I just thought of a couple of precision voltage switches. 100 should be easy.
100circuits.com ?Old school two transistor interface (with a 555!)
Teletype Current Loop
New(er) school two transistor interface:
Transistor Based Level Shifter
Thank you,
Fake! More than two transistors.
If that's the way you feel just drop the 555 and spin it into a current loop supply. ;0)
Thank you,
don't forget to register 101 ;)
NT
I just remembered the circuit of the original DTMF phones that had 1 transistor forming two oscillators. It doesn't fit you're criteria, but it was so unique and ingenious it begs the question of whether there are many more possibilities with 2 transistors.
but
So hang a follower on it. ;)
Cheers
Phil Hobbs
Did we do avalanche pulse generator?
Too many parts.
The trick is the varistors across each resonant tank. Each tank becomes an amplitude self-limiter. The tanks are in series with the negative resistance of the transistor. In those days, transistors were expensive but transformers and varistors were relatively cheap.
And Western Electric had no competition.
Yeah. Two resistors and one transistor should do it.
I prefer 100twotransistorcircuits.com, longer but very descriptive.
Mikek
If that's how you guys feel just spin it into a two way shifter. ;0)
BTW, a superior schematic exists somewhere out there in cyberspace but it's beyond my google-fu to find it a second time. This thread just motivated me to now print and paste bookmarks into my "dead tree" lab book for posterity.
Thank you,
If you can fit in a second transistor, we should add it. A follower on the trigger, maybe.
Cheers
Phil Hobbs
Does the two opto-coupler flip-flop count as unique?
Steve
Sure: (diode strapped BJT) + (B-E resistor biased BJT). Triggered avalanche switch. :)
(Which is also an application that needs the diode-strapped BJT, and not just a diode.)
Tim
*Registering 100transistorlabs.com as we speak* :^)
Tim
Well, we could argue about it. My take is that a diode counts as a transistor for this purpose.
Cheers
Phil Hobbs
If you're going to pwn the concept like that, you have to do all the work.
Cheers
Phil Hobbs
The analysis is beyond me. Would it be possible to do this with RC tanks or do you need transformers for isolation?
I'd like to see an RC circuit for 2 oscillators with one transistor so I could try it. Varistors are available aren't they?
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