I have a switching application where a single bipolar transistor might be used. The AC input is about 300mV and the transistor needs about 700...

I have a switching application where a single bipolar transistor might be used. The AC input is about 300mV and the transistor needs about 700 mV to switch on. My idea is to construct a voltage divider using a diode which will produce about a 600mV drop across the diode and a voltage divider of 2 equal resistors to set the transistor base voltage at about 300 mV so the transistor will sw...

I find myself in a situation where I am repairing some high end audio amps and cassette decks that have house numbered semiconductors, mainly...

I find myself in a situation where I am repairing some high end audio amps and cassette decks that have house numbered semiconductors, mainly transistors as well as JDEC p/n that are NLA. I have found a few transistors that are dead and need to be replaced. Fortunately, they are in parts of the amp where the other channel has an identical transistor. Having one transistor as a bas

I found old mosfet transistor IRF843, using 20k and 70k resistor, i manage to set the voltage at transistor gate to 3.9 volt and using 1uF to...

I found old mosfet transistor IRF843, using 20k and 70k resistor, i manage to set the voltage at transistor gate to 3.9 volt and using 1uF to channel the 27mhz rf signal to the transistor gate, i manage to get an audio from 8ohm speaker connected to the transistor drain. I'm using about 5.3 volt power supply from transformer. The audio is loud and clear. The mosfet gate can received

Transistor as heater/ temp sensor. So in looking for a small heater one idea is to use a transistor as heater. And to take the idea one step...

Transistor as heater/ temp sensor. So in looking for a small heater one idea is to use a transistor as heater. And to take the idea one step further to use the same transistor (sequentially) As first a heater then a temp sensor. So the first question is then how to use it as a heater. I was thinking of controlling the current At some fixed voltage.. something like this, https://www...

Well not a exactly a vacuum, they fill it with helium. "...NASA?s Ames Research Center is going back to the future with its new vacuum...

Well not a exactly a vacuum, they fill it with helium. "...NASA?s Ames Research Center is going back to the future with its new vacuum transistor ? a nanometer-scale vacuum tube that, in early testing, has reached speeds of up to 460GHz." > https://www.extremetech.com/extreme/185027-the-vacuum-tube-strikes-back-nasas-tiny-460ghz-vacuum -transistor-that-could-one-day-replace-silicon-fets

Could some RGF/microwave guru on this newsgroup please help ? I am looking at the datasheet for a ONSemi RF transistor, with the S parameters...

Could some RGF/microwave guru on this newsgroup please help ? I am looking at the datasheet for a ONSemi RF transistor, with the S parameters listed for various frequencies. What would be a quick and easy(that I can code as a simple C program) way to convert these to the corresponding Zin and Yout. Thanks in advance for your hints/suggestions.

https://www.farnell.com/datasheets/2353855.pdf I bought a few of these. I don't know what is intended by "digital transistor" since the...

https://www.farnell.com/datasheets/2353855.pdf I bought a few of these. I don't know what is intended by "digital transistor" since the charge storage time defeats any attempt to use them at a high frequency, and there's no way to add a Schottky diode to prevent saturation, or a speed-up capacitor across the base resistor. I'm using this and the corresponding PNP type to do level shift...

Where can one get them, and is there a wide range of transistor type represented? How good are they, eg: E-B breakdown correct, beta at...

Where can one get them, and is there a wide range of transistor type represented? How good are they, eg: E-B breakdown correct, beta at given sets of Ic VS temp correct?, Vbe VS temp and VS Ic correct? Are there models for each manufacturer?

I tried building a single transistor LED flasher like this...

I tried building a single transistor LED flasher like this : http://cappels.org/dproj/simplest_LED_flasher/Simplest_LED_Flasher_Circuit.html I didn't have the recommended 2n2222 - I tried with a BC548, 2n2369 and 2n3055 - None of them work. I'm using a trimpot set to 2 kiloohms and a 470 microfarad capacitor. Instead of a 100 ohm resistor I put 3 superbright LEDs in series. I get 1.2 v...

OK, I need to charge a capacitor with a stable constant current. The desired slope is about a volt per nanosecond. So I did...

OK, I need to charge a capacitor with a stable constant current. The desired slope is about a volt per nanosecond. So I did this: https://dl.dropbox.com/u/53724080/Circuits/Fast_Ramp.JPG Things like this tend to oscillate, so I used a fairly slow, high-beta transistor, BCX71K. The ferrite in the collector is supposed to isolate the ramp cap from the transistor capacitance and make ...

I am new to Spice as well as LT Spice. I have input most of my circuit after spending much time looking for components. I have not run the...

I am new to Spice as well as LT Spice. I have input most of my circuit after spending much time looking for components. I have not run the circuit yet since I have a hole where a unijunction goes. The circuit additionally uses a triac, scr and transistor. I found the *Programable Unijunction Transistor pkg: TO-226AA .SUBCKT X2N6027 1 2 3 for a "generic" (to me) unijunction. B...

Does anybody know of any germanium transistor for audio use that are in current production? Also are the NTE102 and NTE103 or any other NTE...

Does anybody know of any germanium transistor for audio use that are in current production? Also are the NTE102 and NTE103 or any other NTE offerings any good for audio, fuzz boxes etc?

Could some electronics guru here please help ? What is the best way to select a transistor for an oscillator ? Consider a Colpitts oscillator...

Could some electronics guru here please help ? What is the best way to select a transistor for an oscillator ? Consider a Colpitts oscillator running at 5 MHz. The following are the analysis steps. 1. Select a value for the LC tank capacitor C1 = C2 = C 2. Select a load e.g., R=50 Ohm 3. To start oscillations, gmR > C2/C1. In this case gmR > 1 4. Using the oscillation frequency and

These are fun! https://www.seventransistorlabs.com/Images/FlashlightTrio.jpg Triple 'LVC buffer drives the power transistor at 5 or 6...

These are fun! https://www.seventransistorlabs.com/Images/FlashlightTrio.jpg Triple 'LVC buffer drives the power transistor at 5 or 6 nanoseconds risetime, not bad at all. Design is very hackable; by changing around a couple of resistors, it makes a portable bench supply! Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: https:/...

Hi all,   I'm following a group discussing building a Q meter. HP has a two transistor Impedance Converter Ass'y. >...

Hi all,   I'm following a group discussing building a Q meter. HP has a two transistor Impedance Converter Ass'y. > https://www.dropbox.com/s/n5gj8powzph6611/HP4342A%20impedance%20converter%20and%20injection%20tr ansformer..jpg?dl=0 One builder got down to 0.86? output impedance at 50kHz, 1.05? at 1MHz, on up to 7.70? at 30MHz after trying several common transistors for the first trans

The circuit linked below appears to be a conversion of a three stage inverting tube amp tube to a transistor circuit, powered by...

The circuit linked below appears to be a conversion of a three stage inverting tube amp tube to a transistor circuit, powered by 3VDC. https://app.box.com/s/dwflbolnqe58ra9c1kssqjuq14dulxo0 It appears to be intended to capture high frequency ambient signals and re-broadcast them. It may also be designed to self-oscillate to add a carrier wave. In any case, I would like to build it o...

Hi, My Peugeot 406 heater blower control module ceased to work the other day, and its power transistor is open. Must be an NPN since it is...

Hi, My Peugeot 406 heater blower control module ceased to work the other day, and its power transistor is open. Must be an NPN since it is supposed to PWM the blower motor to earth (-12V). When searching N344* I find a lot of references to 2N344n.. (2N3440, 2N3442... etc) but not this the exact version. I've uploaded an image of the 'fat' case here: http://kuntigi.net/download/N34...

A question for the electronics gurus here. Recently I have done continous and pulsed DC sweep to examine the Ice - Vbe @ continuous and pulsed DC...

A question for the electronics gurus here. Recently I have done continous and pulsed DC sweep to examine the Ice - Vbe @ continuous and pulsed DC Vce for the SiGe BFQ790 transistor. In continous DC mode, the Vce is set at some allowed value(less than Vce max.) is swept over a lower - upper limit range, and Ice is measured. The the results are the familiar family of curves one finds

I'm working on a small circuit that will be powered by a 9V battery. I would like to combine the functions of a soft power switch and reverse...

I'm working on a small circuit that will be powered by a 9V battery. I would like to combine the functions of a soft power switch and reverse battery protection in a single device. I think the answer may be to use a PNP transistor on the high side, with a base resistor to ground - actually to ground through a physical momentary switch, or indirectly to ground via an NPN transistor cont...

or equivalent. I only need one but would like to have some spares. I have looked all over. I would even take a datasheet. Oh, please email...

or equivalent. I only need one but would like to have some spares. I have looked all over. I would even take a datasheet. Oh, please email if you have one/any as I don't check here often. Thanks for any help. j/b