measurement

[swaree]

please some one guide me to a site that demonestrate how to measure electronic component as tansistor.

[Kevin Weddle]

I can tell you that you should use two ammeters. You want to keep the ratio the same. Bias the collector current at half the rated maximum current. You probably have a kit that supplies a variable postive and a variable negative. Use this configuration. Vary the input voltage until you get the collector current to 100mA and vary the collector voltage until you can change the voltage and still maintain the ratio. Once you find the voltage you like, then that is your bias voltage.

[audioguru]

Hi Kevin,
You don't need a dual supply to power a transistor. A single supply with a resistive voltage divider for the base will work fine.
Why do you vary the collector voltage? The transistor circuit that you show has the transistor as a constant current sink, therefore changing the collector voltage won't change its current.

Hi Swaree,
Why do you want to measure transistors? You don't trust that new ones are good? I have seen millions of new transistors and have never seen a bad one, just new transistors that don't work because they are installed backwards.
Transistors have many paramanors (current gain, voltage limits, cutoff frequency, etc.). Which ones do you want to measure?