Repairing Induction Cooker Main Board and Most Common Problems With Power

 

Let see a high level Component diagram of a Induction cooker

Behind this heat sink of above image there will be IGBT Transsistor and Bridge rectifier Diode (Lets see them in detail in the component repair section)

The main problems facing electric oven users are as follows:

• Blown fuse- occurs due to voltage jump. The low price of new fuses and a simple replacement process make it easy to fix this fault yourself. For the future, we propose to purchase a device that will protect the electrical network from electrical surges.

• Short Circuit with Bridge Rectifier Diode- This can trigger the Fuse to blown if the AC line of the Bridge Rectifier is short.
  
  
  
  Have you heard of a bridge rectifier? In case you didn’t know, a bridge rectifier, also called a full bridge rectifier, is a set of four or more diodes in a bridge circuit configuration. It gives the same output polarity to either input polarity or is utilized for converting an AC input into a DC input.
  
  

How Do You Test a Bridge Rectifier?

1. Prepare your multimeter (DMM) for the diode check. Insert the probes into the digital multimeter.
2. Please turn on your digital multimeter and set it into a diode-tester function, as guided by the instructions for your certain model.
3. Test the AC inputs. Touch one probe leads to one of the AC inputs, and the other leads to the other input. The multimeter normally suggests an overload. That means there’s too much resistance to measure.
4. Swap the leads at the inputs and repeat the procedure. Any numerical reading suggests that a diode is leaking current in the reverse-biased course.
5. Test your individual diodes. Put the positive lead to an AC input, and the negative probe lead to the positive output. See the reading. Swap the leads and check the reading on the meter display. Do the same process again for the other AC input.
6. Take note that a successful check shows that one diode conducts within the forward-biased direction, shown on the meter as turn-on voltage of at least 0.7 volts.
7. Do the same process between the negative output and the AC inputs. Disconnect the leads and turn off the multimeter.
8. For the last step, check whether the bridge rectifier is usable or not. If every diode passes that check test, then it means your bridge rectifier is good to use. But even if one diode leaks, you should replace it right away.

• Short Circuit with IGBT Transistor

An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily used as an electronic switch which, as it was developed, came to combine high efficiency and fast switching. It is a three-terminal semiconductor device, those pin are labeled collector(C), gate(G) and emitter(E). now, i will show how to check transistor using multimeter. The high voltage applications like PWM, SMPS, variable speed control, AC to DC converter powered by solar and frequency converter applications which operates with a hundred’s of KHz.

How Do You Test a IGBT Transistor ?

 

• First turn ON digital multimeter and select continuity mode.
• Connect the test leads to the IGBT terminals. Keep test leads connected for a few seconds at like this (A) connection.
• if multimeter buzzer is ON, the IGBT is bad(damage) conditions.

• Connect the test leads to the IGBT terminals. Keep test leads connected for a few seconds at like this (B) connection. 
• if multimeter buzzer is OFF, the IGBT is good conditions.
  
  Image Courtesy :
  leetsacademy.blogspot.com
  
  What caused this IGBT failure?
  
  http://www.sorotecups.com/causes-solutions-igbt-damage/
  
  
  https://electronics.stackexchange.com/questions/86388/what-caused-this-igbt-failure
  
  
  I will explain about more failures and about the components such as filter capacitor and microcontroller in part II.