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Hi, the voltage is input is actually a half-wave traingle so we would expect a 0 to 50% max duty cycle. This is because I am using op-amp to generate an AC triangle wave which I rectify with 1 diode only. I will build a full-rectifier maybe tonight to see the duty cycle would change from 0 to 100%. Thank you, eric

 

hi Mrss,
This is the circuit with Un4007, looks OK in simulation.

E
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Hi sir, I experiment it that when set the triangle wave input to be of higher frequency (13kHz) hoping that this circuit will output a very nice square wave, but its not that perfect. Are there any ways to make it output a nice square wave at high frequency. I have used the UF 4007 fast switching diode, so I believe the transistors need to be changed. Because, in LT Spice it output a very nice waveform

 

hi Mr.
Post your circuit, also what is the load on the output.?
E

 

hi Mr.
Post your circuit, also what is the load on the output.?
E

Hi sir, I am referring to the circuit that I posted some days ago. The circuit that I make onto the breadboard. When I increase the freuqency of traingle wave hoping the circuit will output a high frequency (20kHz) square wave, the square wave seems to have a slow rise time. According to LT Spice, this shouldnt happen

 

hi Mrss,
Your bread board built circuit has lots of capacitance on its contacts and wiring, also long leads have inductance.
All this extra capacitance and inductance will slow down the switching speed, so will not give square pulse edges.

How are you measuring the waveform output and is there any extra load on the output.?
E

 

hi Mrss,
Your bread board built circuit has lots of capacitance on its contacts and wiring, also long leads have inductance.
All this extra capacitance and inductance will slow down the switching speed, so will not give square pulse edges.

How are you measuring the waveform output and is there any extra load on the output.?
E

No load at output. I just follow your schematic

 

hi,
So, do you understand and agree with the comments in post #45.?
E

 

absolutely

 

hi Mrss,
OK, so what is your Plan B,?
E

 

hi Mrss,
OK, so what is your Plan B,?
E

What do you mean by Plan B haha?

 

What do you mean by Plan B haha?

hi,
Are you going to accept the poor square wave or build the circuit on a PCB or move on to the next project.?
E

 

hi,
Are you going to accept the poor square wave or build the circuit on a PCB or move on to the next project.?
E

Ah, I will accept it since I am still a begineer in electronics. I never touch a PCB before and extremely bad at soldering