Transistor Hacks

[jadaro2600]

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.

[poynt99]

You may wish to review your first diagram base current directions.


.99

[jadaro2600]

You may wish to review your first diagram diode directions.


.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.

[poynt99]

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.

REVERSE 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.

[innovation_station]

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!