So I went and bought a pair of San Ace 120 finger blenders and have been contemplating building my own PWM controller rather than running the PWM from a motherboard 4-pin fan header to them.
In fact, I bought a Magnum soldering station for the hell of it and just dying to melt some metal glue.
The idea is to run it off the more common 3-pin 12V headers. The 12V signal will be used to generate a PWM signal (0-5V).
Anyway, some thoughts and questions ...
Q1: should I bugger off and go ask on an electronics forum instead?
Q2: if the accepted norm for PWM for PC fan control is using a 25kHz frequency to avoid audible switching noise, could one perhaps achieve the same by using a very low switching frequency?
Q3: I decided against the 555/556 approach and want to use opamps instead. Most circuits I've seen don't seem to be designed for as high a frequency as 25kHz with their selected components. However, theory of operation is the same amongst all of them. The question is: how can tell if an opamp will be able to generate a PWM signal of 25kHz, or rather be able to generate the required triangle waveform of 25kHz? Should I be looking at the gain-bandwidth figure?
Q4: If my opamp is running off a 0-Vcc voltage, would the resulting PWM signal be 0-Vcc or is it usually the case that it is slightly off those figures (eg. with 0-5V I'd see 0.5-45V swing)?
Q5: should I return the soldering station and SanAce fans and take up baking instead?
And, yes, opamp operational theory is well beyond me. I'm just starting to mess with the electronics a bit, even at my "rapidly advancing" age.
In fact, I bought a Magnum soldering station for the hell of it and just dying to melt some metal glue.
The idea is to run it off the more common 3-pin 12V headers. The 12V signal will be used to generate a PWM signal (0-5V).
Anyway, some thoughts and questions ...
Q1: should I bugger off and go ask on an electronics forum instead?
Q2: if the accepted norm for PWM for PC fan control is using a 25kHz frequency to avoid audible switching noise, could one perhaps achieve the same by using a very low switching frequency?
Q3: I decided against the 555/556 approach and want to use opamps instead. Most circuits I've seen don't seem to be designed for as high a frequency as 25kHz with their selected components. However, theory of operation is the same amongst all of them. The question is: how can tell if an opamp will be able to generate a PWM signal of 25kHz, or rather be able to generate the required triangle waveform of 25kHz? Should I be looking at the gain-bandwidth figure?
Q4: If my opamp is running off a 0-Vcc voltage, would the resulting PWM signal be 0-Vcc or is it usually the case that it is slightly off those figures (eg. with 0-5V I'd see 0.5-45V swing)?
Q5: should I return the soldering station and SanAce fans and take up baking instead?
And, yes, opamp operational theory is well beyond me. I'm just starting to mess with the electronics a bit, even at my "rapidly advancing" age.