Hi I am on the lookout for a cheap 1:1 pulse transformer. Will be using it to drive a MOSFET based Solid State Switch. I know Larkin has...

Hi I am on the lookout for a cheap 1:1 pulse transformer. Will be using it to drive a MOSFET based Solid State Switch. I know Larkin has used the DRQ127 https://www.digikey.dk/en/products/detail/eaton-electronics-division/DRQ127-1R5-R/667262 But, I am looking to see if I can find bottom dollar. I probably wont go to LCSC, so would prefer a known brand. Anyone got a recommendation...

I've never used a mfr model that was a subckt before; I've always added the .MODEL to the LTSpice library file, or edited an existing...

I've never used a mfr model that was a subckt before; I've always added the .MODEL to the LTSpice library file, or edited an existing device. This Vishay MOSFET has a more complex model though, and she ain't loadin' Jim. LTSpice says it can't find the model for M1. I even tried putting the definition right in the .asc, still no joy. I followed the LTSpice help info, as best I could. A...

I've created all kinds of HV circuits in the last 5 years,** and each one needs an external HV supply. So I really need some simple...

I've created all kinds of HV circuits in the last 5 years,** and each one needs an external HV supply. So I really need some simple HV-supply circuits to plop onto these PCB's to make them self-sufficient. Today's circuit is a basic flyback, to convert a 12V,1A wallwort source to 500V max, at 5-10W load. I used a UC3843B running at 100kHz driving a MOSFET switching a 47uH indu...

I've been working on a power supply for antique Teletype selector magnets. These need 120VDC 60mA for the first 2ms or so of each bit time,...

I've been working on a power supply for antique Teletype selector magnets. These need 120VDC 60mA for the first 2ms or so of each bit time, but the sustain voltage needed is only 3-4V. So I've built an isolated boost supply and interface board, all powered from a USB port. The whole project is on Github: https://github.com/John-Nagle/ttyloopdriver where there's an explanation of how...

Proof in case: http://www.ecnmag.com/sites/ecnmag.com/files/legacyimages/ECN/Articles/CS-1109-Figure_02.jpg It's bad enough that AoE3...

Proof in case: http://www.ecnmag.com/sites/ecnmag.com/files/legacyimages/ECN/Articles/CS-1109-Figure_02.jpg It's bad enough that AoE3 stooped to using those MOSFET symbols. (The only problem I can find with the tome! Why did it have to be such an important, and deceptive, problem!? Please Win, if you fix this in a reprint, I will send you the finest bottle of liquor I can find.) ...

I need a mosfet gate driver, to drive two n-fets in a half-bridge (totem pole) config, 5 volts nom in, with some sort of bootstrap for the...

I need a mosfet gate driver, to drive two n-fets in a half-bridge (totem pole) config, 5 volts nom in, with some sort of bootstrap for the upper fet gate. Switcher output will be around 2.5 volts at 5 amps, so the gate drives don't have to be monstrous. I've been working with LTC4442 on a breadboard, but it's really erratic. Sometimes it's beautiful, and sometimes the gate drive breaks ...

I'm making another fast pulse generator, shopping FETs, and noticed a few possibly interesting gizmos: RF MOSFETs. They're built for linear...

I'm making another fast pulse generator, shopping FETs, and noticed a few possibly interesting gizmos: RF MOSFETs. They're built for linear operation. At a glance, they seem to have fairly beefy SOA curves. Up to 600V, too. "N-channel enhancement mode linear RF power MOSFET Ideal for class AB and C industrial, scientific, medical, and commercial applications. VDSS = 500 V ID25=

I might use an LED+mosfet type SSR to switch a voltage divider at the input of an isolated ADC. The ON resistance of the switch is an error...

I might use an LED+mosfet type SSR to switch a voltage divider at the input of an isolated ADC. The ON resistance of the switch is an error contributor, and a super-low Ron is expensive. 1 or 2 ohms is affordable. I'm thinking that driving the LED side from the proper Thevenin source might temperature compensate the ON resistance of the mosfets. Or even program the LED supply with a DAC....

BLDC controller: http://173.224.223.62/motor I am thinking about moving the PIC 3 feet away (closer to the control panel= ) from this...

BLDC controller: http://173.224.223.62/motor I am thinking about moving the PIC 3 feet away (closer to the control panel= ) from this board. There are 6 outputs in 6 possible states. Each pair of= MOSFET can be in HI, LO or KILL (both HI and LO) states. I can add an I/O= expander or shift register to minimize the connections, but that increase = the chance of KILL states due to comm...

We have a mosfet closed-loop programmable current sink that works fine most of the time but behaves badly at startup from zero current or...

We have a mosfet closed-loop programmable current sink that works fine most of the time but behaves badly at startup from zero current or at very low currents. The fix is to drool in a bit of keepalive current so that the loop never goes open and rails low. https://www.dropbox.com/scl/fi/3ql0ew6a2elh562wbsx96/Keepalive.jpg?rlkey=fujknponcgtf31mi3rf072x 5e&dl=0 The 400 volt MMBD5004 would b

It is tempting to make a spot welder from the Maxwell ultracapacitors e.g. the 3000F ones rated for 1900 Amps each. There is something nice...

It is tempting to make a spot welder from the Maxwell ultracapacitors e.g. the 3000F ones rated for 1900 Amps each. There is something nice about the idea of a spot welder that does not draw large pulses of current from the mains, and a cordless spot welder would be a novelty. I figure that something in the region of 10kA to 30kA output current would make it useful enough to justify the...

A rudimentary behavioral model of the Vishay VOM1271 PhotoVoltaic MOSFET Driver has been posted... see VOM1271.zip on the Device Models &...

A rudimentary behavioral model of the Vishay VOM1271 PhotoVoltaic MOSFET Driver has been posted... see VOM1271.zip on the Device Models & Subcircuits page of my website. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASI...

Hi: I have been using MOSFET drivers to pulse LEDs at currents of up to 21A (for 100s of ns to several microsecond pulses) and down to about...

Hi: I have been using MOSFET drivers to pulse LEDs at currents of up to 21A (for 100s of ns to several microsecond pulses) and down to about 22ns for 1A pulses into 1mm^2 power LEDs. I can't get any faster with the drivers I've tried than about 20ns for "parity" optical output power with the 1.0A CW max current typical of blue 1mm^2 LEDs. (see note 1 below) I wish to achieve 10-20n...

I'm going use an insane number of 7x20mm SPST relays, so I'm testing relays and drivers. Here's a...

I'm going use an insane number of 7x20mm SPST relays, so I'm testing relays and drivers. Here's a start. https://www.dropbox.com/scl/fo/ns08x686afbayjsw8c2ab/h?rlkey=m9dr3wdnhd3v6ftdhwga65mzb&dl=0 The waveforms are drain voltage and source current. Two surprises: that little 100 volt logic-level mosfet avalanches happily at just over 100 volts. The drain voltage doesn't ring. Th...

Some LT Spice models have invisible internal nodes that are hard ground. So you can't float them off ground. LTC4444 mosfet driver for...

Some LT Spice models have invisible internal nodes that are hard ground. So you can't float them off ground. LTC4444 mosfet driver for example, half-bridge with + and - power rails. Bummer. I'll just fake the gate driver with a couple of BVs. That will run faster anyhow. I guess I could run the 4444 grounded and AC couple into the gates with DC restore. Lotta hassle. -- ...

Power MOSFETs have highly-nonlinear capacitances. For the new super-junction types, voltages 500V to 800V, nonlinearity can be severe, up...

Power MOSFETs have highly-nonlinear capacitances. For the new super-junction types, voltages 500V to 800V, nonlinearity can be severe, up to 100x. A new Coss spec, effective capacitance, comes in time related (tr) and energy related (er) forms, with a stated voltage, usually 80% of breakdown. It's a fixed capacitance that matches the FET's charging time or energy consumption. Old...

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...

An older and poorly-documented plasma screen (LG 42PC3DV) apparently went 'pop' and developed dark screen. It had the usual bad 5V rail caps...

An older and poorly-documented plasma screen (LG 42PC3DV) apparently went 'pop' and developed dark screen. It had the usual bad 5V rail caps (x9) of the era (mfrd 6 months in 2006), and an overloaded -VY rail. I fixed those issues, to discover that Y_SUS waveform had no 'set-down' ramp. The mosfet generating that ramp can and does produce a -ramp, but only at the termination of the p...

A major meltdown last Friday for my 8ns 1kV SiC MOSFET pulser. After set of tests at 400V and 4MHz repetition rate, with everything working...

A major meltdown last Friday for my 8ns 1kV SiC MOSFET pulser. After set of tests at 400V and 4MHz repetition rate, with everything working fine, I had to increase the frequency. A loose hand slip and I was at 10MHz. That's when the smoke appeared. Blew out a 1-ohm gate resistor, both TO-247 MOSFETs, both 24V gate drivers, the flying regulator and the 150Mbps 50kV/us isolator, a...

Hello I design an electronic load, using IXTK200N10L2 power mosfets (T0264 package). I try to estimate the junction temperature of the...

Hello I design an electronic load, using IXTK200N10L2 power mosfets (T0264 package). I try to estimate the junction temperature of the mosfets, using an IR camera to measure accessible temperatures. Mosfets are directly mounted on a air-forced heatsink (Theta-sa around 0.08?C/W), with thermal grease. With the camera, I can access the temperatures of : - the heatsink near the mos...