This electronic component tester circuit is like a doctor for your electronics stuff.
Before you build something cool, you can use this tester to check parts like resistors, capacitors, transistors and more.
The tester tells you if they are working properly, so you do not waste time using broken parts in your project.
This is especially helpful for hobbyists and people who like to tinker with electronics.
Circuit Working:
Parts List:
| Category | Component | Quantity | Details |
|---|---|---|---|
| Resistors | 4.7k | 1 | 1/4 watt |
| 1.8k | 1 | 1/4 watt | |
| 1.2k | 1 | 1/4 watt | |
| Capacitor | Ceramic C1 0.1µF | 1 | |
| Semiconductors | Transistor BC547 | 2 | |
| Diodes 1N4148 | 2 | ||
| LEDs | Green LED (5mm, 20mA) | 1 | |
| Red LED (5mm, 20mA) | 1 | ||
| Other | Red Meter Probe | 1 | |
| Black Meter Probe | 1 | ||
| Power Source | Battery 9V | 1 |
This device is designed to verify the integrity of electronic components ranging from resistors to ICs prior to soldering, streamlining the testing process typically done with a multimeter.
Through LED indicators it promptly signals whether the tested components are in good or bad condition.
The circuit design is simple yet effective.
Utilizing two bipolar NPN transistors it drives two LEDs based on their base bias.
Upon powering up, the Red LED illuminates as T2 receives base bias through R2 while the green LED remains inactive with T1s base floating.
When a component is positioned between the probes electrical continuity is established, causing T1 to receive base current via R1.
As T1 conducts, the Green LED illuminates and the Red LED extinguishes, as T2s base is grounded during T1s conduction.
This indicates the satisfactory condition of the tested component.
In essence, the green LED only lights up when a functioning component is connected to the probes.
Conversely, if the component is faulty, there will be no electrical continuity and T1 will remain inactive resulting in the red LED alone illuminating to signify a defective component.
Formulas:
Using the above mentioned components you will build a simple circuit that can test resistors, LEDs and maybe other basic components in order to make an electrical component tester circuit.
The following design employs LEDs to show the tested components state and a transistor as a simple switch.
Current Passing thru the LED:
Apply ohms law to make sure the LED gets the right amount of current:
ILED = VBattery−VLED / R
where,
- VBattery is 9V
- VLED is 2V (forward voltage drop)
- R is the resistor
Switching Transistors:
Make sure there is enough base current IB to saturate the transistor:
IB = VBase−VBE / RBase
where,
- VBase is 9V
- VBE is 0.7V (base-emitter voltage)
Current Passing Through Resistors:
Use ohms law to determine the current flowing through the resistors.
IR = VBattery / R
LEDs and resistors may be tested using this easy to assemble circuit.
The LEDs, which show the condition of the components under test, are controlled by the two BC547 transistors, which function as switches.
The circuit is protected and operates properly thanks to the resistors and diodes. If necessary, change the resistor values according to the specifications or component ratings.
How to Build:
Below mentioned are the process to build a Simple Electronic Component Tester Circuit:
Connect the Components:
- Start by placing the components on the breadboard or PCB according to the circuit diagram.
Connect the Power Supply:
- Connect the positive terminal of the 9V power supply to the circuit and the negative terminal to the ground of the circuit.
Test LED Indications:
- Apply power and test the LEDs.
- The red LED should light up to indicate power, and the green LED should be off initially.
Calibration (Optional):
- If you have a potentiometer, adjust it until the green LED just starts to light up indicating a good component when the probes are not connected to any component.
Testing Components:
- To test a component, connect its leads to the probes.
- The green LED should light up if the component is good and the red LED should light up if the component is bad.
Final Testing:
- Once you are satisfied with the circuits performance, you can use it to test various electronic components before soldering them into your projects.
Note:
- This is a basic circuit design.
- Depending on your requirements, you may need to add additional features or modify the circuit to suit your needs.
Conclusion:
In conclusion, an electronic component tester circuit is a valuable tool for hobbyists and electronics enthusiasts, allowing them to quickly and easily test the integrity of various components before integrating them into their projects.
By following a simple design and using basic components such a tester can help ensure the reliability and functionality of electronic components, ultimately saving time and effort in troubleshooting and circuit debugging.