M
Merlin
- Jan 1, 1970
- 0
Hi,
I have been experimenting with making an oscillator circuit running around
400-500 kHz (some of you probably recognize this from previous questions). So
far out of 3 different designs I keep getting practical results that are far
below the calculated ones.
I have been breadboarding the circuits and I know that breadboards have a
certain amount of capacitance in them. But could the breadboard be the reason
for a large discrepancy between expected and observed frequencies at frequencies
around 500kHz?
It seems that calculated vs observed differences get worse as I increase in
frequency. It is relatively close around 80kHz but as I ramp up the frequency
the output amplitude decreases and eventually the oscillator stops. The best I
seem to get is 140kHz to 250kHz depending on which design I use. In both cases
the calculated values should give around 480kHz.
I have thought of using a proto board of some sort instead of breadboard but I
was hesitant about spending the time soldering together another failure.
Any practical insite would be appreciated.
Merlin.
I have been experimenting with making an oscillator circuit running around
400-500 kHz (some of you probably recognize this from previous questions). So
far out of 3 different designs I keep getting practical results that are far
below the calculated ones.
I have been breadboarding the circuits and I know that breadboards have a
certain amount of capacitance in them. But could the breadboard be the reason
for a large discrepancy between expected and observed frequencies at frequencies
around 500kHz?
It seems that calculated vs observed differences get worse as I increase in
frequency. It is relatively close around 80kHz but as I ramp up the frequency
the output amplitude decreases and eventually the oscillator stops. The best I
seem to get is 140kHz to 250kHz depending on which design I use. In both cases
the calculated values should give around 480kHz.
I have thought of using a proto board of some sort instead of breadboard but I
was hesitant about spending the time soldering together another failure.
Any practical insite would be appreciated.
Merlin.