gres
Full Member level 4
This device is a tester for semiconductor elements. An inspiration to built it was article by Markus F. and his prototype of tester, that i found at German web.
Here how we test each element. ( name - indicator on display unit):
NPN transistors - NPN display
PNP transistors - PNP display
N enhanced channel, MOSFET transistor - N-E-MOS display
P enhanced channel, MOSFET transistor - P-E-MOS display
N depleted channel, MOSFET transistor - N-D-MOS display
P depleted channel, MOSFET transistor - P-D-MOS display
N JFET channel - N - JFET display
P JFET channel - P - JFET display
Thyristors- thyristor display
Triacs - triac display
Diodes - Diode display
Double diode , cathode - duodiode WK display
Double diode, anode - duodiode WA display
Two diodes in series connection - two diodes series display
Push-pull connection diodes - push-pull diode display
Resistors - range 0,5k-500k [k]
Condensers - range 0,2nF - 1000uF [nF;uF]
While testing condenser or resistor, result is rough, close to real value. Tester allow to affirm in almost 100% that element R or C is fit.
On the display, except element description we can see:
H21e parameter - range to 10000
Which electrode we have at each socket (1-2-3)
Existence of security diode at the element - diode symbol
Forward voltage - Uf (mV)
Opening gate voltage ( for MOSFET) Vt[mV]
Gate displacement (for MOSFET) - C= [nF]
Except those parameters, tester display communicates:
-testing
- lack or damaged element
- unknown element or damaged
- low battery, too low; battery test indicate low battery (~7,6V) and battery need to be exchanged (~7,15V)
- timeout ; too long time of testing, you need to wait 5 sek and start again.
Brain of construction is microcontroller ATMEGA8, 3 transistors, voltage stabilization 7805 and few diodes , RC elements.
Power supply adaptor or 9 V battery. Tester need about 45 mA while testing. Such big value is because flash diode and display. After 10 seconds device turn to stand by mode.
More at
https://www.elektroda.pl/rtvforum/topic1501377.html
