I installed Arduino IDE 009 since I figured I should learn this stuff if I’m going to sell Arduino’s (and clones)
My project today was to build a simple NPN Hfe (Beta) meter to do some tests on the now ultra-rare 2sc2291 matched pairs. My multimeter has one but I wanted to make sure I was testing with the same setup as the one in the datasheet, with a Vce of about 6V and Ic = 1mA. The results are in the x0xd0x wiki
This is the breadboard circuit I used:
[flickr 1133534664 ]
its similar to the one described on the x0xb0x page, but with the op amp swapped around for NPN’s
The sketch is rather small, I just take the two analog measurements, do a bit of math and spit out the calculated beta. I checked this against my meter and it matched up for lower betas (although not for higher ones, which may mean I’ve got current leaking into the opamp)
[flickr 1132692007 ]
Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground” – Adafruit’s Apps!
Maker Business — Transforming Today’s Bad Jobs into Tomorrow’s Good Jobs
Wearables — Snap a picture
Electronics — To Y5V or not to Y5V?
Biohacking — Ticks are Spreading an Allergy to Meat
No comments yet.
Sorry, the comment form is closed at this time.