# voltage

1. ### 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 :)

Hi, I have a problem where a simple bush button makes a 3.2V into a 2.8V. I wonder if there is any way to fix this or if every button does this. Thanks in advance :-)
3. ### 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...
4. ### 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...
5. ### 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...
6. ### 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...
7. ### 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 :)
8. ### 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...
9. ### 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...
10. ### 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...
11. ### 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...
12. ### DIY walkie-talkie circuit

Hi all:), I have been trying to find circuits to make my own DIY walkie-talkie. Referring to video at here, the Jumper wires(yellow), is it just a wire connection from 1 to 2 ? If so, why need Jumper? Does this circuit works by converting our audible frequency sound to higher frequency sound...
13. ### Reset an NE555 timer at a specific point

Dear readers, if I want to reset an NE555 timer (by pushing a button within a time frame) at the point where the output signal is at the end of the high voltage as highlighted in the diagram. How can I accomplish this? Thank you for reading and have a nice weekend:)
14. ### Press same button 3 times to on an led

Dear all, I am looking for a circuit that can on an led by pressing the same button for 3 times? Thank you for reading and have a nice day:)
15. ### 3 led on consecutively with different time intervals

Above is related from here but this ic only allows the led to be on at the same time interval. Is there a circuit which can help to activate 3 led consecutively for different time intervals. For example, led 1 will on for 3s (the other 2 led will be off), followed by led 2 will be on for 2s (the...
16. ### Determining Amplifier Input Power

Hi All, I am trying to setup my Sony N500 Xplod Car Amplifier in home environment. I have presently a 20A fuse placed in a 25A socket of the Amplifier. Its input is 12V. So I believe a SMPS of 25A 12V will suffice its working. I am intending to change the 20A fuse to 25A as well to support...
17. ### 74HCT library file LT Spice

Hi all, does anyone have the 74HCT.lib with the square symbol of 74HCT.lib :)? Do you mind sharing it because I am having a hard time googling the one with a square symbol as shown above? Thank you and appreciate it :)
18. ### D-type Flip Flop using logic gates, LTspice says "timestep too small!"

Both pictures are quoted from here and here. I am trying to simulate it in LT Spice using Logic gates as the Level Triggered D Type Flip-flop and this circuit converts f to f/2 that is halving the input frequency. However, I got the error timestep is too small in LT Spice. May I know how to...
19. ### Rain Drop Led

Above is quoted from here. This circuit produces beautiful rain drop led. May I know how do I actually increase the deadtime which means all led are off for a longer period for all the 4 led as shown above? My LT Spice file is below. Thank you :)