using AT ATmega328 microcontroller.
2x16 character LCD display results.
one-button operation, automatic power off.
shutdown current of only 20nA, support for battery operation.
low-cost version without the crystal, auto power off. 1.05k version of the software ATmega168 or ATmega328 in sleep mode when no measurement to reduce power consumption.
Automatic detection PNP and NPN bipolar transistor, N, P-channel MOSFET, JFET, diodes, dual diode, thyristor SCR.
automatically detects the pin layout.
the threshold voltage and current amplification factor of the emitter junction of the bipolar transistor measurements.
Darlington transistor through a high threshold voltage and high-current amplification factor identified.
pairs of bipolar transistors, MOSFET protection diode testing.
The threshold voltage value 11 and the gate capacitance of a MOSFET is measured.
Supports two resistance measurements and symbols show the highest four numbers and units. Both ends of the resistor symbol is shown connected to the tester probes number (1-3). Therefore, the potential can also be measured. If the potentiometer is adjusted to its end, the tester can not distinguish between the middle and the ends of the pin.
resistance measurement resolution is 0.1 ohms, the highest measured value 50M ohms.
can be detected and measured a capacitor. Maximum four numbers and units. Values can be from 25pf (8MHz clock, 50pF @ 1MHz clock) to 100mF. Resolution up to 1 pF (@ 8MHz clock).
may be larger than the value for 2UF capacitor equivalent series resistance (ESR) measured capacitance value. Resolution of 0.01 ohms and a two-digit numeric display. This feature requires at least 16K Flash ATMEGA (ATmega168 or ATmega328).
can display symbols of the two diodes in the right direction. In addition, the forward voltage drop displayed.
LED detection for diode forward voltage drop is much higher than normal. Dual LEDs detected as double diode.
Zener diode 18 can be detected, if the reverse breakdown voltage is less than 4.5V. This will appear as two diodes, can only be determined by the voltage. Probe around the diode symbol is the same, in which case, you can 700mV threshold voltage close to the true recognition diode anode!
If more than three diode type parts inspection, failure to establish the number of diodes another message. This will only happen if the diode is connected to all three probes and at least one diode. In this case, you should only connect the two probes and start measuring again, one by one.
measures a single diode reverse capacitance values. Bipolar transistors also can measure, if you connect the base and collector or emitter.
need to find a measurement of the full-bridge connection.
25pf capacitor values lower than 22 are usually undetectable, but with a diode in parallel or at least 25pf capacitor in parallel. In this case, you have to subtract part shunt capacitance values.
ohm resistor will measure inductance of less than 2100, if you have at least 16K ATMEGA flash. Range from 0: 01mH than 20H, but the accuracy is not good. Measurement results show only a single connection element.
test time is about two seconds, only the capacitance and inductance measurements will take longer.
software can be set to automatically turn off the power to measure the number of times before.
built-in self-test function with selectable clock frequency of 50Hz signal check the accuracy and wait for the call (ATmega168 and ATmega328).
optional resistance and zero offset calibration of measuring equipment self-test capability of the port output (ATmega168 and ATmega328). Need a 100nF to 20uF capacitor connected to compensate the analog comparator between pins 1 and 3 of the offset voltage. This can reduce the measurement error 40uF above capacitor. With the same internal calibration capacitor voltage reference voltage is found to internal adjustment reference measurement ADC gain.
If the test current exceeds the holding current, the thyristor and triac can be detected. But some current higher than the semiconductor SCR and triac tester can provide the trigger current. Available test current is only about 6mA! Note that all functions have only used single-chip program memory as more ATmega168.