular Modulation Output of a Triangle input wave HI all, I have been trying to understand modulation and demodulation circuitry as part of my hobby :) The modulation circuit above works fine but when I connect the output of the modulator to the demodulator (as shown by blue...
  16. MrsssSu

    TA7642 LT Spice model

    Hi all, can anyone share TA7642 LT Spice model ? This IC is used in transceiver radio to demodulate the AM signal. I have tried to search the web but I could not find any of it. Datasheet is here . Thank you :)
  17. MrsssSu

    Buffer an input signal while maintaining the same input waveform undistorted

    Dear all, above shows an AM (Amplitude Modulated Signal), I was just wondering how can I make the AM waveform to have a very low impendence so that it is able to transmit high power. One solution I tried is using an op-amp as buffer which can reduce impendence while keeping the shape of waveform...
  18. MrsssSu

    Voltage Modulation Circuit

    Hi all :), I tried to simulate a modulation circuit which uses a comparator, following this click here . The output I get at the 1 kΩ resistor is weird; it should be the same shape as the send signal above. May I know what values of capacitor and inductor are used, and whether the resistor...
  19. MrsssSu

    Increase Input Frequency circuit

    Referring to website link at here , this circuit tries to replicate the waveform of input voltage and make it to a high frequency, I try to simulate the circuit in LT Spice but the output is weird. May I know the solution to this? Below is my attached LT Spice for your convenience. Thank you...
  20. MrsssSu

    2 way radio transmitter walkie talkie product schematic

    Hi all, I am trying to search for this FLNROSE walkie talkie datasheet in the web but I couldn't find any. May I know if someone is able to find this walkie-talkie datasheet from web because I plan to get the schematic in datasheet on how this walkie-talkie works and try to desolder all...