Guitar MIDI controller/converter - bitrex?

Started by Don Y in sci.electronics.design10 months ago 25 replies

Advice on good ("respectable") candidates for the above? Not keen on a guitar-wannabe "instrument"... (Also, not keen on anything that will...

Advice on good ("respectable") candidates for the above? Not keen on a guitar-wannabe "instrument"... (Also, not keen on anything that will not be able to completely restore axe to original condition when no longer needed/wanted)


12v DC to 20v DC

Started by Anonymous in sci.electronics.design11 years ago 10 replies

Anyone has a DC-DC (12v -> about 20v at 4 to 8 A) converter schematic that proved reliable?

Anyone has a DC-DC (12v -> about 20v at 4 to 8 A) converter schematic that proved reliable?


Frequency-to-voltage converter, PLL with an AD650

Started by Jean-Pierre Coulon in sci.electronics.design8 years ago 10 replies

I tried to reproduce fig.22, p.17 of the datasheet but the output voltage is always about +13 V The VCO alone (like fig.12) works up to about...

I tried to reproduce fig.22, p.17 of the datasheet but the output voltage is always about +13 V The VCO alone (like fig.12) works up to about 1 MHz provided the input voltage is in the [-12:0] range. Has anybody a working schematics? Regards, -- Jean-Pierre Coulon


Ultra-efficient bucks

Started by Piotr Wyderski in sci.electronics.design3 years ago 21 replies

I have been recently working on my current-fed converter. Its only advantage is that it works, but not exactly as advertised. This circuit...

I have been recently working on my current-fed converter. Its only advantage is that it works, but not exactly as advertised. This circuit deserves a separate autopsy thread, but the scope for some reason doesn't like the pen drives I have at hand. So it would be pointless to start without some screen dumps indicating where the problems are. I would like to evaluate it against some alte...


Original Royer paper

Started by Klaus Kragelund in sci.electronics.design11 years ago 13 replies

Hi I am looking for the original paper from 1954 that George Royer did on his Royer converter circuit: "Transistors as on-off switches in...

Hi I am looking for the original paper from 1954 that George Royer did on his Royer converter circuit: "Transistors as on-off switches in saturable-core circuits" in Electrical Manufactoring Anyone know where I can get this? Regards Klaus


Bidirectional LLC

Started by Piotr Wyderski in sci.electronics.design2 years ago 6 replies

Hi, Every converter with synchronous rectification should be capable of bidirectional operation. But there seem not to be any practical...

Hi, Every converter with synchronous rectification should be capable of bidirectional operation. But there seem not to be any practical realisations of bidirectional LLC, except for some vague conference papers. And even then it is not a pure LLC, but a CLLC or split-rail LLC. Why? Best regards, Piotr


A new spin on MRI

Started by Jan Panteltje in sci.electronics.design12 months ago 2 replies

A new spin on MRI: https://www.sciencedaily.com/releases/2021/12/211213121832.htm Using a frequency converter from 17 MHz to 64 MHz can make...

A new spin on MRI: https://www.sciencedaily.com/releases/2021/12/211213121832.htm Using a frequency converter from 17 MHz to 64 MHz can make normal MRI equipment show sodium-23 ions.


Turbo Royer/Baxandall in boost configuration

Started by bitrex in sci.electronics.design1 year ago 62 replies

Is it possible to take your standard Baxandall and tap the capacitor, take an aux winding off the secondary and feed a somewhat higher DC...

Is it possible to take your standard Baxandall and tap the capacitor, take an aux winding off the secondary and feed a somewhat higher DC voltage to the cap (through the usual two-diode supply handoff arrangement), and use it to feed the gate drive to the transistors as well, which would be clocked rather than self-oscillating. The goal would be to have a quiet step-up converter that co...


isolated DC/DC converter

Started by John Larkin in sci.electronics.design11 years ago 189 replies

This http://www.panoramio.com/photo/61564837 might work for powering a thing I'm doing. I can use a standard cheap Coiltronix dual-coil...

This http://www.panoramio.com/photo/61564837 might work for powering a thing I'm doing. I can use a standard cheap Coiltronix dual-coil inductor as the transformer. The complementary emitter followers will have no shoot-through and can have controllably slow switching edges, since they will just follow the base drive. Anybody got ideas for the base driver device? Ideally it would be s...


300V power supply.

Started by George Herold in sci.electronics.design5 years ago 40 replies

Hi all, So I'd like to make a 300 V supply. I don't really want to start from the AC line. So I've been looking for a DC-DC converter...

Hi all, So I'd like to make a 300 V supply. I don't really want to start from the AC line. So I've been looking for a DC-DC converter solution. I started here, (of course) http://www.analog.com/media/en/technical-documentation/application-notes/AN118fb.pdf Figure 13 looked nice. I then priced a pico 32195 transformer. ~$100! Ouch! (maybe I can find a cheaper one.) I then was tr...


A flyback based on the new Infineon SiC

Started by Piotr Wyderski in sci.electronics.design2 years ago 2 replies

Some time ago James Arthur sent here a notification about the IMBF170R1K0M1XTMA1 SiC MOSFET. I have just re-prototyped one of my wide input...

Some time ago James Arthur sent here a notification about the IMBF170R1K0M1XTMA1 SiC MOSFET. I have just re-prototyped one of my wide input range flybacks, and the results are excellent. The performance is comparable to the one with the 1700V C2M Cree part, but the converter's structure is much simpler, which is good for reliability. Thanks, James. Best regards, Piotr


speaking of substrate diodes...

Started by Anonymous in sci.electronics.design1 year ago 2 replies

leads to this one... https://www.dropbox.com/s/cgaxalnn3hhf315/RRIO_Logamp.jpg?raw=1 where we use the substrate diode of a RRIO opamp as a...

leads to this one... https://www.dropbox.com/s/cgaxalnn3hhf315/RRIO_Logamp.jpg?raw=1 where we use the substrate diode of a RRIO opamp as a logarithmic current-to-voltage converter. There are better ways to do this, but maybe none so cute. -- Father Brown's figure remained quite dark and still; but in that instant he had lost his head. His head was always most valuable whe...


klunky pc board

Started by Anonymous in sci.electronics.design3 years ago

https://www.dropbox.com/s/20fepk4db4rfkd2/P903_Range_Switch.jpg?raw=1 This accepts four transformer secondaries on the left, faston...

https://www.dropbox.com/s/20fepk4db4rfkd2/P903_Range_Switch.jpg?raw=1 This accepts four transformer secondaries on the left, faston tabs, and switches the windings with relays, in four combinations of series and parallel. Output is on the right, both fastons and a pluggable Phoenix. There's an isolated delta-sigma ADC, with a dc/dc converter, to snoop the final output voltage. 4 layers,...


Reducing SMPS noise

Started by Anonymous in sci.electronics.design6 years ago 43 replies

I'm working on a PCB that contains nearly 30 resistors in a ladder configuration, each step switched in or out by a SMT solid state relay. It's...

I'm working on a PCB that contains nearly 30 resistors in a ladder configuration, each step switched in or out by a SMT solid state relay. It's essentially a decade box for a specific application. The relays are controlled by a micro and all is powered by a boardmount enclosed CUI AC/DC switching converter, supplying up to 400mA. The resistors are electrically isolated from the SM


Groundplane under SMPS power inductor

Started by John Devereux in sci.electronics.design7 years ago 48 replies

I have seen designs where there is a cutout in the groundplane under the power inductor in e.g. a buck converter. Inductor is nominally...

I have seen designs where there is a cutout in the groundplane under the power inductor in e.g. a buck converter. Inductor is nominally a "shielded" one. I assume it is to prevent some kind of "shorted turn" effect? What do you think? Might a continuous plane be better? It could help to shield any field leakage and reduce emissions and circuit noise. I am asking generally, but say 1...


dc/dc converter ckt

Started by John Larkin in sci.electronics.design6 months ago 16 replies

I'm designing another 3-phase PM alternator simulator, and I need a roughly +-60 volt floating power supply. It will feed three PWM half-bridges...

I'm designing another 3-phase PM alternator simulator, and I need a roughly +-60 volt floating power supply. It will feed three PWM half-bridges to make the three output phases. Here's my first pass at the dc/dc thing. https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1 Those Coilcraft planar transformers are radical. 300 watts, surface mount, under a cubic inch. They have a ...


Coupled Inductors--how coupled is coupled?

Started by Phil Hobbs in sci.electronics.design7 years ago 45 replies

So in the continuing saga of cotton spark detection, I need to make an isolated 2-output DC-DC converter to power an RS-485 link and a small...

So in the continuing saga of cotton spark detection, I need to make an isolated 2-output DC-DC converter to power an RS-485 link and a small SBC--about 2W altogether. This isn't a terribly low-noise application, so I was thinking about using the Bourns SRF0703-471M "coupled inductor" as a flyback. The question is, what's the coefficient of couping? There's no way to find out from the ...


H-bridge IC

Started by Winfield Hill in sci.electronics.design7 years ago 11 replies

I'm looking for a small, inexpensive H-bridge, or full-bridge IC, including MOSFET switches, for a forward-converter application. (My old...

I'm looking for a small, inexpensive H-bridge, or full-bridge IC, including MOSFET switches, for a forward-converter application. (My old favorite HIP4080 series has 20 pins and requires external FETs.) Most of the ICs with internal switches that I've found are meant for driving motors, and seem to have slow switching speeds. 40 volts and 2 amps are my minimum requirements. The LMD18200 ...


100mV DC supply

Started by Marke in sci.electronics.design5 years ago 32 replies

Hi All, I have a need to generate +100mV DC to drive a load which is capable of sourcing up to ~50mA but will typically see high impedance....

Hi All, I have a need to generate +100mV DC to drive a load which is capable of sourcing up to ~50mA but will typically see high impedance. Easily available I have a clean 24V source and 208VAC. My intent is to drop from 24V to ~1.8V using a buck converter then follow it up with a 1.0V precision shunt (ADR510 or other) followed by a 9:1 precision resistor divider. Buffer the 100mV


Looking for fast-ish sot-89 NPN

Started by Gerhard Hoffmann in sci.electronics.design7 months ago 7 replies

Hi, I'm trying to build a 2-200 MHz isolation amplifier. For 13 dBm I need abt. 120 mA peak current, 70 mA quiescent. The circuit is a...

Hi, I'm trying to build a 2-200 MHz isolation amplifier. For 13 dBm I need abt. 120 mA peak current, 70 mA quiescent. The circuit is a voltage to current converter, followed by a double cascode. 2N3904 is too slow, BFQ19S is too hot, it would do 1 GHz, but brings me negative input impedance, gain peaks and so on. I'm playing with the usual ferrite beads, but that does not bring com...