The "Transistortester" component tester or LCR-TC1

Last modified 4 weeks

The LCR-TC1 meter is a simply amazing device. I couldn't live without it (well, yes, but my life would be a bit harder). It is a device a must-have for the electronics enthusiast.

This device allows us to connect any of the components that we usually use in our electronics projects, and AUTOMATICALLY will identify the component and tell us everything we need to know about it.

Can you imagine the convenience of simply putting any component in the meter and having it identify whether it is an NPN transistor, a PNP transistor, an N-channel or P-channel MOSFET, a JFET, a diode, a thyristor, a triac, a resistor, a capacitor, a coil, etc.?

Y not only identifies the componentbut:

ESR measurement

A great thing about this meter is that it doesn't just do the measurement we tell it to do, it automatically identifies the component we connect to it, and CHARACTERISE IT (i.e. give us together and at the same time all parameters that define a component and differentiate it from another of the same type).

Key features of the LCR-TC1 meter

Resistance Measurement

The TC-1 allows you to measure resistors with high accuracy. It can determine the resistance value of a component, which is essential for verifying whether a resistor is within the required specifications for a given circuit. This is vital to ensure that a circuit is working properly and to identify faulty components.

Capacitance Measurement

This meter is capable of measuring the capacitance of capacitors. Capacitance is a fundamental property in electronic circuits, and the TC-1 allows the integrity of capacitors to be verified, identifying whether they are in good condition or if they are faulty.

ESR (Equivalent Series Resistance) Measurement

It measures not only the capacitance, or capacitance, of the capacitors, but also their ERS or Equivalent Series Resistance (click here if you want to know what is the ESR).

Inductance Measurement

The TC-1 can also measure the inductance of inductors. Inductance is important in applications such as switching power supplies and filter circuits. With this functionality, it is possible to determine if an inductor is working properly or if it needs to be replaced.

Continuity Test

A key function of the TC-1 meter is the continuity test. It can identify if there is a continuous electrical connection in a circuit or between two specific points. This feature is crucial for locating short circuits and verifying the integrity of PCB (printed circuit board) traces.

Frequency Measurement

The TC-1 is capable of measuring the frequency of electrical signals. This is useful in applications where the frequency of a signal is critical, such as in communication and control systems. The ability to measure frequencies makes it possible to ensure that signals are within the required parameters.

Temperature Measurement (Optional)

Some TC-1 meter models offer the ability to measure temperature. This is useful in applications where temperature is a critical factor, such as in the design and testing of temperature control circuits or thermal management systems.


The TC-1 meter often features self-calibration capability, which ensures accurate measurements and avoids the need for frequent manual calibrations. This saves time and ensures reliable measurements.

High Contrast LCD Display

The TC-1's high-resolution, high-contrast LCD display makes it easy to read measurement results even in adverse lighting conditions.

Infrared decoding

The LCR-TC1 meter has a built-in infrared decoder. Simply select this function, point the remote control at the meter to decode and press a button. The meter will tell us the transmitted code and show us a visual representation of the signal.

Buy the LCR-TC1 Component Meter

There are many versions of this meter so I recommend that you have be careful which one you buy and where.


My LCR-TC1 meter

This is my meter. I bought it in 2019 and it is still working great. At the moment it costs less than 14€ on AliExpress and, in Spain, it is delivered in 5 days.

Some versions are very nice, with nice menus and colours, but they leave a lot to be desired. Apparently the main problem with these versions is that they have been ported to a different any case"I recommend that you buy the LCR-TC1, which is a model that has been around for many years and works very well. I recommend that you buy the LCR-TC1 component tester, which is a model that has been around for many years and works very well.

You can also buy it on Amazon and you will get it at home quickly. This seller has more than 1200 ratings and a 4.4 star rating:

diymore LCR TC1 ESR Tester Transistor Inductance Resistance Capacitance ESR Meter Multifunctional TFT Tester LCR-TC1 Transistor for Transistor
  • Multifunction tester: to detect NPN and PNP transistors, capacitors, resistors, diodes, triodes, N and MOSFET with P-channel, JFET, IGBT, Triac and battery, resistor and capacitor and other components, etc.
  • TFT graphic display (160 x 128): detector to insert the component pins into the area, then the small handle and the corresponding one to be tested automatically, at the end the results are displayed on the back of the transparent TFT display. Compatible with Chinese and English.
  • 【IR decoder】: after detection, align the infrared remote control with the "IR" light, then press the button on the remote control, if the detector successfully decodes, the data code and infrared waveform are displayed.
  • LED charging indicator: if the black screen may be out of power, fully charge the device to test. When charging, the charging indicator will be light red, and when full, it will be light green. Reminder: the charging input voltage is 4.5V, please do not use the ESR TC1 transistor tester under over-pressure, otherwise the tester will be damaged.
  • Automatic calibration: three short-circuit test sockets, short press the multifunction button, the tester will calibrate automatically. After disconnecting the short circuit according to the message during the calibration process, no further operations are required (if you have any questions, please feel free to contact us).

Don't buy just any meter

For example, I also have a similar tester, the Fish8840 AVR Transistor Tester, based on the same open source project, and it has nothing to do with it. The LCR-TC1 is much better.

Technical details of the LCR-TC1 meter

The TC1 meter, like others like it, is based on the TC1 project. open source "AVR Transistortester" by Markus Frejek, improved and maintained by Karl-Heinz Kübbeler.

It's amazing what this pair of geniuses have achieved...

That is all that makes this project "magical":

  • Works with ATmega8, ATmega168, ATmega328 or ATmega644 and ATmega1284 processors.
  • Displays the results on an LCD screen of 2×16 o 4×20 characters. It is also possible to a graphic display with the ST7565, NT7108 or ST7920 controller. An OLED display is also possible with the SSD1306 controller and communication via SPI or I2C interface. You can also connect colour displays with ILI9341 or ILI9163 controller.
  • One-button operation with automatic switch-off.
  • Three test pins for universal use.
  • Automated transistor detection NPNPNPchannel MOSFETs NP, JFETdiodes y thyristors small, TRIAC.
  • Automated pin assignment detection, which means that the device under test can be connected to the tester in any order.
  • Measurement of hFE and base-emitter voltage for bipolar junction transistors, also for Darlingtons.
  • Automated detection of protection diodes in bipolar junction transistors and MOSFETs.
  • Bipolar junction transistors are detected as a transistor with a parasitic transistor (NPNp = NPN + PNP parasitic).
  • Up to two resistors with a resolution of up to 0.1 ohms. The measuring range is up to 50 Mohm (Megaohm). Resistances below 10 ohms will be measured with the ESR approach and a resolution of 0.01 ohms if an ATmega168/328 is used. Caution: resolution is not precision.
  • Capacitors in the range of 35 pF (picofarad) to 100 mF (millifarad) can be measured with a resolution of up to 1 pF.
  • If the processor has at least 32K flash memory, you can use the Pieter-Tjerk samplingADC method to obtain a resolution down to 0.01 pF for capacitors with a capacitance of less than 100 pF.
  • Resistors and capacitors shall be shown with their respective symbol, pin number and value.
  • Up to two diodes will also be displayed with their correctly aligned symbol, pin number and voltage drop.
  • In the case of a single diode, the parasitic capacitance and reverse current shall also be measured.
  • For ATmega168/328 a self-calibration of zero capacitance, zero resistance and other parameters is possible.
  • For ATmega168/328 it is also possible to detect and measure inductances from 0.01 mH to 20 H.
  • If your processor has at least 32K flash, you can use the samplingADC method to measure smaller inductances with a parallel capacitor of known capacitance. The resonant frequency and the calculated inductance value are displayed, as well as the quality factor.
  • For ATmega168/328 an ESR (equivalent series resistance) measurement of capacitors greater than 20 nF is incorporated. The resolution is 0.01 ohms. For lower capacitance values, the accuracy of the ESR result worsens.
  • For ATmega168/328 the Vloss of capacitors larger than 5 nF is examined. With this it is possible to estimate their Q-factor.
  • For the ATmega328, you can access a menu function with a long press of the key (> 0.5 s).
  • A short key press switches to the next function. A long press of the button starts the function. The list of functions incorporated so far: Frequency measurement on pin PD4. This pin is also used for the LCD display and will be switched to the input (High-Z) for measurement. The frequency is measured for 1 second. If it is below 25 kHz, the period will be measured to improve the accuracy. The resolution goes down to 0.001 mHz.
  • Voltage measurement on pin PC3, if it is not used for serial output. Since ATmega328 has 32 pins (PLCC), ADC6 or ADC7 can also be used. A 10:1 divider is used, so voltages up to 50 V can be measured. With an additional DC-DC converter, Zener diodes can also be measured.
  • Frequency generation on the TP2 port. A 680 ohm resistor connected to the PB2 pin can be used to generate a 1 Hz to 2 MHz signal on the TP2 port. The TP1 port is grounded.
    Variable PWM (pulse width modulation) with fixed frequency on TP2 port. 10-bit counter. TP1 port is grounded. Short pulse increases pulse width by 1 %, long pulse by 10 %.
  • A separate capacitance and ESR measurement is available. Capacitors from 2 μF to 50 mF can generally be measured in circuit. It must be ensured beforehand that the capacitor is no longer charged.

You have all the information about the project at

Use of the LCR-TC1 meter

In the following article you can see the LCR-TC1 meter in action on video, repairing a power supply (and finding the fault thanks to it):

Leave a comment