Normally, transistors are meant to conduct in a particular direction. I have a few that behave differently. As a result, I've come to understand their purpose a bit differently. Although their applications remain the same, there may be more varied use for them than as stated.
Below are a couple of pictures. One is a diode representation of NPN and PNP bipolar junction transistors and their conductance polarities.
The other is the resulting circuit I built - which worked. :) Note: I'm treating a collector as an emitter. :P
You may wish to review your first diagram base current directions.
8)
.99
Quote from: poynt99 on November 25, 2009, 10:08:04 PM
You may wish to review your first diagram diode directions.
8)
.99
I realize this is a terrible model description. ::) In fact, there should a different symbol set altogether.
In any event, feel free to post any transistor hacks, it's always interesting to see good info.
I've reposted the picture. Here are the official models, I do think it easier to simplify the iconography a bit though.
Not sure if this would be considered a hack, but it is different or unconventional being that it is reversed-biased. I don't take credit for this btw.
QuoteREVERSE BIAS OSCILLATOR
There are a number of npn transistors that will oscillate in the audio range when reverse biased.
Minimum supply voltage is 7V for low power transistors such as BC109, BC238 and 2N2222A
(about 10V for the latter), it becomes 12V for medium power transistors such as BD139 and is
16V for power transistors as BUX22 and 2N6543. Current drain is 4mA at 9V and frequency of
oscillation is 550Hz. The base is normally left open.
.99
PS. Check your NPN vs. PNP in your
transistor_hacking.png diagram.
the JFET does a great job ... as i understand ...
;)
the jfet is left open as well and is a floating gate .. triggered from the coil ... it is used to keep it in tune so as to avoid drift..
one could say a self tuneing trick ..
bill beaty static dector .... or something been for ever ..
ist!
Hi jadaro2600,
ask member PESE in this forum. He has discovered this negistor-effect way back in the 70es I guess.
He can explain it in detail
http://www.keelynet.com/zpe/negistor.htm (http://www.keelynet.com/zpe/negistor.htm)
Regards
Kator01
Thankyou all,
Your diagram in your first post is now correct (the one above is not), but the NPN and PNP symbols to the right need to be swapped vertically, so that the NPN is beside the NPN model, and the PNP is beside the PNP model.
Here is the NPN.
.99
Quote from: poynt99 on November 26, 2009, 08:29:39 PM
Your diagram in your first post is now correct (the one above is not), but the NPN and PNP symbols to the right need to be swapped vertically, so that the NPN is beside the NPN model, and the PNP is beside the PNP model.
Here is the NPN.
.99
Let's just use your model!~
Considering the nature of the conductance, it may be inappropriate to even use the diode symbol in my drawings, after all, only the B-E or B-C is the diode.. pleh.
But if anyone wishes to edit this, here is the Gnome DIA file for it.