LC meter that only measures capacitors

[karesz]

Re: LC meter

@ Karesz,
if you see the circuit uploaded by sanjubluerock3, the relay Calibhas a diode across the coil as it is expected to be operated by the transistor. Perhaps other one it is not needed as it is manually switched. Hope, this clarifies.
...

Sorry; I can not agree with you, because for the inductance its really equal if you are switching it per transistor or a manual switch onto some potential!
The answer will exists in all cases as a voltage transient, with amlitude depending of parasitics & not from kind of physical realising: Tr or Manual switch....
I will not say that a serial resistor(if its real existent in the Meter) can not attenuat it, but a diode not to design into these circuit i for me clearly=a failure!
K.

 

[mvs sarma]

Re: LC meter

Please try to make it work without loss of accuracy. it would be useful and you would have added a new dimension to the design.
all the best, karesz.

Added after 6 minutes:

@mvs I completely agree with you regarding accuracy of the LC Meter...since i built this circuit on PCB...thats why alot of factors could be considered for getting inaccurate results.... I also debugged the same circuit on a PCB created by my friend( which i would say the worst designed PCB i have ever seen)...Almost each n every fault lied in the PCB....But finally got it working The LC switch i was talking is the switch that is used to switch between unknown L or C to be measured Also a normal 6V relay could be used & drive it through PIC using npn transistor I wonder how u get such accurate results...can u measure Inductors in nH range....If possible please post ur designed PCB

the pcb designs uploaded were from me, and I gave to Sanjubluerock3.
originally i started with hand-wired board and it worked neatly.
Later i made the pcb as in silicon chip or EPEmag -both have published the design.
the board did not some how work for me. then i thought i would make one myself , it is the one you saw .

 

[karesz]

Re: LC meter

Please try to make it work without loss of accuracy. it would be useful and you would have added a new dimension to the design.
all the best, karesz.

Youu are nice_tnx!
But Im speaking not over L-C Meters accuracy, but over induced voltage of relays coil by switching it per hand switch or transistor .
I wish to finish these fruitless debate...
Greetings!
K.

 

[mvs sarma]

Re: LC meter

Please try to make it work without loss of accuracy. it would be useful and you would have added a new dimension to the design.
all the best, karesz.

Youu are nice_tnx!
But Im speaking not over L-C Meters accuracy, but over induced voltage of relays coil by switching it per hand switch or transistor .
I wish to finish these fruitless debate...
Greetings!
K.

Perhaps, one way you are correct, that, when we switch a relay on and later OFF , there would be spark across the switch contact that is wired on the coil.
After some number of operations the contact odd that switch fails. But with a diode in place, it would give much longer life for the contactof the switch.

 

[Fragrance]

Re: LC meter

Hi

The features are as follows:
- Measure inductance and capacitance.
- Auto ranging.
- Auto measure L or C.

Regards
Fragrance

 

[vsmGuy]

LC meter

Fragrance - as always you seem to have uploaded a project you tried yourself

How good did it work?

Could you upload the whole Proteus schematic and source code also?

 

[karesz]

LC meter

Hi,
For me are the schematics not to open/see :-(...
K.

 

[Fragrance]

Re: LC meter

Fragrance - as always you seem to have uploaded a project you tried yourself

How good did it work?

Could you upload the whole Proteus schematic and source code also?

Yes I have made it on strip board nice tool for my work bench and very accurate actually all detial are Available on link gevin under i attached the source code file along with proteus design file.

The software was written in basic. I don't use floating point math. This is a great example showing how to use integers to do floating point math. This program is far from done.

https://www.campworld.net/thewiki/pmwiki.php/Electronics/LCMeter

Regards
Fragrance

 

[yus]

Re: LC meter

OT:

PIC18F USB LC Meter (using pic18F2550):