This is a Germanium transistor... -----Original Message----- From: Maris To: PICLIST@MITVMA.MIT.EDU Date: Wednesday, September 01, 1999 3:02 PM Subject: Re: Pseudo-random number generation. >For most transistors it takes around 7 volts to break down the reverse >emitter/base junction so this circuit may not work at 5 volts. Maybe you >can substitute a low voltage zener for the transistor. >Maris > > >At 09:13 AM 9/1/99 +0200, you wrote: >>Hi, >>as more people wished, here is the true h/w random number generator: >> >> White noise generator, design by dr. Imre Bartfai, 8/30/1999 >> >> +--------------------------------------------------------------------- Vdd >> | 220k 220k 5V >> | +---\/\/\---+ +---\/\/\---+------+ >> | | | | | | >> | Ge | |\ | | +------+ \ >> | EFT317 PNP +-----+----|- \ | | | / 220k >> | C | | | >-+----| |----+ | |\ \ >> | |/ \ +-------|+ / 47n | +-----|- \ | >> +--B| 220k / | | |/ | | | >--+ >> |\ \ | | 1/2 LM358 +----------|+ / | >> |E | | | | | |/ \ >> +----| |----+--+ + + + / 47k >> | 47n | | | | 1/2 LM358 \ >> \ \ \ \ \ | >> 4k7 / 1M / / 2k2 1M / / 2k2 + out >> \ \ \ \ \ >> | | | | | >> +-----------+-----+-----------------------+----+---------------- Vss >> >> Standard TTL can not be driven, but CMOS (and maybe LS) are o.k. >> The power supply must be filtered thoroughly due to the high gain! >> >>Regards, >>Imre >> >>