Running AC induction motors from pulsed DC

Started by Julian Barnes in sci.electronics.design6 years ago 17 replies
PWM

Hi all, Is it possible to power an 50Hz or 60Hz single phase AC induction (asynchronous) motor from some form of pulsed DC - say like PWM or...

Hi all, Is it possible to power an 50Hz or 60Hz single phase AC induction (asynchronous) motor from some form of pulsed DC - say like PWM or some variant thereof? Thanks.


Motor controller

Started by en2 in sci.electronics.design7 years ago 7 replies
PWM

Hi ! I was planning on creating one motor controller for my crystalyte motor. Its three phase 1,5kw blcd motor. Can someone share ideas on...

Hi ! I was planning on creating one motor controller for my crystalyte motor. Its three phase 1,5kw blcd motor. Can someone share ideas on pwm design and or basic schematics ?


PWM modulation in function generators is rare! Siglent anyone?

Started by Mr.CRC in sci.electronics.design10 years ago 3 replies

Hi: So few seem to have this. I actually budgeted to buy me an Agilent 33522A for 3 grand a year ago, along with a DSO3000X series scope. ...

Hi: So few seem to have this. I actually budgeted to buy me an Agilent 33522A for 3 grand a year ago, along with a DSO3000X series scope. I balked at the generator since the ones I have at work have serious bugs. They have fixed them almost, but not perfectly. I know they will fix them fully if I send in new complain-o-grams, but I haven't had time to do that yet. Anyway, for $3k o...


Class D commercial audio amp

Started by N_Cook in sci.electronics.design5 years ago 65 replies

Using PWM input to a Si8244BB predriver soic. After the inductor HF cut filter, on the 8 ohm speaker load there is about 1.5V pk-pk 200Kz...

Using PWM input to a Si8244BB predriver soic. After the inductor HF cut filter, on the 8 ohm speaker load there is about 1.5V pk-pk 200Kz constant level of switcher waveform, is that normal? what sort of background level would be normal ?


MPS430 cordicPWM sine wave generator

Started by miso in sci.electronics.design9 years ago 18 replies
PWM

The eval kit is a whole $4.30 including shipping, and it comes 2nd day Fedex. > ...

The eval kit is a whole $4.30 including shipping, and it comes 2nd day Fedex. > http://e2e.ti.com/group/microcontrollerprojects/m/msp430microcontrollerprojects/609573.aspx The person coded the cordic, and then implemented the sine wave with PWM.


Any Tube Guys Here ?

Started by Anonymous in sci.electronics.design7 years ago 75 replies
PWM

Tube based PWM at about 150 kc. (hey, it's tubes so kc is right...) https://dl.dropboxusercontent.com/u/29948706/tube1.jpg The reason I...

Tube based PWM at about 150 kc. (hey, it's tubes so kc is right...) https://dl.dropboxusercontent.com/u/29948706/tube1.jpg The reason I depict R1 as going to the plate is because it technically must= . In this app the load might be on the ngative side. That is, like in a tot= em pole arraingement.=20 It's obvious what a screen grid does kinda, but I am not so sure. I am not = sure exac...


Anyone work with GSM &3G?

Started by Bob Sutton in sci.electronics.design10 years ago 7 replies
PWM

I am seeking specific information regarding the signal structure of GSM and 3G. Does anyone here work for a Telco, or is familliar with the...

I am seeking specific information regarding the signal structure of GSM and 3G. Does anyone here work for a Telco, or is familliar with the make up and comparative capabilities of these? In particular, I am interested in the types of modulation inherent to these standards which are technically available (utilized or not) for transmission of _analog_ signals, ie FM, PWM, etc. Bob Sutto...


Suggestions on how to eliminate 'click'

Started by Charlie E. in sci.electronics.design10 years ago 30 replies

Hi All, Ok, I have been bashing my head against the wall all day, again, and once more request my betters show me the correct path... Here is...

Hi All, Ok, I have been bashing my head against the wall all day, again, and once more request my betters show me the correct path... Here is the problem I have. I have been trying to improve the audio quality on my color readers. It presently uses ADPCM, which is decoded and used to adjust the bandwidth on a PWM output on my PIC24, fitered by a fourth order Sallen filter into my amplifi...


Assembler Code Question

Started by Anonymous in sci.electronics.design8 years ago 7 replies
PWM

Would anyone here be willing to have a look, maybe off-list, at an Assembler routine that was written for me several years ago? It is a five...

Would anyone here be willing to have a look, maybe off-list, at an Assembler routine that was written for me several years ago? It is a five channel sinewave generator using LUT's on a PIC micro. I am not a coder, but need to know how to make changes in stp1hi EQU and stp1lo EQU values in order to derive different frequencies. I also would like to know the definition of a "PWM factor...


GHz oscillator

Started by John Larkin in sci.electronics.design7 months ago 55 replies

What's a good way to make a, say 2 or 3 GHz sinewave oscillator? I don't need extreme accuracy, and I'd like maybe 1 volt p-p. I was thinking...

What's a good way to make a, say 2 or 3 GHz sinewave oscillator? I don't need extreme accuracy, and I'd like maybe 1 volt p-p. I was thinking a cheap MMIC with PCB delay line feedback. MiniCircuits VCOs are around $20, which isn't bad. The output would go into a PWM modulator and then an AC-coupled communications channel.


Dumpy filter

Started by bitrex in sci.electronics.design4 years ago 49 replies

Filtering 0-5V 1kHz PWM square wave to get ~1 volt to 10 volts DC output proportional to duty cycle, an LM386 as two-pole Sallen Key...

Filtering 0-5V 1kHz PWM square wave to get ~1 volt to 10 volts DC output proportional to duty cycle, an LM386 as two-pole Sallen Key "Busselworth" filter: Faster settling and better drive current than an RC filter, almost as cheap. It's not glamorous but gets the job done


Old HP 412a, Theory Of Operation

Started by Anonymous in sci.electronics.design5 years ago 3 replies
PWM

Accurate as hell, very high input resistance. Range that makes conventional VTVMs blush. They got four light bulbs in there and a wheel that...

Accurate as hell, very high input resistance. Range that makes conventional VTVMs blush. They got four light bulbs in there and a wheel that spins. I imagine it is PWM actually, what else ? But how the hell do they get the accuracy ? That old thing agrees with a Fluke 8846 (I think that's the model) which, while not a Keithley electrometer is pretty damn good. Sometimes I a


TI deadtime generator

Started by Piotr Wyderski in sci.electronics.design2 years ago 11 replies

It seems they took Win's circuit way too...

It seems they took Win's circuit way too carelessly: https://e2e.ti.com/blogs_/b/powerhouse/archive/2015/09/10/control-a-gan-half-bridge-power-stage- with-a-single-pwm-signal According to the schematic, they use SN75LVC2G14 as the Schmitt trigger. The datasheet says V_T+ is 2.2--3.7V (@5.5V), while V_T- is 1.4--2.5V and deltaV_T is 0.7--1.4V. This would be good enough for *some* deadtime i


Slowing solenoid action?

Started by Terry Pinnell in sci.electronics.design2 years ago 33 replies

Is it possible, perhaps using PWM, to slow down the action of a solenoid while still maintaining most of its force? By way of background, I'm...

Is it possible, perhaps using PWM, to slow down the action of a solenoid while still maintaining most of its force? By way of background, I'm considering a solenoid for pressing a rather firm button. The only one I have at present that can do so reliably is a 24V type that delivers its press too fast and too noisily. Lower voltage types (already owned or researched on ebay or Amazon) seem t...


motors geared together

Started by unk in sci.electronics.design5 years ago 5 replies
PWM

It's not uncommon for RC models to have two electric (brushed) motors geared together to one shaft. The motors are almost always controlled...

It's not uncommon for RC models to have two electric (brushed) motors geared together to one shaft. The motors are almost always controlled by (a pair of) some type of open- loop (no feedback) PWM driver. Can someone explain to me if, or if not why, the inevitable differences between motors and electronics do not result in the motors attempting to turn at different rates and wasting e...


PIC Micro Picky About Power Supplies

Started by Robert Wade in sci.electronics.design7 years ago 12 replies
PWM

I have a PIC 16F628-20 micro running code to generate two dial tones. It seems to be very fussy about how it is powered. Sometimes it...

I have a PIC 16F628-20 micro running code to generate two dial tones. It seems to be very fussy about how it is powered. Sometimes it starts on batteries, and sometimes not. On my lab supply, it puts out a steady PWM frequency, but with no modulation. Same goes with an LM7805. In all instances the voltage is 5V. I don't think it is the PIC chip, since it will operate under what it per...


a little filter

Started by John Larkin in sci.electronics.design8 years ago 51 replies

We make a box that can output a lot of fiberoptic logic signals, light on/off. One existing mode is PWM, where frequency is 125 MHz/N,...

We make a box that can output a lot of fiberoptic logic signals, light on/off. One existing mode is PWM, where frequency is 125 MHz/N, and "on" resolution is 1 ns. I have a customer who needs a remote analog signal, 0-1 volt, that he can update in a microsecond or two. He'd like 10 bit resolution. So I figured that an optical/electrical converter could drive a lowpass filter at the far...


SMPS housekeeping electronics power question

Started by Anonymous in sci.electronics.design9 years ago 4 replies

Could some electronics guru please clarify a bit ? How is power to the control electronics circuitry of an SMPS provided -- power for...

Could some electronics guru please clarify a bit ? How is power to the control electronics circuitry of an SMPS provided -- power for controller/PWM module ? Any hints, suggestions or pointers to relevant information would be helpful.


Data over battery line

Started by Marco Trapanese in sci.electronics.design10 years ago 21 replies

Hello, I need to transmit few bits on a cable connected to the battery of a motorbike. The communication must be bidirectional. Very very low...

Hello, I need to transmit few bits on a cable connected to the battery of a motorbike. The communication must be bidirectional. Very very low bit rate. The cable lenght is less than 2 m. I'm thinking about a quite high-frequency PWM (about 100 kHz) with a simple on-off modulation. Passive detector on receiver side with a comparator. Cost is the primary target thus I'd avoid to use...


Boost Converter Tutorial?

Started by Jim Thompson in sci.electronics.design10 years ago 68 replies

In the past I have designed boost converters in burst mode, with peak current control, but never with a PWM-controlled loop. Outputs: +5 @...

In the past I have designed boost converters in burst mode, with peak current control, but never with a PWM-controlled loop. Outputs: +5 @ 25mA, -5V @ 20mA Can someone point me to a tutorial? Thanks! [Don't point me to an off-the-shelf part. This has to go into a _custom_ chip... just a little thing... 1mm x 25mm :-] ...Jim Thompson -- ...