## Anyone Have Spice model for JFET IF400?

Started by in sci.electronics.design6 years ago 11 replies

Anyone Have Spice model for JFET IF400? It's only used as a diode in the discrete circuit I have been asked to model behaviorally, but it's...

Anyone Have Spice model for JFET IF400? It's only used as a diode in the discrete circuit I have been asked to model behaviorally, but it's the only model I haven't been able to find :-( ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Ana...

## Spice Diode Modeling of Forward Overshoot & Reverse Recovery

Started by in sci.electronics.design6 years ago 98 replies

Nothing like a PhD telling me something can't be done to get my solver genes working double-time... Over baby-back ribs at Firebirds this...

Nothing like a PhD telling me something can't be done to get my solver genes working double-time... Over baby-back ribs at Firebirds this afternoon I realized how to parameterize my method. But all the information I have is from "peer-reviewed" semi-BS IEEE papers. Would someone be so kind as to take data on something common like a 1N914... forward overshoot and reverse recovery at va...

## USB charger circuit

Started by in sci.electronics.design10 years ago 20 replies

I am working on a simple USB charging circuit. Normally, the 3.6V NiMH bat= tery is connected to the device via the NC contacts of a relay. ...

I am working on a simple USB charging circuit. Normally, the 3.6V NiMH bat= tery is connected to the device via the NC contacts of a relay. When conne= cted, a 5V relay switch the battery to charge via a diode. So, a fully char= ged battery is around 4.2V. As someone suggested, i will put a parallel R = & C to reduce the hold current of the relay.=20 Questions: 1. What is the minimum ...

## Semi OT: History of consumer radio designs

Started by in sci.electronics.design9 years ago 14 replies

I'm interested in how the design of consumer AM/FM radios has evolved over time, particularly since digital tuning/ PLL synthesizers came on...

I'm interested in how the design of consumer AM/FM radios has evolved over time, particularly since digital tuning/ PLL synthesizers came on the scene. Some early (1980?) PLL receiver schematics I've seen show the LC front end tank being tuned by a varactor diode. I'd imagine for several reasons one would want to eliminate the complexity of this kind of front end setup if at all pos...

## Apex HV opamp issues.

Started by in sci.electronics.design9 years ago 50 replies

Hi guys (and dolls), So if you read in JL's TI opamp thread, I am having noise issues in our laser diode. I turns out (I think) that the extra...

Hi guys (and dolls), So if you read in JL's TI opamp thread, I am having noise issues in our laser diode. I turns out (I think) that the extra noise is coming from my Piezo drive. The original circuit used a PA141 from Apex. (I can't find a schematic on-line, but I have a hard copy.) Several years ago this HV opamp went away and the recommended replacement from Apex was the PA314 http...

## dual-range TIA circuit

Started by in sci.electronics.design2 years ago

This is an improved version of the one in the X-chapters. The dumb summer should be smarter to optimize s/n. If we digitize V1 and V2 and do...

This is an improved version of the one in the X-chapters. The dumb summer should be smarter to optimize s/n. If we digitize V1 and V2 and do some tweaks, that should work. BFT25 is sadly EOL. Its c-b junction is about the best diode anywhere. I'll have to find a comparable part somewhere. Version 4 SHEET 1 1192 680 WIRE -16 -304 -64 -304 WIRE 32 -304 -16 -304 WIRE 288 -304 256 -304 ...

## Schottky diodes, reverse current and solar changers

Started by in sci.electronics.design1 year ago 13 replies

Hi all I am playing around with a solar lamp, pretty simple like this https://www.pinterest.com/pin/540150549038731182/ However I do not...

Hi all I am playing around with a solar lamp, pretty simple like this https://www.pinterest.com/pin/540150549038731182/ However I do not (yet) have D2. D1 in my case is a Schottky 1N5818, and my battery 7.2V I am surprised how much reverse current I can get through the diode. Without the solar cell, it does not turn on. There is enough current through D1 to the transistor to turn the wh...

## Aluminum-core PCB cost?

Started by in sci.electronics.design6 years ago 33 replies

I have a customer who wants me to do an extreme shrink of our semi-custom diode laser controller board, which leads to a lot of thermal...

I have a customer who wants me to do an extreme shrink of our semi-custom diode laser controller board, which leads to a lot of thermal issues. The obvious approach is an aluminum-core circuit board, but I've never used one. A few questions for the cognoscenti: 1. Can I get a 6- or 8-layer aluminum-core PCB? 2. How much more do they cost? 3. Any other constraints? Thanks ...

## Video monitors and CCD cameras.

Started by in sci.electronics.design12 years ago 29 replies

For one of our instruments, Diode laser spectroscopy, (http:// www.teachspin.com/instruments/diode_laser/index.shtml) We use a CCD camera and...

For one of our instruments, Diode laser spectroscopy, (http:// www.teachspin.com/instruments/diode_laser/index.shtml) We use a CCD camera and little TV to image the NIR laser spot and observe the Rubidium fluorescence. (Used to tune the laser to the correct wavelength.) So we didn=92t buy a lifetime supply of either the cameras or TVs and now they are both disappearing. (about a year...

## What happens if I connect a computer fan reversed?

Started by in sci.electronics.design5 months ago 13 replies

Hi, What happens if I connect a computer fan reversed? A brushless one. I know it has electronics to produce a rotating magnetic field from...

Hi, What happens if I connect a computer fan reversed? A brushless one. I know it has electronics to produce a rotating magnetic field from DC, but what happens if I reverse the connection? - nothing - the electronics self destruct - there is a reversed diode that shortcircuits the DC - the electronics detect the reversal and either keep working correctly or reverse the rota...

## Nice MCU for small jobs

Started by in sci.electronics.design5 years ago 96 replies

LPC804: 15 MHz Cortex M0+, 32kB flash, 4k RAM, 12-bit 2 us ADC with 1 LSB DNL, 10-bit DAC, the usual serial stuff, 20-TSSOP: 67 cents in...

LPC804: 15 MHz Cortex M0+, 32kB flash, 4k RAM, 12-bit 2 us ADC with 1 LSB DNL, 10-bit DAC, the usual serial stuff, 20-TSSOP: 67 cents in reels, dev board \$27. We're using it for a super-quiet diode laser controller where it will run the temperature control and automatic power control loops. I'll never use another ATmega. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principa...

## Pulse-powered current limiter

Started by in sci.electronics.design2 years ago 23 replies

Hi, I am experimenting with white LED COBs and wanted to power them from a constant current source while still having the PWM dimming...

Hi, I am experimenting with white LED COBs and wanted to power them from a constant current source while still having the PWM dimming capability. The current limiter should be located next to the diode and the lamp "interface" should be regular two wires. In other words, the current limiter should be capable of being powered from a +12V/open drain source with the PWM frequency of ~400H...

## Two bridge rectifiers on a centre tapped transformer?

Started by in sci.electronics.design7 months ago 50 replies

I have a centre tapped transformer I wanted to get the most power out of. Thinking a traditional full wave rectifier (just a diode on each side,...

I have a centre tapped transformer I wanted to get the most power out of. Thinking a traditional full wave rectifier (just a diode on each side, calling the centre tap 0V at the output) is only running current through one half of the secondary at a time, which is inefficient (think of P=i^2R), I thought about putting a bridge rectifier on each half, then connecting the result in parallel. I made...

## Isolating bridge rectifier

Started by in sci.electronics.design3 years ago 11 replies

I want to use the short audio output from my iPad to generate a brief 5V pulse for an Arduino circuit. I am using an existing pre-amp to take the...

I want to use the short audio output from my iPad to generate a brief 5V pulse for an Arduino circuit. I am using an existing pre-amp to take the roughly 200mv pk-pk ac to about 8V pk-pk. I thought Iâd follow that with a simple 4-diode bridge rectifier. The pre-amp and the Arduino circuit have a common ground rail. So is the correct method to take each of the pre-amp outputs

Started by in sci.electronics.design12 years ago 8 replies

Hi all, To build limiters that protect my analog input stages, I use for years the base-collector junction of transistors instead of simple...

Hi all, To build limiters that protect my analog input stages, I use for years the base-collector junction of transistors instead of simple diodes. This improves the SNR (the base-collector junction seems less noisy than the diode junction). It has become a reflex and now I am not able to find the justification again. And unfortunately, I did not found anything on this subject. Does anyo...

## Complementary ThermalTrak Power Transistors

Started by in sci.electronics.design9 years ago 10 replies

On Semi introduced in 2006 a series of complementary power transistors, called ThermalTrak. These come in five-lead TO-264 packages and use the...

On Semi introduced in 2006 a series of complementary power transistors, called ThermalTrak. These come in five-lead TO-264 packages and use the extra two pins for an integrated, isolated temperature-sensing diode. The transistors are reasonable parts, with 230 to 350V ratings, and with 30MHz fT. There are four sets of parts in the series, with pretty detailed datasheets, except, hah, l...

## Re: Diode -- pick and place

Started by in sci.electronics.design3 years ago

jlarkin@highlandsniptechnology.com wrote in news:nc0p6gtbikle25vufiusl1b0ond4i6imsf@4ax.com: > On Tue, 6 Apr 2021 08:20:09 -0700 (PDT),...

jlarkin@highlandsniptechnology.com wrote in news:nc0p6gtbikle25vufiusl1b0ond4i6imsf@4ax.com: > On Tue, 6 Apr 2021 08:20:09 -0700 (PDT), mkr5000 > wrote: > > > On Tuesday, April 6, 2021 at 11:06:44 AM UTC-4, > > DecadentLinux...@decadence.org wrote: > > > mkr5000 wrote in > > > news:c8557e23-95c8-4278...@googlegroups.com: > > > > On Monday, April 5, 202

## xor mixer

Started by in sci.electronics.design8 years ago 76 replies

I need a really low noise mixer, better than I can do with a diode ring mixer. The signals are ECL square waves, around 150 MHz, so I figure...

I need a really low noise mixer, better than I can do with a diode ring mixer. The signals are ECL square waves, around 150 MHz, so I figure the best mixer starts with a really fast XOR gate. The result is ECL, but I'm leery of the analog quality (noise and DC drift) of the raw gate output, so I was thinking that a differential pair could add some analog precision. https://dl.dropboxuser...

## Dealing with mains power transients

Started by in sci.electronics.design7 years ago 19 replies

I'm looking at protecting a power sense circuit from mains power transients, using a resistor and a zener diode. Spice says it works well,...

I'm looking at protecting a power sense circuit from mains power transients, using a resistor and a zener diode. Spice says it works well, but when the zener conducts, essentially the entire transient voltage appears across the resistor. A high voltage transient spike is likely to be very narrow, but I can find nothing to say I can put, say, 5000V, across a 1K resistor, even for a micro...

## Pokit Meter All-in-One Multimeter, Oscilloscope and Data Logger

Started by in sci.electronics.design2 years ago 5 replies

Radio Shack at it again: Wireless multimeter: measures AC/DC voltage, AC/DC current, resistance, continuity, diode polarity and ambient...

Radio Shack at it again: Wireless multimeter: measures AC/DC voltage, AC/DC current, resistance, continuity, diode polarity and ambient temperature. Oscilloscope: captures detailed voltage and current waveforms and provides FFT analysis. Logger: up to 6 months standalone data-logging Retractable Leads. App available for iOS and Android. Pinch and drag to zoom and analyse signals, and cursors...