| ??? 01/17/05 03:31 Modified: 01/17/05 03:35 Read: times |
#85070 - Re: ' Detailed Answer' Responding to: ???'s previous message |
Dear Kai,
Thanks a lot for poinitng me to your post. After reading the formulae you gave things are clear now. But How do I measure the inductance of my coils. One way is to make a R+Coil combination using some suitable resistor and apply 50Hz sinus signal and then measure the potentional drops across R and coil and then find Z of coil.
Vc Vr
|------------------|
-|-///--(((((((--|------//////---|
| | Rc wL | Rr |
| |------------------- |
| Zc Coil |
| |
|----------------(50Hz 24Volts)-------------|
Rr= Resistance of resistor. Rc= DC Resistance of Coil. Zc= Impedence of coil. L = Inductance of coil. Vr= Voltage drop across resistor. Vc= Voltage drop across coil. Zc/Rr=Vr/Vc Thus, Zc=Vr*Rr/Vc -----(1) next, wL=Zc-Rc L=(Zc-Rc)/w = (Zc-Rc)/(2*PI*50) -------(2) Combining 1 and 2 L=((Vr*Rr/Vc)-Rc)/(2*PI*50) L=((Vr*Rr/Vc)-Rc)/314.16 ------ Final Formula Vr, Rr, Vc and Rc can be measured using a DVM. Kai, Is the above formula and method correct for finding L. Is there any simple method for finding L of a coil. Thanks & Regards, Prahlad Purohit. |
| Topic | Author | Date |
| Source Impedance | 01/01/70 00:00 | |
| Re | 01/01/70 00:00 | |
| Impedance measurement | 01/01/70 00:00 | |
| Being more concrete | 01/01/70 00:00 | |
| What about my Rogowski Coils. | 01/01/70 00:00 | |
| Already answered in detail! | 01/01/70 00:00 | |
| Re: ' Detailed Answer' | 01/01/70 00:00 | |
| Bridge | 01/01/70 00:00 | |
| What Bridge, | 01/01/70 00:00 | |
| bridge | 01/01/70 00:00 | |
| and ... | 01/01/70 00:00 | |
| Using an OPamp | 01/01/70 00:00 | |
| Using OpAmp | 01/01/70 00:00 | |
| Some disadvantages | 01/01/70 00:00 | |
| Correct formula | 01/01/70 00:00 | |
| Thanks Kai, | 01/01/70 00:00 | |
| LCR meters quite common | 01/01/70 00:00 | |
Re: LCR Meter. | 01/01/70 00:00 | |
| Resonant coupling... | 01/01/70 00:00 | |
| Sorry! | 01/01/70 00:00 | |
| Go with the rule of Thumb | 01/01/70 00:00 | |
| No more than about 10kOhm | 01/01/70 00:00 | |
| Line drops | 01/01/70 00:00 | |
| Thicker cable | 01/01/70 00:00 | |
| Freq domain analysis | 01/01/70 00:00 | |
| re: Source Impedance and driver types | 01/01/70 00:00 | |
| universal solution | 01/01/70 00:00 | |
| Thanks .... | 01/01/70 00:00 |