LCFESR precise, wide range LC LCF LCR in-circuit ESR frequency meter tester with DIY KIT based on AVR processor


LCFesR 4.5 unit is a precise, wide range LC / LCF / LCR / ESR meter (tester / checker) that measures inductance (L), capacity (C), frequency (F), small resistance (R) and equivalent series resistance (ESR) of a capacitor inside an electronic circuit (in-circuit). It can measure the internal resistance of a battery / rechargeable battery too. The meter can be built easily with one- or double-sided throughole PCB and available electronic components (DIY). It's functions are base on an further developed AVR ATMega88PA microprocessor. There are 4 options to build or get a meter:
- You can build yourself a meter to test with the DEMO software
- You can get a preprogrammed and in-meter tested through hole processor for a very reasonable price and build yourself a meter in through hole version - the cheapest solution that requires some hard work
- You can get an assembled, thoroughly tested and calibrated KIT meter with 2-side professional SMD PCB together with an assembled LCD display - the fastest solution to get a multifunction, calibrated, ready for work meter for a very reasonable price
- There is a possibility to get a more affordable, about 80% assembled DIY KIT with all the SMD components being reflow soldered in advance on the PCB and all you have to do is soldering a few through hole components, the rotary switch, the ribboncables to the LCD display and at the end calibrating the meter - the cheaper solution that requires some work.

LCFesR meter's some beneficial properties:

- It is surprisingly accurate (checked by professional meter - see documentation and videos below), despite of that it can be built cheaply.
- It has wide range (compared to other meters LCF ESR meter has wider range - see documentation).
- Ease of use: it is enough to wring the rotary switch.
- Easy calibration: it is enough to use a button to setup the software configuration.
- Measurement of capacitor C is continuous and convenient: no need to switch to different measurement ranges.
- Before measuring capacitor C, there is no need to discharge capacitor charged to small voltage (some professional meters require doing this to protect them).
- Measurement of capacitor in pF range is good enough (some meters can not or do it with very large measurement error).
- Measurement of inductor in nH range is stable enough so such air-core inductors can be measured well. Measurement of larger (H value) inductor is accurate and larger toroid inductors can be measured too, thanks to Schmitt trigger IC 4093 (some other type meter could not measure larger toroid inductors because the resonance would not start).
- Inductors (transformers) with inductance between 200mH-4H can be measured with 2 frequencies (a few 100Hz and a few KHz) so their frequency-dependence can be examined.
- Measurement of frequency F is continuous and convenient: no need to switch to different measurement ranges.
- Measurement of ESR is continuous, in-circuit, polarity-independent, max. measuring voltage is 300 mV peak. In-circuit measurements means: ESR of capacitor in PCB can be measured directly, that is no need to desolder the capacitor to test it. In other words: the results of the ESR measurement is not affected by any other semiconductor part, bigger resistance, small ceramic capacitor that is connected paralell to the capacitor under test.
- At measurement of ESR / R the meter will automatically change the measuring current to get more accurate measurement results.
- The measurement of resistance is accurate in all the range (some other type meters when using in-circuit mode can not measure accurately resistance of value more than a few Ohms).
- LCFesR is directly measuring ESR of C in-circuit so there is no need for additional circuit that is uncomfortable to use: additional circuit have to be put on and removed.
- At measurement of ESR the meter is protected from capacitor charged up to 100V voltage (some professional meters go wrong from charged capacitors).
- At measurement of ESR the meter uses fast discharging circuit, so ESR of big capacitors can be measured fast too.
- LCFesR meter in ESR measuring mode can measure the internal resistance of a battery / rechargeable battery (from 1.2V to 12V) so the actual condtion of the battery can be determined indepedent of the level of its charge (that is we will know how much good or worn it is) (see documentation for more details).
- Low cost only in-circuit ESR meter can be made: electric parts for the LC and the F measurement may be omitted. Then the rotary switch is not needed either (see alternative use).
- Low cost only LC or LCF meter can be made: electric parts for the ESR measurement may be omitted.
- Some critical electric parts can be any value within their range: capacitor from 10 nF to 15 nF, inductor from 1 uH to 2.2 uH can be used (software will handle these values).

(See the documentation for more details).