hybridfree/eevblog-posts huggingface dataset:
Amplitude control for AD9833 function generator - Page 1
Forum section: electronics / beginners

author: golf32
author_rank: Regular Contributor
timestamp: January 22, 2021, 07:07:19 pm
content: Hi, I've been looking into building a function generator based on an AD9833 DDS generator. The specs I want to hit are:0-12.5MHzSin, Square, Triangle3-12v amplitude-9-9v DC offsetI don't think these specs are too hard to meet, and I have most of the design fleshed out, as there is a lot of prior work with this chip.The one part I am having problems with is amplitude control. Most designs use a potentiometer to vary the gain of the output amp, but I want to try and add digital control. I've explored many ways of varying the gain, but this does not seem to be the right approach.Instead, I think the best way to go about it is to have a fixed, high, gain and to attenuate the signal to vary the output. I've seen many variable attenuator building blocks, but I can't get any of them to simulate correctly. Any help would be great, Thanks.

author: HB9EVI
author_rank: Frequent Contributor
timestamp: January 22, 2021, 09:38:03 pm
content: direct control over the amplitude is not possible on the AD9833, potentiometer, also digital ones I'd skip on MHz-frequencies; also 12.5MHz is far away from being feasiblethe AD9834 is a much better choice for this project; it can be slightly overclocked with 80MHz, 12.5MHz is possible to reach; the amplitude control can be done over the Iset pin with a DAC controlled current source. for the different wave forms it makes sense to switch a LPF for the sine signalfor the DC offset, you find here a simple sketch how to get a bipolar voltage from an unipolar voltage like a DAC:https://www.ti.com/lit/pdf/slau525I did basically the same with a AD9850, just without tri/squ
Amprobe 34XR-A - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: March 09, 2010, 05:24:14 am
content: Hello, I am looking for buy this multimeter. What do you think about this model?. Thankshttp://amprobe.com/cgi-bin/pdc/viewprod.cgi?pid=2147&tid=1&type=elecExcuse me for my english, is really bad. Regards from Argentina

author: EEVblog
author_rank: Unknown
timestamp: March 09, 2010, 06:09:14 am
content: Looks like a good and very usable basic 4000 count meter.Depends entirely on what price you get it, and what your needs are.Dave.

author: Unknown
author_rank: Unknown
timestamp: March 09, 2010, 09:07:28 am
content: Thank you Dave for the rapid response. The electronics is a hobby for me. I like Fluke but is very expensive in my country and I think that I will never use all his functions.I was looking too for Amprobe 37XR-A, but the capacitance range is short. What do you think about my options?. 34XR or 37XR(more expensive)?.Thanks and regardsPablo

author: EEVblog
author_rank: Unknown
timestamp: March 09, 2010, 10:57:56 am
content: The 37XR has a more useful cap range than the 34XR, its goes down to 40nF range, two ranges lower than the 34XR at 4uF.Unless you are into measuring really big cap values that is.The 37XR has inductance vs the temperature on the 34XR, your choice which is more important to you. Temp is pretty darn useful for all sorts of things.The 37XR is of course 10000 count and better accuracy, 0.1% vs 0.5%, that's why you pay more.But the 34XR looks like a very useful and good meter that will serve you well I'm sure. I don't think you can go wrong with it.If your budget is very limited though, Amprobe are not the cheapest on the market, they are actually owned by Fluke after all. But you do get what you pay for.Dave.
Amprobe AM-510 Test Leads - Removable Safety Caps? - Page 1
Forum section: electronics / beginners

author: Unadan
author_rank: Contributor
timestamp: July 02, 2017, 06:20:07 pm
content: Just got my Amprobe AM-510 in earlier today. I'm a total newb so please be gentle! The test leads that came with the unit have "safety caps" near the tips. If I want to expose more of the metal of the test leads can I remove the safety caps by just popping them off? They don't seem to unscrew but the caps do loosely rotate around the metal leads. How do they come off? Or are they supposed to always be installed?

author: Unadan
author_rank: Contributor
timestamp: July 02, 2017, 06:49:46 pm
content: Disregard I figured it out.

author: alm
author_rank: Super Contributor
timestamp: July 02, 2017, 08:13:43 pm
content: To prevent the next person who has that problem from doing a search, finding your thread and then being frustrated by the lack of a solution, could you post it?

author: Unadan
author_rank: Contributor
timestamp: July 02, 2017, 08:18:25 pm
content: Yes - I watched a couple of Youtube videos concerning differing test leads and discovered that the safety caps simply just pull off from their base thus exposing more of the metal of the lead itself. There is a small indent in the larger bottom barrel of the safety cap that holds it in place. You have to pull relatively hard to get them off.Quote from: alm on July 02, 2017, 08:13:43 pm
Amprobe TMD-56 Doubt - Page 1
Forum section: electronics / beginners

author: raglo
author_rank: Newbie
timestamp: September 11, 2022, 01:50:33 am
content: Hi,Apologies for the very basic and rather odd question. I just received the Amprobe TMD-56 and while it works fine the package wasn't sealed and was really dusty. Seems like it has been in storage for a years . The sticker on the back was dated 2021 but on peeling it off I found that it was covering another sticker that said manufactured in July 2015. Is this something I should be concerned about or does it not matter for a device like this? Should I be getting a replacement is my question?

author: raglo
author_rank: Newbie
timestamp: September 13, 2022, 01:23:59 am
content: BUMP

author: raglo
author_rank: Newbie
timestamp: September 14, 2022, 03:26:05 am
content: Can someone please help me
Amps AC reading - Page 1
Forum section: electronics / beginners

author: HomerA
author_rank: Contributor
timestamp: February 10, 2015, 03:37:04 pm
content: Hi all,Another Noob question here.What should a multimeter (fluke 87) show when there are no leads plugged in and the dial is set to Amps AC? Would a reading of 0.013 indicate an out of calibration (or faulty) meter?Many thanksAlan

author: Zero999
author_rank: Super Contributor
timestamp: February 10, 2015, 03:44:34 pm
content: That measurement seems reasonable given that there will be some noise pick up if nothing is connected to the meter.

author: HomerA
author_rank: Contributor
timestamp: February 10, 2015, 03:50:14 pm
content: thanks Hero999, gives me some reassuarance :-)

author: mij59
author_rank: Frequent Contributor
timestamp: February 10, 2015, 04:00:47 pm
content: Tested my Fluke 87V, goes very very slow to zero.

author: HomerA
author_rank: Contributor
timestamp: February 10, 2015, 04:03:54 pm
content: thanks mij59. I will check that it goes to zero. :-)

author: electr_peter
author_rank: Unknown
timestamp: February 10, 2015, 04:08:42 pm
content: Check DMM AC current specifications. TRMS meters have higher offset with no input connected on AC voltage and AC current.

author: Zero999
author_rank: Super Contributor
timestamp: February 10, 2015, 04:14:52 pm
content: Have you tried short circuiting the input terminals with a very short piece of wire?

author: HomerA
author_rank: Contributor
timestamp: February 10, 2015, 05:40:42 pm
content: Thanks electra_peter.No not tried that Hero999. Will give that a go. Don't measure AC amps that offen, more electronics. But just wondered if it meant something was going out of kilter.Thasnk all :-)

author: retiredcaps
author_rank: Super Contributor
timestamp: February 10, 2015, 08:53:06 pm
content: This topic was discussed.https://www.eevblog.com/forum/chat/fluke-87v-non-zero-current-reading/
amps in cell towers - Page 1
Forum section: electronics / beginners

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 11, 2019, 07:06:39 am
content: What RF transistors do they employ in those pole or other shaped cell tower radio transmitters? Maybe someone here can post whats inside, they likely have very useful power parts.

author: oPossum
author_rank: Super Contributor
timestamp: May 11, 2019, 09:04:53 am
content: Several teardown videos of cellular equipment by forum member madsbarnkobhttps://www.youtube.com/channel/UCSukTlgTEWiL-sl0UeYeJvQ/videos

author: Nitrousoxide
author_rank: Regular Contributor
timestamp: May 20, 2019, 03:04:18 pm
content: LDMOS n-type transistors are fairly common in power amplifier design. Typically these are done on a silicon process, but you can get ones made on GaAs and GaN (or your preferred flavor).You may sometimes even find that there are two N-type devices in the single package. This is convenient as it allows for Doherty, balanced or push-pull configurations.I know Gallium Nitride (GaN) is seeing increasing use in DC-DC converters due to their lower loss and higher breakdown voltages (they are also direct bandgap compared to indirect for silicon). However, they are a pain to control as they are depletion mode devices.
AMS1117 (adjutable version) as a constant current regulator ? - Page 1
Forum section: electronics / beginners

author: cosmicray
author_rank: Frequent Contributor
timestamp: November 29, 2024, 02:45:05 pm
content: Is there any reason why the AMS1117 (adjustable version) can't be used for a constant current regulator (in the same basic circuit as a LM317L) ?My maximum voltage drop across the CC will be 5v (sometimes as low as 1.5v) and the current draw is nominally 55 mA. Based on the datasheets, the AMS1117 has the same adjustment pin voltage as the LM317L, has better thermals, and a higher maximum current (although I do not expect to ever go above 110 mA).Package for the AMS1117 is SOT-223 vs SOP-8 for the LM317L.datasheethttp://www.advanced-monolithic.com/pdf/ds1117.pdf

author: magic
author_rank: Super Contributor
timestamp: November 29, 2024, 04:00:04 pm
content: Stability could possibly be an issue, because 1117 are normally supposed to work with a capacitor on the output. Maybe it would still work with a capacitor between OUT and ADJ (across the current setting resistor), but I don't know. Differences between vendors possible..

author: cosmicray
author_rank: Frequent Contributor
timestamp: November 29, 2024, 09:13:34 pm
content: One of the issues I have run into today is that across five different datasheets for the (very) generic AMS1117, I have observed four different Absolute Maximum Ratings for the input voltage. They are 9v, 12v, 15v, and 30v. Other than the 9v, the others might be usable. Then I read about the problem with the generic Chinese AMS1117 crop, and that they mostly do not implement over-current graceful shutdown. While I'm still willing to use the xxx1117 style of chip, it will not be the AMS and/or it will come from a reputable distributor.

author: magic
author_rank: Super Contributor
timestamp: November 30, 2024, 11:19:24 am
content: I guess they save a penny by making the transistors smaller and incapable of surviving 30V. There is certainly a market for that and they still call it "1117" because that's what people search for.I have heard that somebody in China even makes fixed output, very low dropout P-ch CMOS regulators which are branded "1117" despite being nothing like the real thing.Whatever gets you the attention of designersTI sells a CMOS opamp which they call TL072H.
AmScope SE400 purpose of metallic tool - Page 1
Forum section: electronics / beginners

author: todorp
author_rank: Regular Contributor
timestamp: January 14, 2021, 03:09:22 pm
content: Hi all, I just received my brand new SE400 microscope. In the package there is a metallic tool outlined in red in the attached picture.Can someone explain what is the purpose of this "wrench"?! The manual does not mention it at all...Thanks a lot,Tod

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2021, 04:08:32 pm
content: Page 8 of the manual lists it as “tension adjustment wrench”. But it doesn’t refer to using it, even in the troubleshooting steps on focus tension...

author: todorp
author_rank: Regular Contributor
timestamp: January 14, 2021, 04:27:43 pm
content: Quote from: tooki on January 14, 2021, 04:08:32 pmThanks for the tip. I looked up the exact name on google and found an answer:https://www.amscope.com/how-to-use-microscopesection "Adjusting Focus Tension".Again, thanks a lot,Tod
An all new kit complete DC - >340 MHz RF test bench for under $400 US - Page 1
Forum section: electronics / beginners

author: rhb
author_rank: Super Contributor
timestamp: August 13, 2021, 01:10:52 am
content: I'm putting together a field day RF bench in a waterproof case. In the process I acquired a nanoVNA, several tinySAs and an Owon HDS272S. The HDS272S is a 70 MHz dual channel DSO, 25 MHz BW AWG and 4.5 digit DMM which sells for about $180 US. The interface is klunky, but the unit is competent and I have not found a single bug. Getting the combination of a DSO, AWG and DMM of that performance for $180 is quite a deal.The HDS272S is targeted at the automotive market. In that market, form factor dominates over adjustment aesthetics. A mechanic is just going to hook it up and hit "autoset". He's following a manual and these were developed for that market. I can't imagine a normal DSO surviving an auto shop for more than a week.Of course, there are all manner of accessories in the form of cables, adapters, etc which are often not cheap. But still, <$400 for an RF SG, SA, VNA, DSO, AWG, DMM, LCR/transistor tester and a diode noise source is a huge boon to the radio hobbyist. That's about 2 weeks take home flipping burgers. It's quite affordable. There has never been a better time to experiment with radio. In the last 30 years we've had a 1000x drop in cost for basic T&M kit.There are a lot of counterfeit nanoVNA and tinySA units on the market, so buying from a known distributor is a good idea. In the US R&L Electronics has been my source. I do have an ebay black "worst" nanoVNA copy and frankly, it's amazingly usable. There is some ambiguity about testing methods as some tests have found no difference. I think the creators should be paid. I already had an HP 8753B/85046A so I wasn't expecting much for the low price I paid. IIRC <$40. I was surprised and started investigating the device.Then the tinySA appeared in the same form factor.And all of it makes a nice piece of field day kit when you get your MSEE and get better gear ;-)The el cheapo bench recommendation:HDS272SnanoVNA H2x tinySA (source and receiver)BSIDE ESR02 Prothe not BG7TBL diode noise source from Chinaa couple of $6 Harbor Freight DMMsHave Fun!Reg

author: Renate
author_rank: Super Contributor
timestamp: August 13, 2021, 06:03:07 pm
content: Not bad, but you need some links:https://www.tinysa.org/wiki/https://nanovna.com/Please correct me if I'm wrong.
An alternative to LTC2954 chip that is available in China - Page 1
Forum section: electronics / beginners

author: anda3243
author_rank: Contributor
timestamp: April 13, 2022, 12:23:27 pm
content: Hello EEV forum.I am designing a board for a battery powered product. To preserve the battery, I want to incorporate a latching circuit.And I found this little nice chip LTC2954. It is a latch circuit, and can provide an interrupt signal to the MCU.https://item.szlcsc.com/608433.htmlI would like to use this chip instead of designing the circuit from separate components because of space requirements (especially if I can use the DFN package). Also, nice to use something ready made.It seems that in US/Europe this chip is kinda pricey, 2 to 3 USD.And I have not been able to find any China made alternatives. Or similar chips from other US or Europe manufacturers. This LTC 2954 is from AnalogDevices.Any suggestions for similar alternative chips are very welcome.

author: anda3243
author_rank: Contributor
timestamp: April 13, 2022, 01:28:14 pm
content: The man explains what a latching circuit is. Would be nice to find some ready made chip for that sweet sweet space saving.
An LDR based motion sensor - Page 1
Forum section: electronics / beginners

author: ledtester
author_rank: Super Contributor
timestamp: September 21, 2023, 06:22:04 pm
content: found this interesting so I thought I'd tell other people about it...I happened across this video which goes through the design of a motion sensor based on an LDR:Motion Detector without PIR module! Analog circuit Explained - Electronic Wizardhttps://youtu.be/9axYfWQQdnoIt does a good job of incrementally developing the circuit and troubleshooting the problems encountered along the way. Attached is the final schematic. Overall it looks like a fun circuit to breadboard up and play with -- in the video the author says he could "play with it all day".In researching the circuit I found it is also known as a "data slicer" which has applications in handling Manchester encoded signals. Here's a blog post in which one person compares the data slicer to other op-amp circuits in finding a "pulse" in a signal:https://electronut.in/designing-an-op-amp-circuit-to-detect-ldr-pulses/

author: StillTrying
author_rank: Super Contributor
timestamp: September 22, 2023, 09:28:29 pm
content: Reminds me of an idea I had 5 years ago to make a 'yard intruder detector', perhaps.Using 2 small LDRs very close together behind a 2 or 3 cm diameter lens the idea was that it could be inside looking out of a window. Two LDRs in series so that it automatically adjusts from daylight to darkness, in theory.After spending an hour matching 2 LDRs in room light, I gave up on the idea.

author: RJSV
author_rank: Super Contributor
timestamp: September 23, 2023, 04:55:57 am
content: Drug store toys Dept. sold me my Halloween themed toy that used an LDR motion detect, (and without an IR light nearby). The toy was a fake 'instant' Polaroid style 'camera' that blinked a strobe 'flash', then opened a slide drawer, supposedly with Polaroid single photo.Assuming most was done in software, flexible code could use the analog values to detect various changes in light level, for a robust motion detection function.If I had written it, the code would basically figure out the current average light levels, and monitor for faster changes, while keeping track, as general light levels slowly shift.
An outside light is tripping the breaker, which one is it of six? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: September 16, 2020, 08:45:58 pm
content: UK 240V 50Hz mains. 6 outdoor lights on a light dependent sensor so they all come on at dusk and go off at dawn. Recently they haven't been coming on. Distribution box shows the breaker for them has tripped out. I rest it today and when it grew dusk it tripped again. The main RCD is not tripping, so I suspect a shorted bulb or holder. Some are LED, some are whatever the older bulbs were that took ages to come up to full brightness when they aged. Is there any ingenious way to find the offending one, given they only get power at dusk and the sensor was put inaccessibly to other than a cat burglar at some dizzying height? Thanks.

author: sokoloff
author_rank: Super Contributor
timestamp: September 16, 2020, 09:16:06 pm
content: Day 1:I would unscrew/remove 4 of them.Day 2 if that does not trip:Restore 2 of them. Troubleshooting from here is probably obvious.Day 2 if that still trips:Remove 1 more.Day 3 if that still trips:Remove the last one.That should get you the fault (assuming a single fault) inside of 3 trials.The reason I'd start by killing 4 is you're not sure it's a bulb that's bad and 3 takes just as many days to check anyway.

author: bdunham7
author_rank: Super Contributor
timestamp: September 16, 2020, 09:24:49 pm
content: Are the bulbs accessible? If so, take them all out and try them in a lamp socket one at a time. FWIW, I personally have never seen an Edison-base bulb short or trip a breaker.

author: Brumby
author_rank: Unknown
timestamp: September 16, 2020, 11:05:47 pm
content: Keep in mind,anypart of the circuit could cause the tripping, not just the globes or holders. I presume the tripping is from overload ... you don't have these on an earth leakage/RCD breaker, do you?Quote from: bdunham7 on September 16, 2020, 09:24:49 pmMy experience also.
an ultralow noise preamp no output - Page 1
Forum section: electronics / beginners

author: ysccc
author_rank: Contributor
timestamp: September 29, 2025, 03:26:29 am
content: Hi, I'm using JFET and op amps to build an ultralow noise preamp. The simulation and calculation matches well. But I got some problem when testing it. I test 3 points in the circuit: VD1, VD2 and output. The signal from VD1 and VD2, the green one and yellow one in pic3 are basically the same to simulation. But the output of LT1028, the blue one is a direct line in oscilloscope, different from simulation. I don't know what's wrong with the circuit. Anyone can help me? :'( :'( :'(

author: TimFox
author_rank: Super Contributor
timestamp: September 29, 2025, 03:36:23 am
content: What’s the DC level of the flat-line output?The circuit looks normal: with the capacitor coupling, the output should have a reasonable DC offset and a few V AC output. Double check the wiring.

author: ysccc
author_rank: Contributor
timestamp: September 29, 2025, 03:40:39 am
content: The DC level of the flat-line is 15.58V, it's close to power supply 16.2V

author: TimFox
author_rank: Super Contributor
timestamp: September 29, 2025, 03:47:28 am
content: Probe the DC voltages directly at the power pins of the op amp: perhaps the negative power lead is open circuit.It's also possible the op amp is faulty.Or, perhaps the ground connection on R9 is open circuit, or otherwise miswired.

author: ysccc
author_rank: Contributor
timestamp: September 29, 2025, 03:53:33 am
content: Thanks for your reply! I will check it again.

author: ysccc
author_rank: Contributor
timestamp: September 29, 2025, 07:37:51 am
content: Thank you sir. The problem is that LT1028 is faulty. I change a new one. The wave appears! It confuse me a few days. Now I can report to my tutor. Thank you!
Analog Ammeter Protechtion - Page 1
Forum section: electronics / beginners

author: hpibmx
author_rank: Regular Contributor
timestamp: May 21, 2022, 03:25:21 am
content: I'm trying to make this diy power supply and I want to protect my analog ammeter from shorts!I will have digital and analog meter on it, so I will read my short from the digital ( I need to read shorts.)So I need to have reading on my shorts (on digital) at the same time protect my analog from damaging it, recently damaged 1 of it already.What I practiced putting a reversed diode but didn't really helped.any suggestion please?thank you

author: ledtester
author_rank: Super Contributor
timestamp: May 21, 2022, 03:52:11 am
content: Quote from: hpibmx on May 21, 2022, 03:25:21 amThe way you worded this makes me think you might have put the diode in the wrong way to protect the meter. The diode should not oppose normal current flow.To avoid having to worry about which way current is flowing through the meter just use two anti-parallel diodes across the meter as shown in this thread:https://www.eevblog.com/forum/projects/how-to-protect-analog-dc-ammeter/That thread also has other ideas such as fuses, PTC resistors, buffering op amp.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 21, 2022, 10:42:44 am
content: Without knowing the burden voltage of your ammeter I wouldn't know if the diode would work. The way to protect the ammeter with the diode is that the burden voltage must be less than the forward bias voltage of the diode. So normally the diode doesn't conduct either way. It will conduct in the forward bias direction when the voltage across the meter is higher than the forward bias voltage.
Analog amp meter over range - Page 1
Forum section: electronics / beginners

author: Tenkikun
author_rank: Newbie
timestamp: March 27, 2015, 01:11:40 am
content: Im working on my Electric bike for spring timeand i was thinking it would be fun to see how much power the speed control is pulling from the batteriesCan i put a cheap analog amp meter rated for 10A (4$) even tho the control has a upper limit of 15A?The amp meter im looking at is the picture attached.And the battery is a 36V pack of 3 SLA 12v batteriesThe only time the speed control would draw close to 15A is when taking off from a dead stop, and even then it alternate giving power and shutting off at about 4 times / second, not to strain the system too much.Would these short peaks of 15A hurt the Amp meter?I have tried searching this, but all info i get are about multimeters and such...

author: flynwill
author_rank: Regular Contributor
timestamp: March 27, 2015, 03:32:40 am
content: I can't say for sure, but the answer is "probably not". The ampmeter will "peg" but probably won't be harmed by a 50% overcurrent. It's shunt will probably at twice it's rated power dissipation, so it will get hot pretty quickly. But as long as its only a matter of a second or so it'll probably be ok. I have seen analog meters where the needle was run into the post with such force that the needle was bent, but I suspect that was considerably more that 50% over.

author: Seekonk
author_rank: Super Contributor
timestamp: March 27, 2015, 09:21:55 am
content: I'd say that is the one type of meter you can't destroy. They are also very inaccurate.

author: Tenkikun
author_rank: Newbie
timestamp: March 27, 2015, 11:37:42 am
content: Quote from: flynwill on March 27, 2015, 03:32:40 amOh wow... yeah i dont think i would do that much destruction xDQuote from: Seekonk on March 27, 2015, 09:21:55 amSounds like the type of amp meter i need, its just something for the fun of it.I will buy this amp meter and enjoy the build, thanks guys!

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: March 27, 2015, 03:38:41 pm
content: I would take the meter apart, find the shunt, and put a potentiometer voltage divider between the shunt and the coil. Then create a new scale using a scanner on the old one, then photoshop the scale to go to 15a. Print the new scale on paper, glue it to the old one, and then calibrate it to a known reference.

author: Seekonk
author_rank: Super Contributor
timestamp: March 27, 2015, 06:17:24 pm
content: All this meter has is a magnet on the movement and two leads come out from the current bar. The same meter is used for 100A, a wire clamp fits on the spade lugs that holds a #2 cable. No electrical connection, just the magnetic field from the wire drives the meter.
analog amplifier questions - Page 1
Forum section: electronics / beginners

author: 1uk3
author_rank: Contributor
timestamp: March 14, 2014, 07:16:45 pm
content: hii'm building a little device to measure LCR, phase shift, non-linearity,... + a simple signal generatortherefore i generate a signal (DDS <=1MHz, 16MHz sample rate), amplify it, and do a 4-wire voltage/current measurementi'm not very experienced in analogue circuit design, so i'm very thankful for tips.problem: for the signalgenerator i want to adjust the amplitude digitally, but i have no idea how to do that!i doesn't have to be very accurate and i only need 10-20stepsmaybe a digital potentiometer instead of R9?i try to use cheap parts, so please don't recommend very expensive chips!her is what i have so far(from left to right):signal from DDS chip(0-620mV) --> filter --> AB-amplifier -->DUT --> shunts --> voltage/current amplifier --> ADCsSEE ATTACHMENT!i didn't put much thought into shunt and op-amp resistor values jet. i first want to know the output voltage rangecan you give me some hints please?many thankslukasand sorry for my bad english
Analog board start-up - How do you handle digital stuff? - Page 1
Forum section: electronics / beginners

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: June 29, 2018, 11:39:10 am
content: So I think this is going to be something that every person doing analog design goes through a lot - You get your devboard in with the PLL/DAC/VCO/... on it in, and you want to do the hello-world equivalent with it.How do you approach this? Currently, my go-to is just hook it up to an Arduino, but that ends up with a lot of convoluted coding. I was wondering if there is any system that is like the "opposite" of a logic analyzer, where I can visually draw the waveform I want to output on the parallel bus to set up the control registers and then hook up a board to execute them?

author: rstofer
author_rank: Super Contributor
timestamp: June 29, 2018, 01:51:05 pm
content: If I understand this, you want to output a parallel bus of signals and you want a convenient way to describe the various transitions versus time.I haven't done it but the Digilent Analog Discovery 2 will do this. You can download the free software and see what you can make of it. You would have 16 signals to do with as you will. Input, output, bus, whatever.https://reference.digilentinc.com/learn/instrumentation/tutorials/ad2-pattern-generator/startThis isn't like 'drawing' a signal but it's close.

author: tggzzz
author_rank: Super Contributor
timestamp: June 29, 2018, 01:56:24 pm
content: Presuming you are talking about digital signals, I just code it directly in xC for the XMOS processors. Hence for a standard two-rows of alphanumeric characters with RW, E, and DATA lines, the code is:Code:static void lcdWriteByteNoWait(int byte) {uint32_t tStart;lcdRW <: 0 @ tStart; // set the RW line low, and record the time// high nybblelcdE @ (tStart+Tsp1) <: 1 ; // wait until Tsp1 later, then set the E line activelcdData @ (tStart+Tsp1+Tpw-Tsp2) <: (byte >> 4); // wait until it is "safe" to change the data lines, and then change themlcdE @ (tStart+Tsp1+Tpw) <: 0;// low nybblelcdE @ (tStart+Tsp1+Tcyc) <: 1 ;lcdData @ (tStart+Tsp1+Tcyc+Tpw-Tsp2) <: (byte & 0xf);lcdE @ (tStart+Tsp1+Tcyc+Tpw) <: 0;// complete the two cycles; use RW to avoid optimisation// and to give an external hint it has finishedlcdRW @ (tStart+Tsp1+Tcyc+Tcyc) <: 1;}where the magic time constants are read directly from the data sheetCode:// interface timing in 100MHz ticks#define Tsp1 (6) // min 40ns#define Tsp2 (10) // min 80ns#define Thd2 (2) // min 10ns#define Tpw (26) // min 230ns#define Td (14) // min 120ns#define Tcyc (60) // min 500nsA good feature of the XMOS processors is that they can also be doing other time-critical I/O and processing simultaneously. In my frequency counter application, that means comms over a USB link, plus counting transitions in a 62.5 MHz input streams.
Analog course notes for the intermediate  - Page 1
Forum section: electronics / beginners

author: Jebnor
author_rank: Regular Contributor
timestamp: October 03, 2013, 05:09:10 pm
content: I was looking around for info on Various Analog electronic circuits and ran across old course notes(1999) from a professor at the University of Oregon, Raymond E. Frey.The notes start with an overview of Ohms and Kirkoffs Laws, Progresses through Transistor biasing, Differential amplifiers, OpAmps and Basic RF.The full course notes are available in one PDF here:http://zebu.uoregon.edu/~rayfrey/431/AnalogNotes.pdfAnd individual sections, in PDF, are listed here:http://zebu.uoregon.edu/~rayfrey/431/I'm reading through them now. I thought you all might be interested.

author: sanjin
author_rank: Newbie
timestamp: October 08, 2013, 09:14:14 am
content: Hi JebnorThanks for shearing.Sanjin

author: magnus0re
author_rank: Contributor
timestamp: October 08, 2013, 09:49:19 am
content: It is nice, too bad it only goes through basic design equations. I need more, so I would recommend the book"Design with Operational Amplifiers and Analog Integrated Circuits" by Sergio Franco.Also If you really want to grind your bones, there is "Design of High-Performance Negative-Feedback Amplifiers" by E. Nordholt. Its on my syllabus this semester.
Analog Design Basics - Page 1
Forum section: electronics / beginners

author: EEVaditya
author_rank: Regular Contributor
timestamp: April 19, 2016, 11:41:41 am
content: Hello,I am looking for Technical stuff (Books,Documents) regarding Analog Design which has got information from Novice stage to Expert stage.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: April 19, 2016, 11:47:50 am
content: https://www.eevblog.com/forum/beginners/little-reference-book-produced-by-texas-instruments/

author: MrSlack
author_rank: Frequent Contributor
timestamp: April 19, 2016, 12:07:07 pm
content: http://www.amazon.com/dp/0521177235/

author: Alex Trofimov
author_rank: Contributor
timestamp: April 19, 2016, 02:00:20 pm
content: Agilent Network Analyzer Basics — it's about network analyzers, as it says, but it contains a lot of advanced electronics basics, explained in very simple and clear way. (http://cp.literature.agilent.com/litweb/pdf/5965-7917E.pdf)Look for Analog Dialogue:http://www.analog.com/library/analogdialogue/index.htmlLinear Circuit Design Handbook, edited by Hank Zumbahlen:http://www.analog.com/library/analogDialogue/archives/43-09/linear_circuit_design_handbook.htmlLT's AN47 - High Speed Amplifier Techniques by Jim Williams:www.linear.com/docs/4138There's a lot more app notes by AD, TI, LT and MAXIM. These are just the most conprehensive and remarkable to me, that popped out in the head.And there's a lot of great small app notes about all sorts of stuff. Higly recommend to check them out. :-)

author: yashrk
author_rank: Frequent Contributor
timestamp: April 19, 2016, 06:35:02 pm
content: Linear Technology has really great video series on op-amp (which I really find helpful) and many other of their product like sensors and regulators. They also have good handbook on analog design.You may also like to learn circuit simulation, LTspice is the best.Happy Making!!
Analog Devices AD8011 (300 MHz Op Amp) - Page 1
Forum section: electronics / beginners

author: wobbly
author_rank: Regular Contributor
timestamp: October 19, 2024, 11:04:25 am
content: Spent some time rummaging in my parts bin and found a pair of DIP-package AD8011 op amps in the original antistatic tube.https://www.analog.com/media/en/technical-documentation/data-sheets/AD8011.pdfThese have never been used and were manufactured in the 26th week of 1998. I'm pretty sure they'll be from the same batch out of the factory.Farnell still sells these bad boys for£8.28each!These seem to be some pretty nice op amps in a hobbyist-friendly package, so now I'm keen to use them in a project. But I'm not sure what.My first thought was perhaps something like a buffer for my GPSDO so I can distribute the signal to multiple instruments. Not sure.So I'd like to get some ideas from you guys - if you had two of these AD8011s, what would you use them for?

author: Kleinstein
author_rank: Super Contributor
timestamp: October 19, 2024, 06:57:30 pm
content: The DIP case is not that beginner friendly for such a fast OP-amp. It would be for a slow amplifier, but with high speed the size of the case is more of a downside. There is a good reason why most really fast parts are only available as SMD.It is near impossible to use this part on a bread board.The amplifier is not that special, that it is really worth searching for a reasonable use for it, just because it may have been and still is expensive.

author: CaptDon
author_rank: Super Contributor
timestamp: October 20, 2024, 02:01:23 am
content: The nice thing about all of that bandwidth is that with special care about lead length and power pin bypassing it can truly pass 10MHz square waves without rounding the corners!! Probably would make a good comparator up to a few MHz.

author: jwet
author_rank: Frequent Contributor
timestamp: October 26, 2024, 05:25:09 pm
content: Note that this is a current feedback amplifier (CFA). The data sheet is very complete and it would be a fun part to play with if you're not familiar with these. With a std. voltage feedback amp, you could use lots of gain and still have good bandwidth, like Capt Don noted, but CFA's don't do very will in circuits with much gain (>10). These parts are best suited for high end analog video processing with low diff gain and phase. These parts were designed for these kind of apps. Other uses are medium frequency signal processing similar to video in terminated systems. They would make a decent output amp for a GPSDO for a very nice 10 MHz sine wave for example. Have fun.
Analog Discovery 2 Sale - Sort Of - Page 1
Forum section: electronics / beginners

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 15, 2021, 07:36:16 pm
content: I just got an email newsletter from Digilent, the makers of the AD2. They announce that they will give a 50% discount on the purchase of an AD2 IF you buy one of their FPGA Dev boards that cost over $100. That is potentially a $200 discount but you have to spend at least $100 to get it. OK if you were in the market for one of their FPGA boards anyway. Disclaimer, look for any fine print, I have not personally checked this off out past a quick read of the newsletter they send me.

author: bingo600
author_rank: Super Contributor
timestamp: September 15, 2021, 08:17:00 pm
content: Seems valid enough ... Havent bought but added to basket
Analog division of two inputs + result indication: viable? - Page 1
Forum section: electronics / beginners

author: shapirus
author_rank: Super Contributor
timestamp: February 05, 2023, 04:16:44 pm
content: I am developing a simple electronic constant resistance load (pure analog so far) for which I would like to add a display showing current value of resistance calculated from actual measurements.To get it, I can divide two inputs: 1) input voltage - by - 2) voltage drop on the current sense resistor, representing current.Question 1: is there a reasonably simple pure analog circuit that will divide two input values and provide result as a voltage output?Question 2: same thing for indication, are there any ICs that will take a voltage input and handle all the decoding and output the value on a, for example, 7-segment LED or LCD display? I need 3 digits with a decimal point.From what I could find so far, it doesn't sound reasonable to try and implement this using analog components, and it'll likely be much easier to use a small microcontroller that will get the input voltages via ADC, do the calculation in software and output the result on pretty much any kind of display.But, maybe I am missing something and there are ways to implement this in a simple analog circuit? Are there any ICs designed for a similar job?

author: ledtester
author_rank: Super Contributor
timestamp: February 05, 2023, 04:26:06 pm
content: There are analog multiplier/dividers chips, e.g.:https://www.analog.com/en/product-category/analog-multipliers-dividers.htmlThere are also A/D converters which can drive LED/LCD displays directly. The ICL7107, for instance, is a venerable device:https://www.analog.com/en/products/icl7107.htmland other display-oriented A/D converters can be found here:https://www.analog.com/en/product-category/displayoriented-adcs.html
Analog electronics book recommendations? - Page 1
Forum section: electronics / beginners

author: jay
author_rank: Regular Contributor
timestamp: February 25, 2015, 01:04:15 pm
content: There are many great electronics resources online but the quality varies and it's all so fragmented.. and I like books. I'm looking for a book about analog electronics, but many books aimed for EE students seem to heavily emphasize the theoretical side. Any suggestions for a book starting from slightly above the beginner level and covering broadly the analog design from a practical perspective (with reasonable amount of theory and analysis, but not just that)? "The art of electronics" was great for getting started but it's outdated and it tried to cover everything.. now I'm just looking for the good (analog) stuff with more depth. What is the bible of analog electronics?

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: February 25, 2015, 01:24:37 pm
content: The third edition of "The art of Electronics" will be here soon.Whatever it is, it should be a must !http://www.amazon.com/Art-Electronics-Paul-Horowitz/dp/0521809266/ref=sr_1_1?ie=UTF8&qid=1424870605&sr=8-1&keywords=art+of+electronics

author: tggzzz
author_rank: Super Contributor
timestamp: February 25, 2015, 02:15:47 pm
content: My list is here, particularly sections 1 and 3https://entertaininghacks.wordpress.com/library-2/bookshelf/

author: lilmantis
author_rank: Contributor
timestamp: February 25, 2015, 03:44:09 pm
content: I found these to be usefull:http://www.analog.com/library/analogDialogue/technical_books.html

author: German_EE
author_rank: Super Contributor
timestamp: February 25, 2015, 09:21:56 pm
content: Bob Pease 'Troubleshooting Analog Circuits'The ARRL Handbook

author: nanofrog
author_rank: Super Contributor
timestamp: February 25, 2015, 09:39:38 pm
content: Might want to givePractical Electronics for Inventorsa look as well (paperback, so it's inexpensive). FWIW, I've seen the 1st and 2nd editions online as .pdf files that should give you a really good idea if you don't want to just rely on the preview offered on Amazon.Charles Platt'sEncyclopedia of Electronic Componentsbooks if you're interested in components; uses, pitfalls,... (Vol. 1 & 2) might also be useful.

author: KJDS
author_rank: Super Contributor
timestamp: February 25, 2015, 09:48:34 pm
content: This one.http://www.amazon.co.uk/Science-Analog-Circuit-Design-Engineers/dp/0750670622There's a couple of others in the same series.

author: jay
author_rank: Regular Contributor
timestamp: February 27, 2015, 09:18:13 am
content: Quote from: KJDS on February 25, 2015, 09:48:34 pmNot exactly what I was looking for, but it looks really interesting!Thanks!

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: February 27, 2015, 10:38:32 am
content: Experimental Methods for RF Design or its predecessor Solid State Design for the Radio Amateur
Analog Front End Design Strategy - Page 1
Forum section: electronics / beginners

author: johnsmittysmitty
author_rank: Newbie
timestamp: October 01, 2015, 11:29:44 am
content: Hello EEVblog forum,So I am able to analyze filters for cutoff, frequency response etc. But where I get lost is practical analog filter application for the best results.Lets say I have a signal at 1khz that I want to filter out and sample why can't I put a bandpass with pass band at 900Hz and 1100Hz. Whenever I do this my signal seems to become too distorted.Also, what order to do gain/filtering.Any practical advice to filter placement will help.Thank youJohn

author: Dave
author_rank: Super Contributor
timestamp: October 01, 2015, 09:00:34 pm
content: You can do that and you should be able to get good results. How about you post some scope screenshots and explain what you were expecting to achieve.

author: rjeberhardt
author_rank: Regular Contributor
timestamp: October 02, 2015, 09:29:38 am
content: Quote from: johnsmittysmitty on October 01, 2015, 11:29:44 amIs your signal a pure sine wave? Any other waveform will be distorted by that filter.Russell.
Analog Ground on a buffered R2R ladder DAC - Page 1
Forum section: electronics / beginners

author: davemisbehave
author_rank: Unknown
timestamp: December 30, 2014, 12:21:14 am
content: Hi!I've built a simple R2R DAC using resistors, a rail-to-rail opamp and some logic. So far it's been working well on a single supply, but I want to improve upon the design by adding dedicated positive and negative power rails for the analog part of the circuit. I'm re-spinning the board and this time I also want to incorporate separate analog and digital grounds, as well as the analog split supply. I've added a simplified schematic that might help the following two questions I have:1. Should the first resistor of the R2R ladder (R9 in my picture) be connected to digital ground or analog ground?2. Should I connect the analog and digital grounds, and if yes, where? At the power supply (DP831A), or should the GND plane and AGND plane be connected somewhere?Please see the attachment I included for a full understanding of the context.Cheers,Dave MisbehaveEDIT: R13 should be 10k (copy/paste error)! Thanks for pointing it out, nitro2k01!

author: Christopher
author_rank: Frequent Contributor
timestamp: December 30, 2014, 07:31:55 am
content: Resistors to digital ground, I think.Two ground planes, joined at one spot with a 0r resistor.Don't forget your decoupling.I'd put a series current limit resistor on the opamp output after the feedback

author: nitro2k01
author_rank: Frequent Contributor
timestamp: December 30, 2014, 07:46:42 am
content: Maybe it's just an error in the schematic that is not reflected when you're building the circuit, but look at R13!

author: tggzzz
author_rank: Super Contributor
timestamp: December 30, 2014, 10:01:13 am
content: Quote from: Christopher on December 30, 2014, 07:31:55 amUsually a mistake; see books/articles and manufactuers' literature on low power mixed signal PCBs, e.g. for ADCs and DACs.Much better to consider where the "return" currents flow, and to keep them separate, and to minimise the loop area for each individual contribution (analogue/digital, signal/power) to the total currents flowing.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 30, 2014, 01:04:29 pm
content: The grounds are one in the same. Digital VCC should be filtered, or use analog. Why? Because it's NOT a digital supply -- you are using the gate output pins as one-bit DACs! These are, in turn, weighted by the R2R divider.Also, the output resistance of each pin is a factor in the weight of each, and variation in that resistance limits how stable a conversion you can produce here (over manufacturing and temperature variation).Tim

author: davemisbehave
author_rank: Unknown
timestamp: December 30, 2014, 06:21:13 pm
content: Thanks for the replies. So, my guesstimate would be to connect R9 to AGND and to connect AGND and GND at the power supply (not the planes). Is this correct, and if not why?P.S.: R13 should be 10k (thx, nitro)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 31, 2014, 12:23:32 am
content: Yes. So it's the same ground plane everywhere.Tim