So is there any simple circuit using conventional NPN and PNP transistors? I've seen this...

So is there any simple circuit using conventional NPN and PNP transistors? I've seen this circuit http://sub.allaboutcircuits.com/images/quiz/02139x02.png in _Sourcebook of Electronic Circuits_, but it doesn't really work- it latches but does not release when used in a relaxation oscillator. Perhaps it did work with lower gain transistors. -- /* jhallen@world.std.com AB1GO */ ...

I've changed the circuit a bit - essentially taking out bits that didn't add value - but I did change the Sallens and Keys filter to one with a...

I've changed the circuit a bit - essentially taking out bits that didn't add value - but I did change the Sallens and Keys filter to one with a bit of gain that gives you a maximally flat time delay with standard value components. The performance is marginally better. http://sophia-electronica.com/BillsBaxandall.html -- Bill Sloman, Sydney

In terms of battery life, and assuming the same brand of Alkaline battery, is it more efficient to use a 9V battery or 2 AAA cells...

In terms of battery life, and assuming the same brand of Alkaline battery, is it more efficient to use a 9V battery or 2 AAA cells with something like the TL496 converter pictured here. http://www.electroschematics.com/6788/3v-to-9v-dc-converter/ If not, what is the approximate difference either way? The circuit involved is a test audio oscillator. Would be nice if they made mor...

These look great, very high Q. I'm thinking about a 50 or maybe 100 MHz Colpitts oscillator PLL. http://www.coilcraft.com/1515sq.cfm I...

These look great, very high Q. I'm thinking about a 50 or maybe 100 MHz Colpitts oscillator PLL. http://www.coilcraft.com/1515sq.cfm I wonder if the thermal expansion tempco of the FR4 board will stretch the coil and change its native tempco. FR4 is variously cited as being around +5 to +17 ppm/K, which isn't bad. That might even reduce the tempco of the inductor. I also wonder how ...

https://www.dropbox.com/sh/tgu2ozch3rbgglk/AABI3U3_iexb69UHWoRIzm-Ma?dl=0 Interesting. The high junction drops might be the SiGe, or just...

https://www.dropbox.com/sh/tgu2ozch3rbgglk/AABI3U3_iexb69UHWoRIzm-Ma?dl=0 Interesting. The high junction drops might be the SiGe, or just the tiny junction size. It would make a decent 0.3 pF 13 volt diode. I might make an oscillator and evaluate phase noise/jitter. An x-ray would be cool. We need a high-res xray machine. -- If a man will begin with certainties, he shall e...

Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 signal generator? A customer is testing a PLL that I designed. The PLL is...

Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 signal generator? A customer is testing a PLL that I designed. The PLL is designed to go into the far sub-Hz bandwidths, and they're having trouble getting it to lock onto the 15kHz signal from a Wavetek 273. I've got it running off of a crystal oscillator divided down and made into a sine wave, and it's perking along ...

I have been tasked with designing a piezoelectric actuator driver at its resonant frequency. This is to replace an arrangement where the sine...

I have been tasked with designing a piezoelectric actuator driver at its resonant frequency. This is to replace an arrangement where the sine wave source is a function generator chip (the obsolete XR-2206) that must be individually tweaked on a unit, by unit basis, to match the crystal?s resonant frequency. The crystal is used as an actuator to vibrate a mirror used in a laser syste

https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 I think the frequency should settle down to 1/(10*Tpd) but it...

https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 I think the frequency should settle down to 1/(10*Tpd) but it doesn't. We might do some pcb footprint tests for the tiny EPC fets, and I thought a board with a lot of ring oscillators would be a good way to test for good soldering. The EPC data sheet recommends a tiny solder-mask-defined pad arrangement that th...

Analog Devices makes some nice PECL comparators, but the data sheets are old and iffy, and there don't seem to be any Spice models. It...

Analog Devices makes some nice PECL comparators, but the data sheets are old and iffy, and there don't seem to be any Spice models. It was raining and snowing and I couldn't go skiing, so I did a behavioral model. I plan to use one of these to make a pretty good 500 MHz oscillator, so I wanted to get it mostly right. Jim's TANH thing is a nice way to make a saturating stage. The open-emit...

I want to divide a 32768 Hz crystal frequency by 20 to get a stable frequency for a component bridge. I could use a 4017 and half a a 4013 (sorry...

I want to divide a 32768 Hz crystal frequency by 20 to get a stable frequency for a component bridge. I could use a 4017 and half a a 4013 (sorry about these ancient devices, but they are still good for some things), but I would have to add something to make the crystal oscillate unless there is a way to use the other half of the 4013 to make the oscillator. I also looked at using j

Anybody have one of...

Anybody have one of these? https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv =0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25 I'll have my new 150 MHz Colpitts LC oscillator test board in a week or so, and I need a modestly good frequency counter for testing. We usually buy some high-end Keysight counter/timer for

A recent copy of the IEEE Spectrum included this...

A recent copy of the IEEE Spectrum included this article https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. And it is an Australian development ... -- Bill

I've up-dated my website to add a circuit diagram, some comment on it, and the text from the corresponding LTSpice .asc...

I've up-dated my website to add a circuit diagram, some comment on it, and the text from the corresponding LTSpice .asc file. http://sophia-electronica.com/BillsBaxandall.html The circuit produces a balanced pair of 1V rms 17kHz sine waves. The LTSpice simulation suggests the third harmonic content is about 60db below the fundamental, and the fifth harmonic is even smaller. It's not a par...

I have a trick on-topic question, looking for possibilities for candidates for a 16-pin SMD device that has these pin outs identified so...

I have a trick on-topic question, looking for possibilities for candidates for a 16-pin SMD device that has these pin outs identified so far: 1 & 16 - RC oscillator 4 - ground 7 & 8 - drivers for a "H" style MOSFet set of four transistors that between them generate a modified sine wave running at 60Hz and 120V. So it is NOT a TI SG3524/3525 chip. The MOSFets generate the pow...

Dear All, I am building a PWM Sine Wave Inverter using H-Bridge IGBT Configuration. The inverter has the following stages: 1. A Sine Wave...

Dear All, I am building a PWM Sine Wave Inverter using H-Bridge IGBT Configuration. The inverter has the following stages: 1. A Sine Wave Oscillator 2. An unity gain inverting amplifier to generate inverted sine wave 3. A Triangular wave generator 4. Two Sets of Comparators to generate PWM waveform for positive and negative cycles 5. Two Half Bridge IGBT Drivers to generate A and A' s...

Not actually a Hartley, bacause the Ls are not coupled. Version 4 SHEET 1 1220 836 WIRE 528 112 288 112 WIRE 288 144 288 112 WIRE 288 272...

Not actually a Hartley, bacause the Ls are not coupled. Version 4 SHEET 1 1220 836 WIRE 528 112 288 112 WIRE 288 144 288 112 WIRE 288 272 288 224 WIRE 528 288 528 112 WIRE 400 368 288 368 WIRE 480 368 400 368 WIRE 400 416 400 368 WIRE 288 528 288 368 WIRE 400 560 400 496 WIRE 432 560 400 560 WIRE 528 560 528 384 WIRE 528 560 496 560 WIRE 400 608 400 560 WIRE 528 656 528 560 WIRE...