Dear Stefan, That is a nice simple circuit - I may well try something very similar at my QTH over the Christmas holiday, if time allows... I suppose one advantage of a passive, "signal powered" phase
In that case - you could try a non-linear amplifier, with a high gain until the magnitude of the output voltage is around 4V then reducing. Makie the opamp feedback R of two elements, then shunt one
Hello Andy, Thanks for the discussion. Always good to see different ways and solutions. Yes, that's another way to reduce the 4V problem in my case. But maybe it is even a bit more critical. Dependin
Stefan Good new on the variometer ... guess this means you're one step closer to 0 dBfs! Another 3 - 6 dB and I'll need welding goggles to safetly view the signal. Looking forward to receiving your s
This is a terrific achievement and you are so excited, if you need one. In my case I DO NOT G3KEV http://dl.dropbox.com/u/19882028/LF/LF_variometer_drive_engine_arrangement.j pg http://dl.dropbox.com
Hello Jim, Thank you. I ran the circuit unattended over night with a somewhat cautious feeling but the system is still fine ;-) Now beeing here on the Grabber PC again and watch how it works in opera
Maybe you need one, you seem to have gone off Resonance!!!!!!!!!!!!!!! again. A variometer is hardly rocket science. Mal, Are you totally unable to say ANYTHING good, supportive or kind to anyone? St
Dear all, from my memory I would like to support the view of Andy concerning a linear system. On one occasion around 1975 I also had to design an automatic tuning system for a transmitter tank circui
Hi Andy, Thanks for the hint. I intended to use a hard drive since the motor does not rotate when supplied with < 4 V DC. So it would always stop before the resonance is reached. That problem may be
Jim, Another thought: Am 23.12.2011 12:17, schrieb James Moritz: [...] I guess the inertia of the motor and gearbox will produce some hysteresis, moving the variometer to a very slightly over-adjuste
Am 23.12.2011 16:12, schrieb Stefan Schäfer: [...]But what i want to do is to make the resistor smaller and reduce the output voltage a bit, making the behaviour of the source come closer to an ideal
Stefan.. An idea. You have implemented a bang-bang driver with a dead zone. Switched hard on in either direction, or stopped close to the middle. Change the circuit so you linearly amplify the output
Mal, Are you totally unable to say ANYTHING good, supportive or kind to anyone? Stefan does not need, or deserve, your sarcasm or ill will and neither do the rest of us. Please, have the good grace t
