Multi-Function Tester TC1

[soggybag]

Has anyone tried one of these? I just got one for $17 it seemed like a pretty good deal.

I charged it up but it doesn't seemed to work. The screen lights up all white. Seems like there is something wrong with the micro controller that runs it?

https://www.ebay.com/itm/LCR-TC1-Transistor-Tester-Didoe-Triode-Capacitance-Resistor-NPN-PNP-Detecto-H6Z2/132151326011?rt=nc&_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D52885%26meid%3D19f9a556e74642399779c894953471b3%26pid%3D100005%26rk%3D3%26rkt%3D12%26sd%3D111940309872%26itm%3D132151326011&_trksid=p2047675.c100005.m1851

[vigilante397]

Looks really similar to a lot of the testers that have been floating around eBay for a while. There was a pretty long thread about them a while back if I remember right. I have one that's just an LCD display stacked on a board with the microcontroller (Atmel I think) with no case and I've never had any problems with it. You should probably contact the seller.

[andy-h-h]

So I bought one of these, and I compared it to the RG Keen method, and I'm getting very different leakage results.   What am I doing wrong??? hFE looks close enough, leakage is quite different.

Testing an OC75, using  bench power supply, 9v and a digital multi-meter

RG Keen method
First reading = 1.3v
Second reading =  2v
1.3 / 2.472 = 0.526mA leakage
(2 - 1.3) * 100 = hFE 70

Multi-function tester
hFE = 73
Ube = 109mV
Ic = 1.2mA
Iceo = 0.45m
Ices = 31uA

EDIT / UPDATE.   I think I found the answer, but still have to work out how to apply it.  relates to different test conditions.   


from ELECTRIP post - link here.   http://www.diystompboxes.com/smfforum/index.php?topic=108294.msg986737#msg986737

To compare different component analysers one has to know the test conditions of every parameter tested.
hfe is dependent on Ic (and Uce),
Uf is dependent on If
C_reverse is dependent on U_reverse

Example (OC75 @ 27.0°C)
DCA75pro Test Result:

PNP Germanium BJT
Red-C Green-B Blue-E
HFE=78 at Ic=5,01mA
Vbe=0,370V at Ib=5,00mA
IcLeak=0,377mA   

MK-168 fw1.10k Test Result:
PNP
B=69
Uf=177mV
ICE0=0.37mA
ICEs=0.02mA

Lower B/HFE  and Uf/Vbe readings indicate a lower Ic/If for measurement
Now one could check the R.G. Keen-method against it
which actually tests at different Ic's depending on the transistor HFE.

[PRR]

> HFE=78
> IcLeak=0,377mA   
>--------------
> B=69
> ICE0=0.37mA

These look mighty similar?

[andy-h-h]

Thanks for responding Paul.  Unfortunately the matching values are from someone else's post. 

I think the issue is that my tester runs off a 4v rechargeable battery, and it does not specify the test conditions.  Leakage is off by as much as 50% quite frequently, but the hFE is usually very close.   

RG Keen method
First reading = 1.3v
Second reading =  2v
1.3 / 2.472 = 0.526mA leakage
(2 - 1.3) * 100 = hFE 70

Multi-function tester
hFE = 73
Ube = 109mV
Ic = 1.2mA
Iceo = 0.45m
Ices = 31uA

[PRR]

> from someone else's post. 

Ah, yes, sorry, fingers fumble.

RG Keen method
0.526mA leakage
hFE 70

Multi-function tester
Iceo = 0.45m
hFE = 73

[Big Monk]

Thanks for responding Paul.  Unfortunately the matching values are from someone else's post. 

I think the issue is that my tester runs off a 4v rechargeable battery, and it does not specify the test conditions.  Leakage is off by as much as 50% quite frequently, but the hFE is usually very close.   

RG Keen method
First reading = 1.3v
Second reading =  2v
1.3 / 2.472 = 0.526mA leakage
(2 - 1.3) * 100 = hFE 70

Multi-function tester
hFE = 73
Ube = 109mV
Ic = 1.2mA
Iceo = 0.45m
Ices = 31uA

I guess the thing to remember would be that in instances where we want to use Germanium transistors, we need either high or low leakage devices. The draw of a tester like this is the "plug and chug" functionality for roughly sort transistors for specific purposes.

For instance, if I want to make a Tone Bender MkII, I wouldn't be all that interested in EXACT gains and leakages but rather the ability to roughly sort 10-12 transistors very quickly with no extra math. All I need to know is approximate gain and that they leak considerably, not exact values.

Conversely, if I want to build a FF or Rangemaster, and I was fairly confident in the hFE values I was getting, I'd be content with rough sorting for the lowest leakages you could find, again without any extra math or fiddling.

I think you've talked (or I've talked) me into buying one of these!

[andy-h-h]

Thanks for responding Paul.  Unfortunately the matching values are from someone else's post. 

I think the issue is that my tester runs off a 4v rechargeable battery, and it does not specify the test conditions.  Leakage is off by as much as 50% quite frequently, but the hFE is usually very close.   

RG Keen method
First reading = 1.3v
Second reading =  2v
1.3 / 2.472 = 0.526mA leakage
(2 - 1.3) * 100 = hFE 70

Multi-function tester
hFE = 73
Ube = 109mV
Ic = 1.2mA
Iceo = 0.45m
Ices = 31uA

I guess the thing to remember would be that in instances where we want to use Germanium transistors, we need either high or low leakage devices. The draw of a tester like this is the "plug and chug" functionality for roughly sort transistors for specific purposes.

For instance, if I want to make a Tone Bender MkII, I wouldn't be all that interested in EXACT gains and leakages but rather the ability to roughly sort 10-12 transistors very quickly with no extra math. All I need to know is approximate gain and that they leak considerably, not exact values.

Conversely, if I want to build a FF or Rangemaster, and I was fairly confident in the hFE values I was getting, I'd be content with rough sorting for the lowest leakages you could find, again without any extra math or fiddling.

I think you've talked (or I've talked) me into buying one of these!

Definitely - agree with you on this re quick sorting.      You can easily tell if it doesn't leak much, or if it leaks a lot.   What's bothering me is that I need to understand why there's differences in measurements between the two methods, and I don't know this at present. 

It's a very handy little unit, great for dropping random transistors / JETS etc in to find out more about them in a matter of seconds.  Despite the annoyance re differing leakage measurements, for the price it's pretty cool.   

[Big Monk]

Thanks for responding Paul.  Unfortunately the matching values are from someone else's post. 

I think the issue is that my tester runs off a 4v rechargeable battery, and it does not specify the test conditions.  Leakage is off by as much as 50% quite frequently, but the hFE is usually very close.   

RG Keen method
First reading = 1.3v
Second reading =  2v
1.3 / 2.472 = 0.526mA leakage
(2 - 1.3) * 100 = hFE 70

Multi-function tester
hFE = 73
Ube = 109mV
Ic = 1.2mA
Iceo = 0.45m
Ices = 31uA

I guess the thing to remember would be that in instances where we want to use Germanium transistors, we need either high or low leakage devices. The draw of a tester like this is the "plug and chug" functionality for roughly sort transistors for specific purposes.

For instance, if I want to make a Tone Bender MkII, I wouldn't be all that interested in EXACT gains and leakages but rather the ability to roughly sort 10-12 transistors very quickly with no extra math. All I need to know is approximate gain and that they leak considerably, not exact values.

Conversely, if I want to build a FF or Rangemaster, and I was fairly confident in the hFE values I was getting, I'd be content with rough sorting for the lowest leakages you could find, again without any extra math or fiddling.

I think you've talked (or I've talked) me into buying one of these!

Definitely - agree with you on this re quick sorting.      You can easily tell if it doesn't leak much, or if it leaks a lot.   What's bothering me is that I need to understand why there's differences in measurements between the two methods, and I don't know this at present. 

It's a very handy little unit, great for dropping random transistors / JETS etc in to find out more about them in a matter of seconds.  Despite the annoyance re differing leakage measurements, for the price it's pretty cool.

I guess my point is that leakage is useful in ranges. I don't think it benefits you to know exactly where a difference of 100 microamps of leakage is coming from.

If you did need to know, I imagine the test voltage  and internal resistance of the tester is to blame, i.e. they differ marginally from the RG test set. I would imagine back calculating from the data you have would be very simple.

[Big Monk]

Thanks for responding Paul.  Unfortunately the matching values are from someone else's post. 

I think the issue is that my tester runs off a 4v rechargeable battery, and it does not specify the test conditions.  Leakage is off by as much as 50% quite frequently, but the hFE is usually very close.   

RG Keen method
First reading = 1.3v
Second reading =  2v
1.3 / 2.472 = 0.526mA leakage
(2 - 1.3) * 100 = hFE 70

Multi-function tester
hFE = 73
Ube = 109mV
Ic = 1.2mA
Iceo = 0.45m
Ices = 31uA

I guess the thing to remember would be that in instances where we want to use Germanium transistors, we need either high or low leakage devices. The draw of a tester like this is the "plug and chug" functionality for roughly sort transistors for specific purposes.

For instance, if I want to make a Tone Bender MkII, I wouldn't be all that interested in EXACT gains and leakages but rather the ability to roughly sort 10-12 transistors very quickly with no extra math. All I need to know is approximate gain and that they leak considerably, not exact values.

Conversely, if I want to build a FF or Rangemaster, and I was fairly confident in the hFE values I was getting, I'd be content with rough sorting for the lowest leakages you could find, again without any extra math or fiddling.

I think you've talked (or I've talked) me into buying one of these!

Definitely - agree with you on this re quick sorting.      You can easily tell if it doesn't leak much, or if it leaks a lot.   What's bothering me is that I need to understand why there's differences in measurements between the two methods, and I don't know this at present. 

It's a very handy little unit, great for dropping random transistors / JETS etc in to find out more about them in a matter of seconds.  Despite the annoyance re differing leakage measurements, for the price it's pretty cool.

Inspired by this thread, I picked up a TC1 tester. It came yesterday and i had a prime candidate for measurement in a leftover Q1 from a Small Bear Tonebender MKII set.

Steve measure 63 hFE and 21 microamps of leakage using the "Bare Bones" method. the TC1 measures it at 63 hFE and 14 microamps of leakage. Not bad!

As to why the difference, i'm not 100% sure. There is of course the question of differing voltages. I know that Steve measures at ~ 9vDC, as well as R.G. test rig. My TC1 is around 4.15 vdc on a full charge. There is also the question of internal resistances for TC1 playing a role in the measurements.

Lastly, we have to factor in environmental conditions. I  know that Steve from Small Bear advocates letting the reading stabilize in his measurement documentation for the "Bare Bones" method, but you never know how much he had to contact a transistor when testing a number of devices in a row. I for one saw a decrease down to 8 microamps leakage from 14 after letting my device "settle" in the TC1 for a few minutes.

Keep in mind that the margin of error for lower leakage transistors will be higher just due to the low leakage anyway, i.e. the difference between 21 and 14 microamps in my case (33%) is MUCH greater than the one you saw for 526 and 450 microamps (15%). At the end of the day, mostly anything under 100 microamps is good enough for me as "low" leakage and if I need anything "high" leakage, knowing that it is "high" from a ballpark value is really all I need.

The moral: This TC1 unit seems to hit gains on the head and there is really no value in knowing EXACT leakage, so this thing is a godsend.

[soggybag]

If I understand correctly, the "Iceo" is the leakage? What is "ube", "Ic", and "Ices"? 

[soggybag]

I measured a bag of Ge transistors I got from eBay. I measured these using the R.G. Keen method and wrote the Hfe on each. When I measure these with the TC-1 I get roughly half the Hfe? Did I make a mistake somewhere or would this have something to do with the difference in operating voltage of the TC-1?

[Rob Strand]

If I understand correctly, the "Iceo" is the leakage? What is "ube", "Ic", and "Ices"?

Ic = collector current for hFE test
ube = Vbe = base emitter voltage;  usually given when operating at Ic

Iceo = leakage from collector to emitter with base open.   
           This is what RG's jig measures as the base is open.
Ices = leakage from collector to emitter with base shorted to emitter.
You will also see,
Icbo = leakage from collector to base with emitter open.
       
Ices and Icbo should be in the same ball-park. 

Iceo is much larger.     The leakage current Icbo acts like a base current inside the transistor.
The base current gets multiplied by hFE to produce a collector current of hFE * Icbo.
So the collector emitter current you measure is Iceo = (hFE+1)*Icbo.
Since hFE is large Iceo is somewhat larger than Icbo.

I measured a bag of Ge transistors I got from eBay. I measured these using the R.G. Keen method and wrote the Hfe on each. When I measure these with the TC-1 I get roughly half the Hfe? Did I make a mistake somewhere or would this have something to do with the difference in operating voltage of the TC-1?

Did you remove the leakage from Ic when you calculated the hFE?   If you don't remove the leakage you end up with larger hFE.   IIRC, with RG's jig you subtract the leakage number from the hFE measurement.

Next on the list would be the leakage is wandering due to temperature perhaps heating from your fingers.  If you are touching the part  or pins it can also cause weird measurements.

Try a silicon transistor on both test jigs and make sure the hFE numbers agree.   That will remove any disagreement due to leakage.

EDIT:
FWIW, what is the IC reported on the TC1 and what voltages are you seeing on RG's jig?    If the test currents are widely different you could see a difference in hFE.    Usually low test currents show lower hFE.  Check with a germanium and silicon transistor.

[Electron Tornado]

I have one of these as well as one that is just a circuit board and a clear plastic frame as an "enclosure". Both seem to work well. Regarding the one you have, make sure the battery is charged when you test.

I tested several transistors with one of those testers as well as R.G. Keen's method. The results were consistently very close.

[soggybag]

I measured a bag of AC128 transistors using the TC1. If anyone has a couple minutes to help me make sense of the numbers and identify some candidates for a couple Fuzz Faces and a Tone Bender that would be awesome!

Heres a link to the spread sheet.

https://docs.google.com/spreadsheets/d/10O7FYfs_f0x301CYvcvC7pWFFp8Ld2-e3oANXK-AOtc

If there's some math involved tell what it is and I can add a formula.