Further to an earlier post where I commented on the component tester I found some more information about them and just put mine into an enclosure.
I bought a few desktop console enclosures a while back. Not much needed done just extend the display, add some better terminals and a button.
This was a photo of how it had been done elsewhere:
I'll post photos of mine here.
Some more detail of it are here:
Designed originally by Markus Frejek, and pimped out by Karl Kubbler with some cool software mods, this inexpensive little board does some wondrous measurements!
Manual available as “ttester.pdf” in files section of qrp-tech or HERE
Series of manuals and software for original design and upgrades can be found at http://www.mikrocontroller.net/articles/AVR_Transistortester
Beware of similar items as not all of them are the latest version with resistor matching function and ESR testing ability.
Tests resistors, capacitors above 1000 pF, inductors above 10 uH, and many semiconductors and most importantly ESR of capacitors above 10 uF.
Very handy for bench testing, matching audio and power inductors and capacitors, identifying semiconductor pinouts and characteristics. Not suitable for most RF inductors and capacitors.
1. Operates with ATmega8, ATmega168 or ATmega328 microcontrollers.
2. Displaying the results to a 2x16 character LCD-Display.
3. One key operation with automatic power shutdown.
4. Battery operation is possible since shutdown current is only about 20nA.
5. Low cost version is feasible without crystal and auto power off. With software version 1.05k
the sleep modus of the Atmega168 or ATmega328 is used to reduce current if no measurement
6. Automatic detection of NPN and PNP bipolar transistors, N- and P-Channel MOSFETs,
JFETs, diodes, double diodes, Thyristors and Triacs.
7. Automatic detection of pin layout of the detected part.
8. Measuring of current amplifcation factor and Base-Emitter threshold voltage of bipolar transistors.
9. Darlington transistors can be identifed by the threshold voltage and high current amplifcation
10. Detection of the protection diode of bipolar transistors and MOSFETs.
11. Measuring of the Gate threshold voltage and Gate capacity value of MOSFETs.
12. Up to two Resistors are measured and shown with symbols and values with up to four
decimal digits in the right dimension. All symbols are surrounded by the probe numbers of the
Tester (1-3). So Potentiometer can also be measured. If the Potentiometer is adjusted to one
of its ends, the Tester cannot di er the middle pin and the end pin.
13. Resolution of resistor measurement is now 0:1, values up to 50M are detected.
14. One capacitor can be detected and measured. It is shown with symbol and value with up
to four decimal digits in the right dimension. The value can be from 25pF (8MHz clock, 50pF
@1MHz clock) to 100mF. The resolution can be up to 1 pF (@8MHz clock].
15. For capacitors with a capacity value above 2 F the Equivalent Serial Resistance (ESR) is
measured with a resolution of 0:01
and shown with two signi cant decimal digits. This feature
is only avaiable for ATmega with at least 16K ash memory (ATmega168 or ATmega328).
16. Up to two diodes are shown with symbol or symbol in correct order. Additionally
the ux voltages are shown.
17. LED is detected as diode, the ux voltage is much higher than normal. Two-in-one LEDs are
also detected as two diodes.
18. Zener-Diodes can be detected, if reverse break down Voltage is below 4.5V. These are shown as
two diodes, you can identify this part only by the voltages. The outer probe numbers, which
surround the diode symbols, are identical in this case. You can identify the real Anode of the
diode only by the one with break down (threshold) Voltage nearby 700mV!
19. If more than 3 diode type parts are detected, the number of founded diodes is shown additionally
to the fail message. This can only happen, if Diodes are attached to all three probes and at
least one is a Z-Diode. In this case you should only connect two probes and start measurement
again, one after the other.
20. Measurement of the capacity value of a single diode in reverse direction. Bipolar Transistors
can also be analysed, if you connect the Base and only one of Collector or Emitter.
21. Only one measurement is needed to nd out the connections of a bridge rectifier.
22. Capacitors with value below 25pF are usually not detected, but can be measured together with
a parallel diode or a parallel capacitor with at least 25pF. In this case you must subtract the
capacity value of the parallel connected part.
23. For resistors below 2100
also the measurement of inductance will be done, if your ATmega
has at least 16K ash memory. The range will be from about 0:01mH to more than 20H,
but the accuracy is not good. The measurement result is only shown with a single component
24. Testing time is about two seconds, only capacity or inductance measurement can cause longer
25. Software can be configured to enable series of measurements before power will be shut down.
26. Build in self test function with optional 50Hz Frequency generator to check the accuracy of
clock frequency and wait calls (ATmega168 and ATmega328 only).
27. Selectable facility to calibrate the internal port resistance of port output and the zero o set
of capacity measurement with the self test (ATmega168 and ATmega328 only). A external
capacitor with a value between 100nF and 20 F connected to pin 1 and pin 3 is necessary to
compensate the o set voltage of the analog comparator. This can reduce measurement errors
of capacitors of up to 40 F . With the same capacitor a correction voltage to the internal
reference voltage is found to adjust the gain for ADC measuring with the internal reference.