Hi,
I am currently designing an LRC meter that is based on the principle of measuring the frequency of a precision tank circuit with your DUT connected in parallel and then calculating the DUT by knowing the difference in frequency.
Very Accurate LC Meter based on PIC16F628A
My frequency measurement although is based on the Microchip CTMU where I can measure time period in resolution of 1ns and even less I use an external adc(higher bits).
My question is about measuring the Q-factor of small inductors at least. This is because my meter will be aimed for modern switch mode power supply design. I read that today, frequencies had increased to 100khz-120Khz. By using the best core material and good winding wire, would the q-factor be so significant? (I assume yes since the incductor would be small in value).
Another thing: Would hysteresis alter the Q-factor(Dc resistance) significantly at those frequencies and for such an application?
Would I be able to measure the Q-factor by taking advantage of the damped harmonic oscillation phenomena and measure the frequency of my tank circuit(with DUT attached) at different periods while the oscillation is being damped slowly. That way I can account for the hysteresis since the static tank circuit could be set to oscillate at the frequency range (100khz-120khz).
I would really appreciate any hints, thanks
I am currently designing an LRC meter that is based on the principle of measuring the frequency of a precision tank circuit with your DUT connected in parallel and then calculating the DUT by knowing the difference in frequency.
Very Accurate LC Meter based on PIC16F628A
My frequency measurement although is based on the Microchip CTMU where I can measure time period in resolution of 1ns and even less I use an external adc(higher bits).
My question is about measuring the Q-factor of small inductors at least. This is because my meter will be aimed for modern switch mode power supply design. I read that today, frequencies had increased to 100khz-120Khz. By using the best core material and good winding wire, would the q-factor be so significant? (I assume yes since the incductor would be small in value).
Another thing: Would hysteresis alter the Q-factor(Dc resistance) significantly at those frequencies and for such an application?
Would I be able to measure the Q-factor by taking advantage of the damped harmonic oscillation phenomena and measure the frequency of my tank circuit(with DUT attached) at different periods while the oscillation is being damped slowly. That way I can account for the hysteresis since the static tank circuit could be set to oscillate at the frequency range (100khz-120khz).
I would really appreciate any hints, thanks
You might want to increase that frequency some.
3.5 MHZ converter.
DC/DC Converter (Integrated Switch) - Step-Up Regulator - TPS61256 - TI.com
3.5 MHZ converter.
DC/DC Converter (Integrated Switch) - Step-Up Regulator - TPS61256 - TI.com
Hi,
thanks for your reply. What is the best method to measure the peak voltage at the inductor at those frequencies? I will be using 32Mhz PIC24F with 500ksps adc.
thanks for your reply. What is the best method to measure the peak voltage at the inductor at those frequencies? I will be using 32Mhz PIC24F with 500ksps adc.
- Status
- Not open for further replies.