My Fundamental Circuit Board Learning
I was curious about the significance of the letters on the board, aiming to grasp how it functions. Consequently, I chose to create this resources to refresh my understanding of circuit boards, in case I've forgotten some details.
Acronyms of boards
The following is the meaning of some letters on the PCB board:
- B: buzzer
- C: capacitor
- D: diode
- F: fuse
- L: inductor
- Q：Triode
- R：resistor
- RT：Thermistor
- T：transformer
- Y：crystaloscillator
R107, C118, Q102, D202 and other numbers are often seen on circuit boards. Generally, the first letter identifies the device category, such as R for resistors, C for capacitors, D for diodes, and Q for Triode, etc.; The second is a number, indicating the circuit function number, such as "1" for the main board circuit, "2" for the power supply circuit, etc., which is determined by the circuit designer; the third and fourth digits indicate that the device is on the circuit board The serial number of similar devices.
Testing on Multimeter
In this section we're going to learn how to use Multimeter.
Resistance
Make sure Test Leads are connected and desginated Black: COM and Red: VΩmA.
Remember Resistance = Ohm's and here is the following range:
- 200: < 200 Ω
- 2,000: < 2,000 Ω
- 20,000: < 20,000 Ω
- 200,000: < 200,000 Ω
- 2,000,000: < 2,000,000 Ω
- 20,000,000: < 20,000,000 Ω
Materials that under resistance:
- Resistor: Make sure check the resistance by color code. You can use Resistor Color Code Calculator
- Incandescent Bulb
- Fuse
Continuity Test
If you want to quick test, you can use Continuity Test the symbol looks like soundwave.
Diode Test
If you want to test diodes, you can use Diode Test the symbol looks like Arrow that pointed to vertical line.
Materials that can be test:
- Diode
- LED: Emit light
Voltage
Make sure Test Leads are connected and desginated Black: COM and Red: VΩmA. Wear Safety Gloves.
Difference types of voltage: Alternating Current (AC) and Direct Current (DC)
- “V” with a wavy line over it: AC voltage
- “V” with one dotted and one solid over it: DC voltage
- 20: < 20 V~
- 200: < 200 V~
- 600: < 600 V~
AC Materials that can be test:
- Outlet
- Transformer
- AC Generators
Recomended to test only with one hand to avoid discharge from outlet and wear Safety gloves!
DC Materials that can be test:
- AA Battery or any battery
- 3v Battery: like watch battery
- Solar Panel
Amphere
Make sure Test Leads are connected and desginated Black: COM and Red: 10A.
After testing amphere, make sure your Test Lead Red is connected to VΩmA
Safety for multimeter
- Add rubber case.
- Maintain normal switching test: to avoid malfunctioning.
- If low battery make sure change the battery to have better reading.