Transistor part number suffixes--215? 235? Whazzat?

Started by Phil Hobbs in sci.electronics.basics5 years ago 11 replies

So I bought a reel each of BF862-235 and BF862-215. Other parts seem to have the same suffixes, but a quick web search comes up with...

So I bought a reel each of BF862-235 and BF862-215. Other parts seem to have the same suffixes, but a quick web search comes up with nothing useful, and the datasheet links for the two types of parts go straight to the same place. I'd guess this has something to do with ROHS/halogen free/greenie-knotted-knickers-of-the-month, but don't know for sure. Wisdom? Thanks Phil Hobbs ...


Transistor circuits, book, devices, etc

Started by Peter Percival in sci.electronics.basics5 years ago 51 replies

I though I'd like to learn a bit about electronics and to that end I'd like to buy a book of transistor circuits, a breadboard, and various...

I though I'd like to learn a bit about electronics and to that end I'd like to buy a book of transistor circuits, a breadboard, and various components to experiment. Can anyone recommend a book that uses transistors that I can buy in the UK? Also, who is a good supplier of components generally? -- Do, as a concession to my poor wits, Lord Darlington, just explain to me what you reall...


sequential transistor relay

Started by Anonymous in sci.electronics.basics5 years ago 1 reply

Good Day Sir/Ma'am, I'm a technician and I am in need of schematic diagram of a sequential four transistor driven relay which i will needing...

Good Day Sir/Ma'am, I'm a technician and I am in need of schematic diagram of a sequential four transistor driven relay which i will needing for my project as part of my study. I have a single input source driven by LDR, the first relay should be turned on and then off,while the second, third and fourth relay should be remain off, then when the LDR is active the second relay sho


one transistor amplifier help

Started by amdx in sci.electronics.basics5 years ago 32 replies

I have the following amp. It originally had a 12V supply voltage, In an effort to get a larger swing on the output, I raised that to 24V. ...

I have the following amp. It originally had a 12V supply voltage, In an effort to get a larger swing on the output, I raised that to 24V. I now get 12.5Vpp on the output, I want to maximize the output signal. A gain of 3 will work for my circuit. What changes can I make to maximize the output swing. The input is at maximum before distortion is seen. > https://www.dropbox.com/s/07j


Transistor Hard Saturation - pg224 - Malvino

Started by veek in sci.electronics.basics5 years ago 2 replies

'A designer who wants a transistor to operate in the saturation region under all conditions often selects a base resistance that produces a...

'A designer who wants a transistor to operate in the saturation region under all conditions often selects a base resistance that produces a current gain of 10. ' http://pix.toile-libre.org/?img=1493526531.png http://pix.toile-libre.org/upload/original/1493526562.png I don't understand what he's doing with the math (it's not complicated math but he's trying to illustrate an idea that I...


What is a load line - intuitively

Started by veek in sci.electronics.basics5 years ago 10 replies

http://pix.toile-libre.org/?img=1493527288.png That's a typical graph of Vce vs Ic for a bunch of Ib as provided by the manufacturer. Is my...

http://pix.toile-libre.org/?img=1493527288.png That's a typical graph of Vce vs Ic for a bunch of Ib as provided by the manufacturer. Is my understanding correct: We create a loadline so that we can operate the transistor's collector ckt in a linear fashion for a varying base input. Basically there are an infinite set of Vce vs Ic curves for each and every base current value possib...


Removing battery corrosion

Started by Anonymous in sci.electronics.basics4 years ago 19 replies

I got an old AM-FM pocket transistor radio which looked good and clean till I opened the battery compartment. Very corroded carbon...

I got an old AM-FM pocket transistor radio which looked good and clean till I opened the battery compartment. Very corroded carbon zinc batteries were in it. After removing them, I cleaned off as much of the corrosion as possible by scraping with a plastic stick, and scrubbing with q-tips and rubbing alcohol. That got rid of most of it, and I was surprised to find the battery clips are not ba...


Old Uneducated Me Again, Transistor Circuit

Started by Anonymous in sci.electronics.basics4 years ago 7 replies

I have designed and built a few things that worked. But I always used the sledge hammer approach when it comes to impedance. I made the output...

I have designed and built a few things that worked. But I always used the sledge hammer approach when it comes to impedance. I made the output impedance of the stage much lower than the input impedance of the next. Upon further reflection, I think that sometime this is a waste and actually may be not all that effective. These are the the throes of an almost old Man so don't tear


Really basic transistor question

Started by Bob Engelhardt in sci.electronics.basics3 years ago 3 replies

I want to build a device that will take my phones off line. The phones are connected to a Vonage modem that (I'm sure) uses the POTS standard....

I want to build a device that will take my phones off line. The phones are connected to a Vonage modem that (I'm sure) uses the POTS standard. Which is 50v DC at "idle"/on-hook and 90v (RMS) 20 Hz superimposed on that for ringing. 90v RMS is 250v p-p offset by 50v is -75 to 175 p-p. Off-hook is 10v DC with low voltage audio superimposed on that. The phones on the line are all electron...


Generating this negative pulse?

Started by Terry Pinnell in sci.electronics.basics3 years ago 15 replies

I have a couple of simple 555 monostables, the first to delay the triggering of the...

I have a couple of simple 555 monostables, the first to delay the triggering of the second. https://www.dropbox.com/s/6uboy3fgd0ixhxa/GenerateNegPulse-1.jpg?raw=1 But I'm struggling to extract the brief -ve pulse required for the Main mono. I thought it would prove simple. But bread-boarding various combinations of R, C, diode and NPN or PNP transistor has so far not yielded a winning comb...


Teaching Transistor Theory

Started by Cursitor Doom in sci.electronics.basics2 years ago 19 replies

I've just had a pedagogic revelation! Here it is: Transistor theory is much more effectively taught if explained as a *discovery* (which it...

I've just had a pedagogic revelation! Here it is: Transistor theory is much more effectively taught if explained as a *discovery* (which it was) than as an invention (which it never was). All these decades I've been wrestling with this conundrum and all it took to clear things up was a handful of these amazing mushrooms. Yay! :-D Okay, I was joking. But seriously, think about it. The co...


Semiconductor manufacturing locations

Started by Michael Darrett in sci.electronics.basics3 months ago 4 replies

Hello, In light of the cargo ship debacle in the Pacific, I am trying to determine which companies still manufacture semiconductors in the US...

Hello, In light of the cargo ship debacle in the Pacific, I am trying to determine which companies still manufacture semiconductors in the US and Europe. I found these: https://www.thomasnet.com/articles/top-suppliers/semiconductor-suppliers-manufacturers/ https://www.bisinfotech.com/top-ten-transistor-manufacturers/ Apparently Analog Devices is headquartered in the US but it's unclea...


Why is Vbc = Vbe - Vce ?

Started by jalb...@bsu.edu in sci.electronics.basics13 years ago 8 replies

I have seen in various places the equation Vbc = Vbe - Vce for NPN and PNP transistors. It may seem obvious to others but I just don't see how...

I have seen in various places the equation Vbc = Vbe - Vce for NPN and PNP transistors. It may seem obvious to others but I just don't see how this is true. Could someone please throw me a bone? Thanks


audio amplifier output transistors

Started by Anonymous in sci.electronics.basics13 years ago 8 replies

I noticed that TR7 is PNP and TR9 is NPN here: http://www.dself.dsl.pipex.com/ampins/dipa/dpafig1.gif Then over here, TR7 is NPN and TR9 is...

I noticed that TR7 is PNP and TR9 is NPN here: http://www.dself.dsl.pipex.com/ampins/dipa/dpafig1.gif Then over here, TR7 is NPN and TR9 is PNP: http://www.dself.dsl.pipex.com/ampins/dipa/dpafig33.gif Are these correct, or in error? Also - for building audio amps "on the cheap", would TIP41C/TIP42C do for output transistors in these schematics? Thanks, Michael


Joule Thief - still not working....

Started by fungus in sci.electronics.basics12 years ago 161 replies

I just got some proper parts to start making joule thieves but I'm still having problems. The circuit is this:...

I just got some proper parts to start making joule thieves but I'm still having problems. The circuit is this: http://www.artlum.com/jt/joulethief.gif Except I have R1 and L1 one the other way around (as in the original web page at http://www.emanator.demon.co.uk/bigclive/joule.htm ) The problem is that my transistors keep on overheating and dying. Why should this be? I'm using a 2N22...


White Noise Source

Started by Chiron in sci.electronics.basics10 years ago 72 replies

I need a source of white noise (audio). It doesn't have to be perfect. I seem to recall that you could use a zener diode as a white noise...

I need a source of white noise (audio). It doesn't have to be perfect. I seem to recall that you could use a zener diode as a white noise source. Is this true? Are there any other possibilities? I anticipate using a 9-V battery for my power, and a few transistors to amplify the signal to drive earphones. You may ask, "why the heck would he want to do that?" Good question: http:...


pmos switch question

Started by panfilero in sci.electronics.basics10 years ago 2 replies

I'd like to control a switch using a microcontroller, I was thinking I'd feed the output of the microcontroller into an npn that would pull a...

I'd like to control a switch using a microcontroller, I was thinking I'd feed the output of the microcontroller into an npn that would pull a pmos gate low and let current flow, it seems to be working ok in LTSpice except I have a negative spike, when I switch. Is this an ok way to accomplish my goal, and does anybody know what that negative spike is about? I'm using 2 pmos transistors so ...


simple one-shot pulse detector circuit needed

Started by Anonymous in sci.electronics.basics9 years ago 42 replies

Hi all, I seem to recall from distant memory that it's possible to make a pulse det= ector out of two of transistors and a few resistors, but...

Hi all, I seem to recall from distant memory that it's possible to make a pulse det= ector out of two of transistors and a few resistors, but I can't find the c= ircuit anywhere. Searches keep throwing up stuff about astable multivibrato= rs and nand gates and that's not what I'm looking for.=20 Just need to be able to detect a 1 second pulse of 5v on an otherwise 0v li= ne. The pulse co...


Transistors

Started by Uncle Steve in sci.electronics.basics9 years ago 60 replies

Ok, this is a question that is not so battery-charger specific, but is obviously related. So here's a circuit fragment: 18V ...

Ok, this is a question that is not so battery-charger specific, but is obviously related. So here's a circuit fragment: 18V +----+--------__^------/\/\/-----------+ | 2n3055| 0R5 | | | 5W / | | \ 5R10W | | / |_______|>


Ping uncle steve

Started by John Fields in sci.electronics.basics9 years ago 8 replies

Hey, I took time out of my life in order to address your concerns, provided a solution for you with respect to the "Transistors" thread, and yet...

Hey, I took time out of my life in order to address your concerns, provided a solution for you with respect to the "Transistors" thread, and yet you seem to be avoiding acknowledgement of my favor. Why is that? -- JF