24-04-2022, 10:27 AM
I have got an old home made tester with five collector current settings and a crude leakage setting.
It uses a fixed Vce with a metal cased 741 to sense Vce at 5 volts and a pot and meter on the base.
HFE was found using a pencil and paper and later a pocket calculator.
Last time I used it I fed the collector current from a bench power supply with the DUT on a heat sink going much higher than it was from the start.
The original aim was to start making my own data sheets for unknown transistors that used to be on sale in bulk bags and finding matched pairs.
It uses a fixed Vce with a metal cased 741 to sense Vce at 5 volts and a pot and meter on the base.
HFE was found using a pencil and paper and later a pocket calculator.
Last time I used it I fed the collector current from a bench power supply with the DUT on a heat sink going much higher than it was from the start.
The original aim was to start making my own data sheets for unknown transistors that used to be on sale in bulk bags and finding matched pairs.
