IGBT Testing in RnD Labs

Greetings,

A few days back we had posted in our blog some pics and explanation on some High-Power devices. But never had we mentioned that we have put them in test right!!!!!

Today we have tested a High-Power IGBT in the order of 600V, 374A but we shall be utilizing only 60V,200A. Why are we using an IGBT? well, for a secret "X" project for BSNL. The tested voltage is -30V (minus thirty volts). A small picture proof and also a circuit diagram for reference is provided below.

IGBT used: GA200SA60SP (Datasheet: Click Here)

N-Channel MOSFET Testing with Analog Multimeter

The right way of testing an N-Channel MOSFET transistor is to use an Analog Multimeter. First, find out the Gate, Drain and Source from semiconductor replacement book or search its datasheet from search engine.

Once you have the cross reference or diagram for each pin of the MOSFET and your Analogue Multimeter, follow the below instructions:-

1. Set to times 10K ohm range to check it.
2.  Put the Black Probe to the Drain pin.
3.   Touch the Gate pin with the Red Probe to discharge any internal capacitance in the MOSFET.
4. Now move the Red Probe to Source pin while the Black Probe still touching the Drain pin.
5. Use your finger to touch the Gate and Drain pin together. You will notice the Analogue Multimeter pointer will move forward of the meter's scale.

 How to cross-check?

Lifting the Red Probe from the Source pin and putting it back again to the Source pin and the pointer will still remain at the middle of the meter's scale. To discharge it you have to lift the Red Probe and touch just one time on the Gate pin. This will eventually discharge the internal capacitance again.

At this time, use the Red Probe to touch on the Source pin again, the pointer would not kick at all because you have already discharge it by touching the gate pin. 

These are the good MOSFET characteristic. 

If you notice that all the result that you measured kicked towards zero ohms and will not discharge, then the FET is considered shorted and need replacement. Testing the P channel MOSFET is just the same way as when you check N channel MOSFET. What you do is to switch the probe polarity when checking the P channel. Some Analog Multimeter have the times 100k Ohm range, this type of meter can’t really test FET due to the absent of 9 Volt battery inside the Multimeter. This type of meter will not have enough power to trigger the MOSFET. Make sure you use a meter that have the times 10k ohm range selector.

Mega-High-Power Components

Greetings!!!!!!!!!!

We are burning our hands in Power Systems and with outputs in the range of 1K-Watt to 10K-Watt.

In order to work in such high powers, we have work with high Amperes and high Voltages usually in the order of hundred's simply because of the Power Law: P = VI

The main reason for this post to just share information with our readers, followers and well-wishers of the high power components used in the industry. The package of the high power components are called ISOTOP or SOT-227 package. The big black chunk of seen in the below picture is the ISOTOP of the related component. The datasheets are provided below for further information.

Below are a few pictures of the components we are using in our Power Systems.

MOSFET and IGBT - IRF5210, GA200SA60SP and IRF640

Diodes - IN4007, 1N5822 and STTH12003TV

Datasheets:

IRF5219: Click Here
IRF640: Click Here
GA200SA60SP: Click Here

1N4007: Click Here
1N5822: Click Here
STTH12003TV: Click Here
 

Dual Voltage Display (0-20v)

 Hello Everyone,

More developement on Digital Voltmeter Using PIC16F688.

 In previous voltmeter we used to measure only one voltage value.But the voltmeter is modified to diplay two voltages simutaneously.

In modified voltmeter we have assigned pin12 (RA1) as one input and pin11(RA2) as the other input to PIC16F688. The voltage to be measured is fed to one of the 8 analog channels. The reference voltage for AD conversion is chosen to be the supply voltage Vdd (+5 V).A resistor divider network is used at the input end of pin12 and pin11 to map the range of input voltage to the ADC input voltage range (0-5 V).

 Modified Program:Click here

Output

 The  DVM is tested for various input voltages ranging from 0-22 V and some snapshots of the tested DVM are given below.