Hi So I wanted to check the VCE of a transistor in a small converter running at 100kHz, expected to see about 100mV above ground as...

Hi So I wanted to check the VCE of a transistor in a small converter running at 100kHz, expected to see about 100mV above ground as the saturation voltage of the NPN, increasing linearely since magnetising current increasing. I saw nothing like that, debugging and found the scope (Tek DPO5000) somehow saturates with high voltage inputs. The signal is a square wave of 100kHz, 25V peak to...

I'm designing a small simple circuit in which a MOSFET drives a low-power load. The very low frequency gate drive may, on rare occasions,...

I'm designing a small simple circuit in which a MOSFET drives a low-power load. The very low frequency gate drive may, on rare occasions, exceed the max Vgs rating of 12V by about 1V, possibly 2V. There are a number of ways to limit the gate voltage but I want to avoid them and keep the circuit as simple as possible, and it won't cause a disaster if the transistor fails. What do you thi...

The only problem that I may have created is the transistor, I used BC547B with HFE of 200 to 450 vs BC549C with HFE of 420 to 800. All I had...

The only problem that I may have created is the transistor, I used BC547B with HFE of 200 to 450 vs BC549C with HFE of 420 to 800. All I had in my junk box. I built a low noise amplifier, original design was for a 30v supply, I chose to correct the values for a 15V supply. Designer does have a 12v version, my values are close.  I did set an emitter resistor to have equal clipping....

Q. Relative power dissipation capability of TO-92 transistor packages (viz, Zetex E-line parts) vs. sot-23 packages. More on this in my...

Q. Relative power dissipation capability of TO-92 transistor packages (viz, Zetex E-line parts) vs. sot-23 packages. More on this in my next post, first some background. One of my design interests is high-frequency, high-voltage power amplifiers. For example, I'm doing a 45V, 5A peak, DC-10MHz amplifier. My design uses 20 TO-220F power transistors, mounted on a 200W fan-cool...

This is an about -30 dBu sine wave being amplified to about 0dBu by the triode section of a Sylvania 12EC8 triode/pentode "space charge" tube....

This is an about -30 dBu sine wave being amplified to about 0dBu by the triode section of a Sylvania 12EC8 triode/pentode "space charge" tube. The plate load is a single transistor gyrator/constant current source. Plate and heater currents are being supplied by a "China Special" boost converter module that's stepping up a 4 "C" cell battery pack. http://tinyurl.com/zeegduc Yick. Lots...

I'm making some replacement boards for a system I designed a while ago. 1980, actually. The power regulator board used a couple of LM376's,...

I'm making some replacement boards for a system I designed a while ago. 1980, actually. The power regulator board used a couple of LM376's, a nice little DIP8 voltage regulator that drives an off-board heatsunk PNP pass transistor. LM376 seems to be unavailable. But I can't find a substitute, namely a linear voltage regulator controller with foldback capability and external PNP pass tr...

Have a circuit that needs repair. Uses a TIP125 (NPN, Darlington) emitter tied to Vbb (~20VDC). Collector to load, then to ground. 1K resistor...

Have a circuit that needs repair. Uses a TIP125 (NPN, Darlington) emitter tied to Vbb (~20VDC). Collector to load, then to ground. 1K resistor (R1) pullup on Base to Vbb, and a second 1KR (R2) to the TTL controller. Problem is of course, that R2 puts the ~20VDC to the TTL output gate on a 74LS138. Trying to solve this without a driver transistor. The circuit is for a 1ms ~20V strob...

Could some transistor guru here plwase provide some pointers on this ? I am looking for some good books on heterogeneous junction transitors. It...

Could some transistor guru here plwase provide some pointers on this ? I am looking for some good books on heterogeneous junction transitors. It is odd that while heterogeneous transistors are replacing traditional homogeneous junction transistors in RF|microwave and high power switching applications, there is no good reference book on thse devices. All hints|suggestions will be greatly ap...