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Sencore

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clel miller

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Any of you guys have experience (or own) the LC75 Z Meter.?
Just wondering if you would buy one Today, used.
Sencore was sold a few years back I think. At any rate, they are into AV "stuff" now, and they no longer support any of their old service equipment. They do not even archive the manuals.
Sooooo......I would have no idea how to Check/Calibrate one of these if I did buy it.
Is there a modern day equivalent, that does not cost 1k dollars+ ....... or are these still a good piece of equipment to buy.?
Thank You
 
Call them:. They will likely have manuals.

There is always a short/open calibrate function for LCR meters. You short the leads and do a short test and open them to do an open test. All frequencies that the meter supports are calibrated.

LCR meters that can do DC bias are hard to come buy and expensive. Some high end meters require you to set a particular OSC level for the calibration.

I have the HP/Agilent/Keysight U1733c

There is a thread at ETO about a very cheap (<$20) component tester kit sold by www.banggood.com.
 
Value = specs/needs=k

e.g. K= 1/(error%*resolution(pF))

You do the math
replace pF with uH and repeat.... Miliohms... Q, DF, f range

This is why they range $2 to $2k typ.
 
or $120k USD **broken link removed** plus options
 
Somewhat DEPENDS on How Much you need to pay for one?

Originally I Had the LC53, but later sold it as I got a Great Deal on the LC102.
And I still use the LC102.
I have the Manuals for Both these.

The LC75 is probably Similar.

Both of these are good meters.

Now the TV Service Industry is almost Dead, so this type of equipment is not profitable for Sencore anymore.
Almost All the Electronics today is Throw Away, Not Repairable.
 
No , the cost depends on your needs for resolution, accuracy and spectrum, as I previously stated.
 
the cost depends on your needs for resolution, accuracy and spectrum,
Click to expand...
Erm...
Is that not what chemelec just said:
Somewhat DEPENDS on How Much you need to pay for one?
Click to expand...

Come on guys, lets just stop the willy waving about how much the test gear costs and get back on track to try and comment about the OPs LC75 meter.

JimB
 
In My Opinion, The Main Advantage of the Sencore units is they Actually Tests capacitors at their Rated Voltage, Up to 1000 Volts.
And Shows the actual Leakage in uA., as well as a Chart to show Typical leakage rates for various Caps.
A Big Advantage for testing Electrolytic Caps.

As to the Actual Tests for Inductance or Capacitance, It is no more Accurate than a B&K 878, LCR Meter or many other testers.
And the Sencore unit only does a Inductor "Ring" Test on Coils.
It Does Not give a "Q" Value like most other Inductor testers.

I was Really Lucky, I got the LC102 for $25,00 at an Auction.
It was Not an Electronic Auction (Mostly Warehouse Items) and seems no one Knew what it was or its value at the time.
After getting it, I phoned Sencore and they Supplied me with the Manual for Free.
 
Ω
JimB said:
Erm...
Is that not what chemelec just said:


Come on guys, lets just stop the willy waving about how much the test gear costs and get back on track to try and comment about the OPs LC75 meter.

JimB
Click to expand...
The problem with most newbie questions including this , is undefined requirements.
If one does not know how to use it, or what features are useful, and one wants to pay as little as possible , yet be able to use it for a long time, how can anyone offer useful opinions without requirements?

  • I prefer my Extech 380193 LCR Meter for many reasons;
  • It does everything I need, including battery charge that lasts for years with occasional use and auto-shutoff.
  • It will last forever , made by a TW company with experience since 1971.
  • It will automate settings for simultaneneous LCR Q,D,Rs or Rp at 120 or 1kHz. Others may need 1MHz. You can test in-circuit and change any setting with one button.
  • It has RS-232, automated binning for Hi/Lo tolerances with alarm.
  • 5 digit resolution and auto zero for RLC prior to use.
  • Range is from 0.1pF to 10.000mF or 0.1uH to 10,000H, 1mΩ to 10.000MΩ and Q from 0 to 9999 ( not GΩ or 1F )
  • With accuracy far better than all passives.
  • It has two receptacles for leaded component insertion or banana sockets with alligator clips.

  • It does not have a HV supply for measuring non-linear bias leakage of caps, which the LC75 does have.
  • In every other aspect, it exceeds the LC75. $350 10yrs ago.
 
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I used it once to measure the Henries and coupling capacitance on a 5000 KVA distribution transformer, something I never thought I would want or need to , when I bought it. It was quite useful to troubleshoot an epidemic process failure in that factory which refurbished distribution transformers. The coupling capacitance of cold-rolled grain oriented Silicon Steel laminations in the core is about 0.1uF per layer with hundreds of layers, some which were shorted on the broken edges. So the edge resistance varied from ohms to kohms to mohms and thus inversely so did uF and thus a risk for ionization at low voltage e.g. 10V . This gets created or exacerbated a dual layer charge build up and mobility of electrons higher than protons. Essential a huge capacitance transformer to low voltage discharge; Which was invisible but measurable and occurs across the laminate layers with 0.3mm gap coated with 1~3um silicate insulation, which was the primary source of contamination and detonation of transformer oil, causing a rapid rise of dissolved Hydrogen and Methane to reach lower explosive limits in 3 months rather than 30 years.

The primary fault was contaminated oil from magnetic charged silicate/SiliconSteel particles that accepted charges and only took 60% of the primary line voltage to begin a Relaxation oscillator effect called Partial Discharge (PD) thats starts detonating voids or particles in insulation at 1 ppm and rises rapidly to hundreds of pulses per second >>100 pps at rated line voltage. It consumed about 10W per discharge that I measured on a CT with 300MHz DSO and at this slow rate was undetectable by the factory and customer safety and performance tests. IEC is quickly adopting these type of test but too slow to make it mandatory for <10MVA class.

  • The lesson learnt here and ignored by most Indian, North American and other suppliers of high voltage transformers is ignorance of PDIV and PDEV as a mandatory factory test on the dielectric, rather than an option "type test " specified by the wiser customer.

The explosion of the defective microscopic particles only lasts 10 ns to us with rise time <1 ns depending on size of defect and heats up surrounding dielectric to break down the long hydrocarbon chain HxCy into H2 and other gas molecules in smaller proportions. This resulted in rise of H2 measured by customer in monthly $75 DGA sample tests for a $50k transformer but can result in a million dollar problem if ignored.

Interesting how dielectric gets complicated by defects. But this ultimately , is unavoidable, even in a Class 100 clean room. But is why you should be careful when choosing a capacitor vendor, and why Japanese make the best, due their attention to details and specs for quality of materials, air, environment, process for contamination.
 
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chemelec said:
In My Opinion, The Main Advantage of the Sencore units is they Actually Tests capacitors at their Rated Voltage, Up to 1000 Volts.
And Shows the actual Leakage in uA., as well as a Chart to show Typical leakage rates for various Caps.
A Big Advantage for testing Electrolytic Caps.
Click to expand...
Exactly my interest in the LC75. In circuit, and at 400-500 VDC.
A 200-300 dollar LCR meter will handle any needs I may ever have.
Testing Elytics, wired to turrets, and with operating B+ is what attracts me to the Sencore.
Thank You
 
The Secore tester does Not test Caps when Charged up in Other Circuits.

The LC102 Actually Generates this Test Voltage up to 1000 Volts and displays the Leakage Current.
It can also operate as a Portable Unit, using a 12 Volt Gell Cell.
(The Gell Cell goes inside the back of the tester.)
 
The LC102 Does Test the ESR of Capacitors, but Not in-circuit.
And I doubt that the LC75 could do that also, When in a circuit.

When a Capacitor is in a Circuit, it could have Other Resistive Paths around the cap, creating an error in the reading.
 
I work on Very Specific circuits. All the E Caps I see are in a B+ rail with no resistors/caps hanging off of them. My 100 dollar Blue Meter will do that. My attraction to the 75 was to get on caps with B+ applied .....the Blue Meter needs to measure discharged caps.
 
Either Way, I Doubt it will measure them in that way.
And If Charged, It will Probably Damage the Meter.
Just Phone Sencore and ask them!
 
Do you mean This:
"Allows capacitors to be checked for value, ESR and leakage at their rated working voltage (up to 600VDC)".

If So, the Answer is YES.
But only from the Internal Supply Voltage put out by the LC75.

As it also Says:
CAPACITORS (Out-of-Circuit):
 
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