I don't have a model of the antique obsolete Oriental S8050 transistor for my simulation program.
Modern transistors with simulation models are not available in his ...-world country.
obsolete? S8050 is still producing in china and most of those chinese analog devices still use this transistor, s8050 can handle 1.5A current,100mhz and has 1W power, unlike those 200ma junk 2n3904 and bc547etc.
I have NEVER bought a cheap Chinese transistor. The datasheets for the S8050 say it is NPN or PNP (they don't know what it is). I think Wing-Shing has it wrong.
A 2N4401 has the same or better spec's and is made by many American semiconductor manufacturers so I use them instead.
ppl,
i need a 3V to 9v converter circuit for my new project, so i want know and learn about them, can anyone post a schematic that is easy to build? I got a 3.7V battery with 750mA current and want 9v or 12V out of it
No it is not. That circuit does not work. Z!dd!k said he modified it: "i changed the 2nd transistor with s8050 and removed the final amp transistor, and replaced the v.cap with a fixed "15pf" cap, finally the emitter resistor of 2nd transistor replaced with 100ohm, that is all i modified".
I posted a simulation that might be his modified circuit except I used an American transistor instead of a cheap Chinese one and I added 5pf of stray capacitance to the 15pF fixed capacitor.
The oscillator does not oscillate when a 75 ohm 1/4 wave whip antenna is connected to the collector of the oscillator. Maybe he connected the antenna to the emitter.
Here is what I think is the circuuit Z!dd!k used:
Here is a circuit for a 100 ma discrete boost converter. It's not the best, and I have not built it but it looks okay. There are lots of single chip solutions out there but if you can't get them maybe this will work.
You know, when I wrote the data sheet for the LM2731 (and built up all the circuits) I was hoping people would actually read it..... I posted the link to it in the second post in this whole thread. It's the best part for this type of app.
BTW: it has guaranteed performance specs with VIN as low as 2.7V.