How many transistors in a ...

Started by Tim Wescott in sci.electronics.design5 years ago 60 replies

So, I kinda hit a threshold in a recent YouTube video when the announcer just casually threw out "the transistor acts like a switch..." I'm...

So, I kinda hit a threshold in a recent YouTube video when the announcer just casually threw out "the transistor acts like a switch..." I'm kind of curious about the world proportion of transistors that operate in linear mode as opposed to being entirely off or entirely on. So a typical computer would have millions of transistors in the processor and memory and GPU and whatnot that are...


hot schmitt trigger action

Started by bitrex in sci.electronics.design5 years ago 3 replies

It takes a -300mV P2P sine wave with a 2V supply and turns it into a squared-up pulse train. The quiescent voltage at the base of switching...

It takes a -300mV P2P sine wave with a 2V supply and turns it into a squared-up pulse train. The quiescent voltage at the base of switching transistor Q2 seems to be pretty stable with temperature variation, only a couple of mV change over 0-70 degrees C. Also seems to work out to a couple MHz, so there's that. Unfortunately, it does use five transistors other than the switch. :-( Bu...


Amplifier transistor substitution.

Started by Sylvia Else in sci.electronics.design5 years ago 20 replies

The smoke escaped from my old oscilloscope today. I've determined that it came out of R740, to the bottom right of the circuit...

The smoke escaped from my old oscilloscope today. I've determined that it came out of R740, to the bottom right of the circuit diagram. https://www.dropbox.com/s/9053dnyr0izv88r/XAMP.PDF?dl=0 This is because T711 has shorted out. Not very surprisingly I cannot source a replacement BF472, so I need to find a substitute. This is the final X-axis amplifier, so we're not talking high ...


Nice Small HV-ish Diode

Started by Tim Williams in sci.electronics.design4 years ago 17 replies

https://industrial.panasonic.com/content/data/SC/ds/ds4/DA2JF8100L_E.pdf 800V, 200mA, 0.6pF @ 0V, 10ns, SOD-323F Tim -- Seven Transistor...

https://industrial.panasonic.com/content/data/SC/ds/ds4/DA2JF8100L_E.pdf 800V, 200mA, 0.6pF @ 0V, 10ns, SOD-323F Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: https://www.seventransistorlabs.com/


measuring uV

Started by Colin Butterfield in sci.electronics.design8 years ago 21 replies

Hi there,I'm new to the group and need to match transistors for a synth pro= ject.I have diagrams for a transistor matching cct but need to...

Hi there,I'm new to the group and need to match transistors for a synth pro= ject.I have diagrams for a transistor matching cct but need to measure diff= erences in the region of 50uV.My digital meters lowest DC scale is 200mV.I = know you can get more sensitive DVM's but these seem to be quite costly and= would defeat the object of matching your own transistors.Is there a way of= increasin...


LTSpice Sim of Strange Old Transistor Circuit

Started by Robert Miller in sci.electronics.design4 years ago 6 replies

I decided to delve deeper into the mystery. Here is an .asc file of the strange circuit previously under...

I decided to delve deeper into the mystery. Here is an .asc file of the strange circuit previously under discussion. https://app.box.com/s/cwlnjt5zh14ubdaul4odvhcehw2tnapa Unless I have made an error, it appears to be non-functional. I am now preparing a bonfire for my collection of such old documents. Robert Miller


sag wires

Started by John Larkin in sci.electronics.design3 years ago 20 replies

It's too long a story to tell here, but there's a party that builds a gadget that we designed, under license from us. They use...

It's too long a story to tell here, but there's a party that builds a gadget that we designed, under license from us. They use contract manufacturers who make near-zero profit. Two years ago, an NPN RF transistor went EOL, and they knew it but did nothing. No CM is going to buy and stock a couple reels of EOL parts. So now they can't build the gadget or ship their product. So, after ov...


Dual FET mixer.

Started by Jamie in sci.electronics.design9 years ago 8 replies

Does any one have a part # and source to get a modern dual gate RF mixer FET transistor? This would have to be a through hole or an SOT or...

Does any one have a part # and source to get a modern dual gate RF mixer FET transistor? This would have to be a through hole or an SOT or something close to that I could fit in. wouldn't mind one that can operate up in the high end like 1 Ghz or better. This is just a curiosity question because I may have a need for one as a replacement and also a few for a project idea. I d...


What semiconductor hides behind code H72P?

Started by petrus bitbyter in sci.electronics.design7 years ago 5 replies

So I have an SMD semiconductor - most likely a transistor - in a SOT-223 package marked H72P. Found several lists of SMD semicondector codes on...

So I have an SMD semiconductor - most likely a transistor - in a SOT-223 package marked H72P. Found several lists of SMD semicondector codes on the net but no H72P. Anyone knows what kind of beast I'm dealing with? petrsu bitbyter


Small voltage detector

Started by Piotr Wyderski in sci.electronics.design6 years ago 26 replies

Hello, I know that there are hordes of nice comparators in SOT-23, but just out of curiosity: is it possible to build a small voltage...

Hello, I know that there are hordes of nice comparators in SOT-23, but just out of curiosity: is it possible to build a small voltage (relatively to GND) detector using just one transistor and no negative power supplies? If the voltage is > = VBE, i.e. 0.7V, then the task is a no-brainer, but how about half of that, say, 0.3V? Best reagrds, Piotr


Tranistor or FET recommendation

Started by mj in sci.electronics.design9 years ago 3 replies

I have a movement detector producing 0V at idle and up to 0.4V-0.5V when th= ere is a movement. This output goes to another device whose logic...

I have a movement detector producing 0V at idle and up to 0.4V-0.5V when th= ere is a movement. This output goes to another device whose logic level Hig= h Vih is > 1.3V and Low is


Superhet & SuperSpice & Nostalgia

Started by Kevin Aylward in sci.electronics.design2 years ago 1 reply

All.... A reminder that SS was freebeed a while ago...just download the current install. For those real analog enthusiasts that remember...

All.... A reminder that SS was freebeed a while ago...just download the current install. For those real analog enthusiasts that remember the 6 transistor Superhet AM radio..... There is a fully working front end simulation schematic in the examples. It has all the key features such as the self oscillating mixer and 3 stage IF filters and detector Just load in: SuperHetRa...


Transistor Phase Inverter Values

Started by Anonymous in sci.electronics.design8 years ago 87 replies

I have a complex low frequency signal from which I need to produce two outputs of equal amplitude but inverted in phase. I would prefer not to...

I have a complex low frequency signal from which I need to produce two outputs of equal amplitude but inverted in phase. I would prefer not to use a transformer due to size. Here is the circuit I am considering. http://www.4shared.com/photo/CDpvTMJW/43_1_Large_Signal_Amplifiers.html This is low current, so I would just use a BC547 or the like. Can anyone please tell me how to prope...


Recommend a CAD program please.

Started by Geoffrey S. Mendelson in sci.electronics.design6 years ago 30 replies

I need to draw some simple schematics. 5 to 10 components. Long ago I did them with MacDraw. 30 years later I am looking for something as...

I need to draw some simple schematics. 5 to 10 components. Long ago I did them with MacDraw. 30 years later I am looking for something as simple, runs under windows and has a library of common components (resitor, capacitor, transistor, diode, fuse). In short something with not much of learning curve that will do the job. Does not need to do PCB layout, circuit analysis, etc. It does ...


ADI Survey

Started by Tim Williams in sci.electronics.design5 years ago

This is interesting, "As ADI's globally authorized distributor, Mouser would like to inform you that Analog Devices (ADI) would like to pay...

This is interesting, "As ADI's globally authorized distributor, Mouser would like to inform you that Analog Devices (ADI) would like to pay you $150 and it will only require 45 minutes of your time." I haven't bought much from ADI in the last years, so Idunno their motivation ... unless that's the point? :^) Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation...


OPA860 ("perfect" transistor)

Started by George Herold in sci.electronics.design7 years ago 9 replies

Well I'm a little slower than piglet, and I'm only up to section 2.3.6 in AoE3. (or is it AoE III?) There H&H mention the opa860, which I...

Well I'm a little slower than piglet, and I'm only up to section 2.3.6 in AoE3. (or is it AoE III?) There H&H mention the opa860, which I would have skipped, except I'd just been looking at that "OTA" thanks to Phil H's mention of it in some thread that slid into multipliers. Anyway I spent some of last night reading the spec sheet. http://www.ti.com/lit/ds/symlink/opa860.pdf Which...


Another goofy MOS symbol...

Started by Tim Williams in sci.electronics.design4 years ago 15 replies

...This time, spotted in a TI switchmode controller (LM25119)...

...This time, spotted in a TI switchmode controller (LM25119) worksheet: https://www.seventransistorlabs.com/Images/GoofyMOSSymbol.png Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: https://www.seventransistorlabs.com/


Does a wide bandgap JFET glow under forward bias?

Started by Tim Williams in sci.electronics.design1 year ago 23 replies

Yes. https://www.eevblog.com/forum/projects/transistors-die-pictures/msg3234138/#msg3234138 Tim -- Seven Transistor Labs, LLC Electrical...

Yes. https://www.eevblog.com/forum/projects/transistors-die-pictures/msg3234138/#msg3234138 Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/


Interesting thermal test condition

Started by Tim Williams in sci.electronics.design8 years ago 2 replies

Fig 8 http://www.comchiptech.com/cms/UserFiles/GBPC15005W-G%20Thru381547.%20GBPC5010W-G%20Series%20Rev B.pdf For a moment, I was wondering if...

Fig 8 http://www.comchiptech.com/cms/UserFiles/GBPC15005W-G%20Thru381547.%20GBPC5010W-G%20Series%20Rev B.pdf For a moment, I was wondering if they were doing some sort of dielectric heating test. Tim -- Seven Transistor Labs Electrical Engineering Consultation Website: http://seventransistorlabs.com


new 3D XPoint memory

Started by Jamie M in sci.electronics.design6 years ago

Hi, This new transistor-less memory seems like it might have more applications than just memory, ie maybe the memory cells can be used in an...

Hi, This new transistor-less memory seems like it might have more applications than just memory, ie maybe the memory cells can be used in an analog way too, or some non-digital addressing of the rows/columns/3d layers. http://arstechnica.com/gadgets/2015/07/intel-and-micron-unveil-3d-xpoint-a-brand-new-memory-tech nology/ Any ideas what the memory could be used for besides memory, ie a