hybridfree/eevblog-posts huggingface dataset:
Decoding Differential 2 wire RS-485 on Agilent MSOX Digital Channels - Page 1
Forum section: electronics / beginners

author: K1JOS
author_rank: Regular Contributor
timestamp: August 08, 2014, 08:29:59 pm
content: I have been able to use a differential probe (1141A) (single channel) to decode the RX side of a RS-485 stream but to see the TX on the Agilent 3054A I have to reselect in the Serial menu the RX/TX probe channel.Is there any way I can decode both RX and TX for RS-485 half duplex 2 wire simultaneously? Can this be done using the Digital channels and if so how do I set up to get the differential signal? The user manual doesnt dicuss thisthanksJerry

author: ConKbot
author_rank: Super Contributor
timestamp: August 09, 2014, 03:20:28 pm
content: If you have a differential probe for the RX side, can you use 2 probes on the tx side + subtract on the math menu to get your TX signal and tell the decoder to use the math function?Or alternatively, if your not worring about signal shape/eye diagram (it appears you arent) get a few RS485 recievers from TI or maxim to do your differential business and pipe the output of those into the scopes.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 09, 2014, 03:36:03 pm
content: Unless it's a noisy/distorted signal just look at TX+ and ignore TX-Decoding TX and RX on the same bus is tricky, but can be sone with some resistors to fudge the levels to be different for each sender.However by far the easiest, where possible is to tap into the equipment before the RS485 transceiver
Decoding unkown Serial data wireless alarm  - Page 1
Forum section: electronics / beginners

author: Ginettag20
author_rank: Regular Contributor
timestamp: June 30, 2017, 07:00:29 pm
content: Hello allI recently indulged in my favorite extreme sport of skip diving (dumpster if outside UK) and surfaced with an alarm system and Just for fun I am doing a bit of a tear down.The alarm system is relatively new 2009 vintage made by RISC and is a wisdom model. Its has various features such as phone dialing and voice record and playback features. Its is also designed to connector to various sensors and remote controls using RF.The RF transceiver is operating in the European license free band 870MHz and i think is using OOK/ASK encoding. I can see that it is transmitting every few seconds and I have used a SDR and spectrum analyses to have a look. I was hoping to try and do some decoding via the SDR but to be honest this is beyond my competence for the moment.I have instead hooked the scope up to the PIC processor output that is driving the transceiver TX and have captured the serial data. The PIC is 18F452 and its using pin 10 as the output. Pin 10 is listed as RB2/INT1 but importantly its not connected to the PIC EUART which is on pin 44 and I think may be implementing SPI to some other on board peripheral. I am guessing the designer of the alarm could therefore be bit banging RB2 for transmitting. Perhaps even rolled their own protocol.It looks like the unit transmits a relatively long stream of 0 and 1 then takes a break for quarter of a second then sends what looks like data multiple 1s and 0s etc. I am guessing the long preamble could be to give the peripherals time to wake up or perhaps is for clock syncing.It looks to me like the bit length is 200uS and I think this gives my a baud of 5000. I have serial decoding on my scope but how to identify the start and stop bits and packet size and parity etc. I also have a USB style logic analyser that has serial decoding but again if I dont know what the serial parameter are ?Just after some general advise on what to do next if anything can be done to try and decode the serial data. I note there a nice in circuit programming header next to the PIC but they must have enabled CP.Thanks for any comments and helps - Regards Chris

author: floobydust
author_rank: Super Contributor
timestamp: June 30, 2017, 07:27:40 pm
content: This kind of reverse-engineering I've seen with low cost weather station transmitters. Usually ISM band 433MHz ASK/FSK/OOK.Hackaday reverse-engineering-wireless-weather-stationsTX29 Protocolreverse-engineer-wireless-temperature-humidity-rain-sensorsHackaday reverse-engineering-a-wireless-protocolI believe the long preamble is for the receiver AGC.

author: Ginettag20
author_rank: Regular Contributor
timestamp: June 30, 2017, 07:35:42 pm
content: Thanks FloobyThat's a good link and I'm getting a very similar preamble. Also just noted that I don't appear to have more than 2 bit times for 1s or 0s so perhaps that could also imply Manchester encoding.
Decoupler for my function generator?! - Page 1
Forum section: electronics / beginners

author: chrisstra84
author_rank: Contributor
timestamp: March 07, 2015, 07:55:03 pm
content: Hello guys!I have made a measurement with my amplifier. You can see it in the picture below. On the left it’s ok! But on the right it’s a “problem”. I have figured it out by accident.Fortunately, nothing is happened because there is a protection in the amp!So my question is how can I protect my devices? What can I do to make my function generator floating? So I want to decouple the generator. What is a good decoupler or ground loop isolator for the output? It is generally possible?Christian

author: Zero999
author_rank: Super Contributor
timestamp: March 07, 2015, 08:25:42 pm
content: If it's just audio, you could use an audio isolation transformer.

author: max666
author_rank: Frequent Contributor
timestamp: March 07, 2015, 08:34:06 pm
content: And isolation transformer, which we discussed in your other threadSafety first with oscilloscope & Co., would prevent that problem.And you told us you've watched “How NOT to blow up your Oscilloscope”!!! Or did someone not pay attention to what Dave was saying?!

author: chrisstra84
author_rank: Contributor
timestamp: March 07, 2015, 08:56:24 pm
content: Yeahh,I have seen it. But the generator was out of my mind. So the amp itself has no mains earth connection. And so the DUT was not mains earth referenced. But I have made a new one over the generator and so I have closed the circuit.So, what kind of audio isolation transformer can I use? Or is there any kind of decoupler integrated in a BNC adapter?So you can learn, read, watch and listen to any kind of electronic stuff, but you will never forger a mistake made by yourself.I hope so.Christian

author: chrisstra84
author_rank: Contributor
timestamp: March 07, 2015, 10:06:32 pm
content: Is this a possible way?http://www.amazon.com/Gino-Female-Coaxial-Ground-Isolator/dp/B0038O9R86I search this kind of ground loop isolator with input/output resistance of 50 ohm. Or can I make one by myself? What I need for this?Christian

author: VictoriaGuy
author_rank: Contributor
timestamp: March 07, 2015, 11:15:15 pm
content: I'd use something like this:http://www.hammondmfg.com/560.htmfor audio isolation.It helps that I have some on my parts shelf!
Decoupling cap and potentiometer - Page 1
Forum section: electronics / beginners

author: Lucky-Luka
author_rank: Unknown
timestamp: March 31, 2021, 08:41:14 am
content: Hi allI've found a schematic in an Arduino book and this is my question: is a decoupling cap needed for a potentiometer to be read correctly by a uC?Thanks

author: Ian.M
author_rank: Super Contributor
timestamp: March 31, 2021, 09:20:31 am
content: An Arduino is *NOT* a simple MCU, its a MCU board with on-board decoupling. Unless a MCU is very close to a low impedance supply source, local decoupling is usually required for a MCU to function correctly and reliably.Now lets consider the schematic you posted. RC servos draw large current spikes, especially if a large position change is commanded, so a large decoupling capacitor as close as possible to the servo is essential if they share the same supply as any MCUs or other logic. However the other 100uF decoupling capacitor would be best *NOT* wired across the potentiometer but directly across the Arduino's +5V and Gnd pins. where it could be most effective at minimizing the disturbance from the servo current spikes.Ideally the potentiometer would be wired up with shielded cable, with the shield grounded at one end (usually the Arduino end) and soldered to the pot body if its metal. If EMI resistance is less important, an unscreened cable consisting of three wires twisted together may be used, or even three adjacent wires in a ribbon cable. Avoid individual wires with a large loop area. Its frequently helpful to add a 100nF capacitor to ground directly at the ADC pin to low-pass filter the voltage from the potentiometer.
Decoupling Capacitor in DC/DC Converter - Page 1
Forum section: electronics / beginners

author: Nikos A.
author_rank: Regular Contributor
timestamp: June 23, 2019, 12:36:52 pm
content: Hi everyone,I am going to use this DC/DC converter to supply an Oven Controlled Crystal Oscillator (OCCL) and I've got several question regarding the decoupling capacitorshttps://eu.mouser.com/datasheet/2/687/tel5-519367.pdfhttps://abracon.com/Precisiontiming/AOCJY3.pdfhttps://eu.mouser.com/ProductDetail/ABRACON/AOCJY3B-10000MHZ-E-SW?qs=%2Fha2pyFaduheXwhiO7qFNqRHAJBxDf6eSy3uqFqG%252BNw%3DOCCL output is selected to be 10Mhz sinewave.I want to calculate the decoupling capacitors after the DC/DC converter and I need your advice.What I know so far is that in order to calculate a proper decoupling network you need to calculate a target impedance and then select the proper capacitors in order to maintain a low impedance path below the target impedance for the whole frequency range that transient current exist.The formula for the target impedance is Ztarget = (Rail Voltage x max. Voltage Ripple) / Transient currentFrom OCCL datasheet,Rail Voltage = 12V (actually there are three available Vcc options 3.3V, 5V and 12V but at my application I will use 12V)max. Voltage Ripple = 5%Transient current while turn ON state (3.6W power consumption) @ 12V = 300mA(this is the maximun transient current isn't it?)Taking into consideration the information above the target impedance should be Ztarget = (12 x 0.05) / 0.3 = 2 OhmsSo I need a decoupling network with impedance path under 2 Ohms,is this correct?Using SimSurfing tool provided by Murata and selecting two capacitors 0.1uF and 0.01uF it seems like is maintained an impedance path under 2 Ohms for the frequency range 1Mhz - 1GhzSome questions come to the surface...1.How do I calculate the appropriate frequency range to maintain low impedance path?I found a formula that estimates the bandwidth, BW = 0.35/RT, where:BW: BandwidthRT: Rise TimeCan I apply this formula in my case?What is the minimum frequency?2.The intersection of capacitive (green line) and inductive (blue line) region of the capacitors is going to create an impedance peak (anti-resonance effect).. I don't know the magnitude of this peak and also don't know whether is going to affect the performance.From your experience how to you manipulate this effect?3.Converter's datasheet refered Ripple & Noise and Switching FrequencyShould I take into consideration these parameters? Should I include a decoupling capacitor BEFORE the converter due to its switching frequency?Thanks in advance

author: Nikos A.
author_rank: Regular Contributor
timestamp: June 25, 2019, 09:29:11 am
content: Anyone?
Decoupling capacitor voltage   - Page 1
Forum section: electronics / beginners

author: Aztlanpz
author_rank: Regular Contributor
timestamp: January 30, 2018, 12:19:45 am
content: I am adding decoupling capacitor to a microcontroller that are rate at 10 V is that an accountable margin when the microcontroller is running at 5 V?

author: drussell
author_rank: Super Contributor
timestamp: January 30, 2018, 12:31:11 am
content: Quote from: Aztlanpz on January 30, 2018, 12:19:45 amUhhh...Yes, a decoupling capacitor rated for 10 volt maximum, continuous operation would have sufficient margin (voltage headroom?) for a microcontroller that is operating on a 5 volt supply in virtually every scenario.Using a 6.3 volt on a 5 volt rail is about theabsolute minimumlimit but going to 10, 12, 16 volt in most design scenarios is a valid choice... probably a wise one...

author: mariush
author_rank: Super Contributor
timestamp: January 30, 2018, 12:46:15 am
content: Decoupling capacitors are usually ceramic ones, in the 0.01 uF to 0.1uF ... With ceramic capacitors it's sometimes important to be aware of voltage bias , see :https://www.maximintegrated.com/en/app-notes/index.mvp/id/5527Probably wouldn't matter for a microcontroller, but for other devices, maybe you'd want to use 25v or higher rated ceramic capacitors.If you mean some bulk electrolytic capacitors like let's say 100-470uF or something like that, then yeah, 6.3v should be the minimum. Note though that often 10v rated capacitors of such low values may have the same diameter and sometimes can be cheaper than 6.3v rated capacitors.And for lower capacitances like 100uF or lower, voltage ratings like 25v and 35v are common, because you get around the same diameter and height regardless of voltage so makes no sense restricting yourself to 6.3v or 10v rating.
decoupling capacitor - Page 1
Forum section: electronics / beginners

author: csabia30
author_rank: Newbie
timestamp: March 23, 2016, 11:58:02 pm
content: when i read about decoupling capacitors talks about a bypass capacitor preventing the effect of one circuit to another but I really don't understand how it is being connected. please can I get help from anyone who knows

author: mariush
author_rank: Super Contributor
timestamp: March 24, 2016, 12:06:21 am
content: Start here:

author: hamguy
author_rank: Newbie
timestamp: March 24, 2016, 04:07:53 am
content: Quote from: csabia30 on March 23, 2016, 11:58:02 pmReally not complicated. Decoupling capacitors are usually connected from the power supply pin (or terminal) of a circuit or an IC to ground or power supply common. Capacitors pass AC and block DC so any signal or other voltage variations on the power supply rails will be, in effect, shunted to ground leaving the DC supply rails still at their DC voltage with no signal riding on them. Years ago, they were called "filter capacitors", somewhat of a misnomer. The positive line to be decoupled is connected to the + side of the C, the - side of the C is connected to power supply common. A negative supply line would have the - of the C connected to the supply line and the + side of the C connected to power supply common.By removing any signal from the supply lines, circuits with poor common mode rejection will be unaffected by any effect of other circuits on the supply lines. Thus, each individual stage or circuit sharing supply lines with other stages or circuits is "de-coupled" from them.Coupling capacitors, on the other hand, connect the signals from the output of one stage to the input of the next. Since Cs block DC and pass AC, the signal gets coupled from the output of one stage to the input of the next without affecting the DC voltages in either circuit.-g

author: Alex Trofimov
author_rank: Contributor
timestamp: March 24, 2016, 10:46:06 am
content: Don't know if it suitable, but maybe you'll find it useful for you.Here's a really comprehensive guide in decoupling (and noise supression, they're related) by Murata:http://www.murata.com/~/media/webrenewal/support/library/catalog/products/emc/emifil/c39e.ashx
Decoupling Capacitors - when to use them? - Page 1
Forum section: electronics / beginners

author: higginsdj
author_rank: Contributor
timestamp: February 24, 2023, 03:19:38 am
content: So I was given this link to find out more about building and using transistor and diode logic circuits. My question is regarding the use of de coupling capacitors.https://www.nutsvolts.com/magazine/article/transistor_clockA resistor and capacitor have been used between all the different logic units in this circuit but I don't know why. In all my experimentation, doing this coverts the outgoing DC signal into an AC signal and so inserts an AC signal into the next logic unit. Why not simply connect each logic unit together without the capacitor so you get DC signal in and DC signal out? In my experiments the 2 diode AND gate with following resistor and capacitor turned a 0-5v Square wave output signal (I used a 5v VCC) into a +/-4.1v Cap charge, discharge signal.Now I do understand why they are used in audio and amplifier circuits - just not in this case.What am I missing?

author: BillyO
author_rank: Super Contributor
timestamp: February 24, 2023, 04:00:01 am
content: As it stands your question is rendered meaningless by fortune of the picture you post.Can you supply a schematic, or better still, a DETAILED (as in in-focus and appropriately scaled) picture of your test circuit in which we can see every detail?It really looks like you put the capacitor in series with the device rather than in parallel.

author: ataradov
author_rank: Super Contributor
timestamp: February 24, 2023, 04:07:01 am
content: Those are not decoupling capacitors. They are there precisely to do what you see on the scope - convert square wave into short pulses. This circuit specifically toggles on the negative edge of the square wave.Normally the toggle voltage is kept at 1/2 VCC by the resistive divider. When the negative edge happens, it shortly pulls the cathodes of the diodes low, those toggling the flip flop.But yes, it is better to specify what capacitors you are talking about. Because the ones shown at that link are only necessary before the flip flops. Logic gates should have stable levels, which is shown on the FIGURE 6.

author: higginsdj
author_rank: Contributor
timestamp: February 24, 2023, 08:24:23 am
content: Quote from: BillyO on February 24, 2023, 04:00:01 amThe schematic is in the link. I looked them up again in my textbook and have mistaken AC Coupling with Decoupling - so much to learn.Cheers

author: higginsdj
author_rank: Contributor
timestamp: February 24, 2023, 08:29:27 am
content: Quote from: ataradov on February 24, 2023, 04:07:01 amOK, thanks. More to learn and experiment with.
Decoupling Capacitors - Page 1
Forum section: electronics / beginners

author: JDemo
author_rank: Contributor
timestamp: September 05, 2018, 06:09:36 pm
content: Below I've attached an image of a basic power supply schematic (Img C) I found on the internet. It pretty much gives a good general idea to my question. My question is for the traces from the regulator, would the output trace (VCC33 in this case) come directly from the regulator (Img A) or would it have to branch off of the trace going into the 2nd decoupling capacitor (Img B) or another option which I'm unsure of?

author: wraper
author_rank: Unknown
timestamp: September 05, 2018, 06:22:41 pm
content: Layout on the picture is bad but the worst part is that AMS1117 shouldn't be used with ceramic cap on the output due to too low ESR and it may oscillate. It should be used with electrolytic or tantalum cap or ceramic cap with added series resistor. You should take output through the output cap, branching defeats the purpose of the cap.

author: JDemo
author_rank: Contributor
timestamp: September 05, 2018, 06:25:50 pm
content: Quote from: wraper on September 05, 2018, 06:22:41 pmThanks for the info on the caps. Basically light the image I've attached now (But with electrolytic or tantalum caps)? *Ignore the shitty traces, just for example*

author: wraper
author_rank: Unknown
timestamp: September 05, 2018, 06:53:56 pm
content: Yes, like this. Though place capacitors close to the IC terminals. Probably best to rotate them by 90 degrees.

author: JDemo
author_rank: Contributor
timestamp: September 05, 2018, 07:31:04 pm
content: So is this ok? Also on an unrelated/semi-related note, would this work as a valid 5v -> 3.3v power source?Also ignore all the random planes and vias Im just testing some things which was for an unrelated problem where I couldnt for some reason output CAM files when using a ground plane. Turns out for some god awful reason my projects switch units from mils to inches and I type in the measurement for mils into a project using inches and it breaks things

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 05, 2018, 10:38:17 pm
content: I'm going to be bold and say,It doesn't matter.Tim
Decoupling caps different between data sheet and evaluation kit. - Page 1
Forum section: electronics / beginners

author: tehtehteh
author_rank: Regular Contributor
timestamp: June 17, 2021, 04:41:33 pm
content: Using a MAX7044 transmitter the data sheet typical application circuit has a single decoupling capacitor and this statement: "Supply Voltage. Bypass to GND with a 100nF capacitor as close as possible to the pin."https://datasheets.maximintegrated.com/en/ds/MAX7044.pdfYet the evaluation kit has 2 caps, 220pF and 0.01uF.https://datasheets.maximintegrated.com/en/ds/MAX7044EVKIT.pdfI am searching for as much space as possible on the PCB and I wonder what your thoughts are on just using the 100nF capacitor. It's in the data sheet so it should be fine right?

author: Siwastaja
author_rank: Super Contributor
timestamp: June 17, 2021, 05:02:04 pm
content: Being a high-frequency device, low impedance at high frequencies may be important. Maybe the devkit designer plays with the old classic myth of paralleling different capacitor values for lower impedance across the frequency spectrum. In reality, all that matters is the ESL. Paralleling multiple has advantage if they can get the 220pF in a smaller case and place it closer to the pin, providing a "quicker cache" for the energy. This was important back when MLCCs were not available in high capacitances and small packages.In reality, simply for physical manufacturing reasons, you are likely limited to using 0402 or just maybe 0201 parts and have some courtyard placement limit like 0.2mm; and you can definitely get a 100nF cap in 0402 and even 0201 just fine, so it will provide same or lower impedance over the whole spectrum compared to strange mixes of parallel caps. Also, parallel mixes have a risk of resonating with each other.
deferential input - Page 1
Forum section: electronics / beginners

author: baksuz
author_rank: Newbie
timestamp: April 10, 2019, 02:02:59 pm
content: Hello,Is there on market any chips that measure deferential input, and they shift it to 0-5V ?

author: rstofer
author_rank: Super Contributor
timestamp: April 10, 2019, 03:53:25 pm
content: In effect, op amps are differential amplifiers. The output voltage is some gain factor times the difference in voltages at the inputs. See section 6.5 of the book linked below.We need a lot more information! What is the nature of the inputs? There are true differential amplifiers (instrumentation amplifiers) but they are internally built by more than one conventional op amp. You can also take differential measurements with a common op amp. But, at a minimum, we need to know the voltage range of the signals. Google for 'instrumentation amplifier'.As to output voltage range, sure, it can be anything within the rails of the op amp power supplies or as limited by the datasheet to a couple of volts away from the rails. In other words, if you want to swing to exactly 5V and 0V, you probably can't get away with a 5V single supply op amp because despite them being called rail-to-rail, they can't really reach the rails. Close but not actually reach.Here's the very useful "Op Amps For Everyone". It talks about EVERYTHING related to op amps. My favorite chapter is #4 where the discussion centers on offset and scaling. How to get different output voltages for various input ranges.https://www.cypress.com/file/65366/download

author: David Hess
author_rank: Super Contributor
timestamp: April 10, 2019, 07:04:45 pm
content: Quote from: baksuz on April 10, 2019, 02:02:59 pmThey are called instrumentation or difference amplifiers. They can be used to translate and amplify a differential input and reference it to a common which is typically but not always ground.

author: mitrynicolae
author_rank: Contributor
timestamp: April 10, 2019, 07:10:36 pm
content: Please check my last post from this topic:https://www.eevblog.com/forum/beginners/need-help-with-instrumentation-amplifier/I believe it is what you are looking for.
Deflection yokes - More efficient as power thief, ammeter or scrap? - Page 1
Forum section: electronics / beginners

author: Cliff Matthews
author_rank: Unknown
timestamp: May 06, 2015, 03:04:38 am
content: Just cleaning up a bit and found 10 matched 4" TV yoke ferrite cores (I sold the copper scrap long ago). I had thought of making 5 ammeters (or inductive power thief's) by combining the pairs and winding 30 turns of older 3-pair AWG-22 cat-3 telco cable on each half. The opening down the center would be big enough for even heavy power cable and I could switch in various series parallel connections to give equivalents of 30, 60, 120 or 180 turns. Perhaps a rough picture can speak better.I know little about magnetics but with the shape as shown, is there any merit to either use?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 06, 2015, 04:18:29 am
content: I suppose. The tests I've done, show the material is pretty crappy. Low permeability or frequency response or something.Think I'd be surprised if you'd get much out of it at 60Hz.Tim

author: Cliff Matthews
author_rank: Unknown
timestamp: May 06, 2015, 11:28:43 am
content: Quote from: T3sl4co1l on May 06, 2015, 04:18:29 amThanks Tim, I just needed an authoritative push - to the trash (that Sparks thing's really got me moving..)

author: SeanB
author_rank: Super Contributor
timestamp: May 06, 2015, 07:56:31 pm
content: Don't trash it, put it in with the sub grade steel. That way it comes back as a tin can.

author: Cliff Matthews
author_rank: Unknown
timestamp: May 06, 2015, 10:08:38 pm
content: Quote from: SeanB on May 06, 2015, 07:56:31 pmDone. We call sub-grade steel "shred" here, but I can only get $160 a ton (I guess every bit counts).

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 06, 2015, 11:04:55 pm
content: FWIW, the most common grade of ferrite is chemically manganese zinc ferrate(III). So it's oxides, not steel; and contains metals other than iron. In small amounts, mixed with whatever's needed to balance the oxides, it probably won't matter in a steel melt (the zinc will evaporate and the manganese, as long as it ends up reduced as well, will probably tend to improve the alloy). Or it melts into slag and no one minds.It's probably more than a little disingenuous to call it "sub grade steel", but in the quantities that might be found in salvage, it's probably pretty neutral. So, just don't put heaps of the stuff in there.Tim

author: TopLoser
author_rank: Unknown
timestamp: May 06, 2015, 11:41:28 pm
content: Quote from: SeanB on May 06, 2015, 07:56:31 pmGASP!!!my biggest customer for the last 15 years has been Crown Holdings! They produce quality metal enclosures worldwide, not TIN CANS!!!Wash your mouth out!!

author: Cliff Matthews
author_rank: Unknown
timestamp: May 07, 2015, 01:35:01 am
content: Quote from: T3sl4co1l on May 06, 2015, 11:04:55 pmWell it's just 5lbs. out of 500lbs of shred I'll be turning in. Last time they paid me for aluminum sheeting when I clearly had aluminum extrusions. As they say, it all comes out in the wash..
Delay line IC - digital - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: April 14, 2015, 09:58:00 am
content: I am looking for delay line IC for digital signal.I have some signal which I want to delay in us range (0-999us) with 1 us increment1. I have looked at DS1100-500, that is good but its only for 500ns.I can cascade some IC in series to generate delay in us but not for large signal.2. For us range I have checked LTC6994-2. It is good IC. Only problem is if I try to delay both edges, the input pulse width can never be less than tDELAY, otherwise no output signal is generated.Tdelay is time set for generating delay.e.g if set 20us delay, & I send a 1us input pulse, then IC removes it & generate no output instaed of delaying.3. On net I have checked many IC all have delay of picosecond or nanosecond.4. I want IC to be discrete or programmable by discrete components like LTC6994-2 set delay by selecting resistor value.

author: daqq
author_rank: Super Contributor
timestamp: April 14, 2015, 10:01:36 am
content: That's a difficult one - what kind of signal do you wish to delay?You could make your own (microcontroller/FPGA) that would sample and store its input and then release it after the set amount of time.

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: April 14, 2015, 10:37:11 am
content: Normally a pusle signal.I have to make this using discrete IC only.AFAIK, I have to use multiple IC

author: Grapsus
author_rank: Regular Contributor
timestamp: April 14, 2015, 01:45:00 pm
content: Like daqq said you need to know exactly what you are delaying. It's easy to delay a train of 100ms wide pulses by 1ms, but it's a different story for a 1 GHz signal. It's related to the input signal bandwidth. With basic information theory you have "channel_memory = delay x bandwidth", so with a 1 GHz NRZ signal delayed by 1 ms you have to store 1 Mbit of data somewhere.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 15, 2015, 12:15:25 am
content: Yeah, so what's the maximum pulse repetition rate and minimum pulse width?
Delay on make/time delay relay w/ fast reset time - Page 1
Forum section: electronics / beginners

author: xtreme_exploder
author_rank: Newbie
timestamp: June 03, 2020, 09:56:32 pm
content: I have a circuit that requires me to trigger a relay after a 12v signal had been present for a specified amount of time (about .4-.5 sec). I tried using a Airotronics THCU102S3E "delay on make" solid state timer relay wired between the signal box and the relay trigger terminal, but the function wasn't what i needed. It worked fine as long as there was enough time between signals, but would trigger if multiple signals shorter than the desired trigger time were present. I figured out that this was due to the reset time of the device, which is listed as 200ms during the timing cycle or 25ms after the timing cycle.The desired function is this: the signal reaches the relay trigger only if it has continuously been on for the amount of time I want (.4-.5 sec), and stays triggered until the signal is off. If the signal turns off, even for an instant before the time interval I want, I want the time interval to reset and the relay not to come on until the next signal of the set time interval is present. I'm changing it so that a 5v/2mA signal triggers it instead of the 12v previously. I want it to function like the relay timer I tried, but with a much shorter reset time during the timing cycle. Does something like this exist? I tried searching for other delay on make relays but haven't come across anything that looks like it'll work. BTW, the 25ms reset time after the timing cycle is acceptable to me, but not the 200ms during the timing cycle. I know I could program a microcontroller to do this, but I want to make it as simple as possible and avoid that if i can.

author: calzap
author_rank: Frequent Contributor
timestamp: June 04, 2020, 06:29:20 pm
content: Look into Macromatic TE881 and TD8 programmable timing relays. Sometimes using two timing relays serially can provide additional functions.Mike in California

author: picclock
author_rank: Contributor
timestamp: June 05, 2020, 06:06:03 am
content: Only way I can think of without using a micro is to use discretes. Use an RC filter for the incoming signal and reset the capacitor using an FET to discharge it. Activate the relay when the rc level ~60%, using a comparator or zenor. Its mucky but will work.It may be possible to do something with a 555 timer or retriggerable monostable.Alternately, use a small uP.Best Regardspicclock
Delayed temporary signal - Page 1
Forum section: electronics / beginners

author: mf7480
author_rank: Newbie
timestamp: January 24, 2020, 07:33:26 am
content: Good morningI’m new here so excuse the very basic layman’s terms, but the crux of what I’m looking for is a device to enable a one second signal after a one second delay of a proximity sensor activating, and again a one second signal after a one second delay from when the same proximity sensor deactivates.I have 24 of these units in total to do, but they must all work independently, although if one controller could do the lot wiring to a central point wouldn’t be a problem. It’s a 12v system.Looking to make this work as simply and cost effectively as possible.Many thanks in advance for your help, if your need any more clarification please do ask.Best regardsMF7480

author: jmelson
author_rank: Super Contributor
timestamp: January 24, 2020, 11:30:40 pm
content: Quote from: mf7480 on January 24, 2020, 07:33:26 amYou could use an XOR gate and an RC delay to create a pulse on both state changes of the sensor, and then a one-shot to generate your one second delay, and another one shot to generatethe one second pulse width. The CD4070 XOR gate can run off of 12 V directly. The 4538 dual one-shot can also run off 12 V. Make sure to get the real CD4xxx series, not the 74C4xxxwhich are only good to 5 V.To make the edge detector, put the sensor signal directly into one input of the XOR. Use a resistor in series to the other XOR input, and a small capacitor to ground at that input. This causes adelay on that input, and the gate responds with a positive pulse when the two inputs are different. The choice of R and C values need to be chosen for the rise and fall times of the sensor output.Look up the datasheet for the 4538, it's more than I want to explain here.Jon
Dell 1355cn printer paper jam error and no paper visible... - Page 1
Forum section: electronics / beginners

author: The Machiavella
author_rank: Newbie
timestamp: December 15, 2013, 11:13:49 am
content: Dear Eevblog.com Forum MembersI hope very much someone may be in a position to assist further?I am trying to clear error code: 077-900 [Open rear cover Remove paper jam.]This error message has remained after a recent jam. I am fairly certain that there are no fragments left behind after removing the piece - however; I am uncertain as to how I should actually go about removing the toner/drum unit and to ensure this is the case? and if this does not clear the error - how best to proceed from that stage?I did perform a recommended diagnostic being: "To test the registration sensor, you need to enter Customer Diagnosis mode on the printer. To do this: 1. Power off the printer 2. Press and hold the UP and DN arrow keys while powering on the printer; the buttons may be released when the LCD indicates "Diagnosing". 3. LCD should indicate "Customer Mode" and "ESS Diag" (or something similar). 4. Press the DN arrow to display "IOT Diag"; press the ENTER button. 5. LCD should indicate "IOT Diag" and "Digital Input"; press the ENTER button. 6. Press the UP/DN buttons until the desired DI-xx is shown, then press the ENTER button to execute the test. The test we want to run is the Regi-Sensor test -- DI-3. Press the up arrow until the LCD indicates "DI-3 OFF" then press the enter button. The LCD should now indicate "DI-3 L 0"."The result indicated: "DI-3 L 0".I have tried removing toner cartridges and rod cleaning.I have tried a hard reset of the printer.I have not been able to ascertain where the registration sensor is located and where paper enters the sensor area? If possible: an image of what I should be looking for would be beyond awesome! I am a complete novice at this![And admittedly: WAY OUT OF MY LEAGUE HERE BEYOND THESE VERY BASIC ATTEMPTS...]I was able to read an old related post that did have diagrams [unfortunately – the corresponding links to those have long since expired] it did however suggest you could: "toggle the regi-sensor positioner and get the display to change from L to H to L, continuously, then you've cleared the jam. The number will increment indicating how many times you've cycled the positioner. If you need better access into this area, remove the Toner/Drum carts and set them aside."This is something I am yet to attempt as I am oblivious as to how to remove the Toner/Drum cart...Any and all advice would be so very deeply appreciated!Thank you for taking the time to review and further consider my dilemma and wishing you all a spectacular Holiday Season.
Dell 48Wh Battery circuit - Page 1
Forum section: electronics / beginners

author: AjA
author_rank: Contributor
timestamp: December 31, 2017, 07:12:27 am
content: Hello,Below Pics are my Dell laptop battery circuit board where i circle in yellow mark, since i don't know what is this part, so i am wondering if anyone know what is work of said thing on circuit,why i want to know this, here is reason,i open battery to change its old cells with new and i did changed but after finished soldering new cells i find out i loss these two small wires from circuit board that place some where, i search alot on my table but not found, than i put two wires my own & try to check battery but after that battery not working & Dell Laptop showing battery is bad, so i am sure this thing is responsible & what i put two ordinary wires not working as per circuit it should work, so if anyone help me to tell what is this so i buy one new from computer hardware store & replace it,Hope will get some help from someone who know what i am asking,Thanks.

author: ealex
author_rank: Frequent Contributor
timestamp: December 31, 2017, 08:26:05 am
content: that might have been a thermistor - the controller uses it to sense the pack temperature.i don't think it will allow charging without it - the controller will see a battery way to hot or way to cold, depending on how it's implemented.also, it's not clear from the picture - but did you solder straight on the battery body ?

author: AjA
author_rank: Contributor
timestamp: December 31, 2017, 09:12:47 am
content: Hello ealex,Thanks for head-up, no i not solder it on cell body, since original was not solder on cell body but just glue tape on cell body, in same way i also did but not working, as noobi i just solder two simple wires & thinking it should work, anyways what is my alternate, where can buy this thermistor so i solder it on same place, how i let this battery workable again?, i try to search schematic of this circuit but not found anywhere, this is circuit board number printer on it (HF CK 77-1 3 94v-0)that thermistor was looks like this below pic,your help will be appreciated,Thanks.
Dell inspiron 1525 CCFL inverter driver pinout (MP1028) - Page 1
Forum section: electronics / beginners

author: Molenaar
author_rank: Regular Contributor
timestamp: May 05, 2016, 07:38:09 pm
content: Dear all,I would like to use the CCFL inverter of my girl friends old broken laptop as a HV source. However, I cannot find the datasheet of the 20 pins controller (MP1028EF) for the life of me. I found datasheets of the 1026 and 1029, but those appear not to be pin compatible, since the pins which should be enable on the 1026 and 1029 are not connected to a pin on the connector. Does anyone know the pinout of this IC?Thanks in advance!
Dell OptiPlex GX270 desktop - won't start up. - Page 1
Forum section: electronics / beginners

author: Analogdevice
author_rank: Contributor
timestamp: February 14, 2016, 09:12:40 pm
content: Hello friends,I've got a problem with this one and looks like a step down converter on CPU. When I plug PC into mains and press the ON button, power LED lights amber, HDD LED lights and diagnostic LEDs are off. Hard drive won't start up when IDE is connected. Chipset inside and CPU are cool. After few attempts computer goes ON normally, everything works fine. After that the computer is OK, I can turn off and back on machine and its OK. But when I unplug device from mains and after some time plug it back, the problem repeats.I updated BIOS to version A07 (last version), battery is good (3V), power supply gives voltages in tolerance without ripple.Any ideas?Thanks!

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 14, 2016, 09:34:48 pm
content: Check the caps around the CPU, I brought one back to life replacing a few of those.

author: edpalmer42
author_rank: Super Contributor
timestamp: February 14, 2016, 09:39:30 pm
content: When a PC has trouble turning on, it's often a problem with the 5V Standby power from the power supply. Check the voltage with a scope if possible for correct value and minimal noise/ripple. If there's a problem there, check the power supply for bad capacitors. Use appropriate caution when working on the power supply. Line voltage is present in there.

author: Analogdevice
author_rank: Contributor
timestamp: February 14, 2016, 09:51:24 pm
content: Caps around CPU are OK (they have approx. 1780uF from 1800uF).Standby voltage is present, real voltage is 5,1V without ripples. There isn't problemDon't worry, I'm qualified electrician up to 22kV.

author: wblock
author_rank: Regular Contributor
timestamp: February 15, 2016, 02:05:23 am
content: Quote from: Analogdevice on February 14, 2016, 09:51:24 pmCaps can keep their capacitance while the ESR goes high, making them incapable of absorbing ripple.QuoteWithout ripple at all? Most PC power supplies have easily-measurable ripple. 10 mV would be pretty good. How are you measuring it?Look in the power supply. Failed caps do not always bulge, but usually there is more than one, and some will. And the Wikipedia page on the Dell Optiplex specifically mentions the GX270 for failed caps:https://en.wikipedia.org/wiki/Dell_OptiPlex

author: crispy_tofu
author_rank: Super Contributor
timestamp: February 15, 2016, 02:38:56 am
content: Quote from: wblock on February 15, 2016, 02:05:23 am+1GX270s are notorious for capacitor issues, I had a few that blew up. Unfortunately I don't own them anymore...

author: AKM
author_rank: Contributor
timestamp: February 15, 2016, 10:43:24 am
content: How do the capacitors in the PSU look like?

author: Analogdevice
author_rank: Contributor
timestamp: February 15, 2016, 12:55:38 pm
content: Quote from: wblock on February 15, 2016, 02:05:23 amESR was approx. 800mOhm, measured by RLC bridge at 100Hz.Without ripple means that ripple was less than 5mV, measured on Fluke 123 with AC coupling in input.I look to the power supply for the caps, thanks.
Delta ADP180NB laptop adapter PFC ic - Page 1
Forum section: electronics / beginners

author: feridunb93
author_rank: Newbie
timestamp: May 14, 2025, 12:16:55 am
content: Hello, I have a Delta ADP-180NB model laptop adapter. Its PFC integrated circuit is broken and I am having difficulty finding a new one. There is a DAP019BT integrated circuit and a DAS05 integrated circuit. I could not find any information about these. If possible, can I learn the datasheet and equivalent of both integrated circuits?

author: Konkedout
author_rank: Frequent Contributor
timestamp: May 14, 2025, 03:52:22 am
content: It isPOSSIBLEthat these are ASICs; custom for Delta.So many ICs are made now in Taiwan (TSMC is there) and China.At least in USA it is difficult to economically justify trying to repair a laptop power adapter.

author: feridunb93
author_rank: Newbie
timestamp: September 29, 2025, 11:20:39 pm
content: Hello, I know you are right, but my purpose in doing this is to improve myself in troubleshooting and troubleshooting, and also to avoid throwing away a huge adapter for an integrated circuit that costs 1 or 2 dollars.

author: MathWizard
author_rank: Super Contributor
timestamp: October 01, 2025, 02:46:44 pm
content: IDK what country you are in, but did you check ebay ?

author: feridunb93
author_rank: Newbie
timestamp: October 06, 2025, 02:50:46 pm
content: I found the integrated circuit and replaced it but I have other problems. There is an smd diode in the SOD123 case with only A4 written on it. This is broken and I don't know what happened. Also the 007 smd resistor is cracked. I replaced them with something temporary and the circuit is working for now. Thank you for your interest.
Delta Ds2400-21 Antenna problem - Page 1
Forum section: electronics / beginners

author: christos
author_rank: Regular Contributor
timestamp: September 13, 2014, 01:27:13 pm
content: hello..i found this antennahttp://s27.postimg.org/r89y1j70z/asasasasasas.jpgand i found the diagram for it and i was wondering how big this is,so i made a copy of it and was really big.http://s30.postimg.org/xa3qzezgx/IMAG2165.jpgit uses 4 X A4 paperis it normal??its for 2.4 ghz wifisome of the dimensions don't match up for 2-4 mmhere is the file in pdfhttp://125.160.17.21/speedyorari/view.php?file=orari-diklat/teknik/2.4ghz/antenna/2.4ghz-patch-21dBi/DS+2400+-+21.pdf
Delta transformer specs? - Page 1
Forum section: electronics / beginners

author: MadMaxGR
author_rank: Newbie
timestamp: April 29, 2020, 07:16:49 am
content: Hello everyone,I have this Delta Transformer (inverter?) that is somehow blown in a PS4 PRO Power supply. It seems this is the only fault on the power supply and it would work again. I cannot find it anywhere to buy a replacement, so I have the following questions:a. Do you know where I could buy a couple of those a an affordable price? Shipping to Europe is essential.b. Is this damage repairable? I have copper foil on hand.c. What are the specs of this transformer? I couldn't find them, what alternatives to this, can I use? (Delta website has no info on this, or I couldn't locate any anyway)I hope you have the answers for the above.Thank you!

author: MadMaxGR
author_rank: Newbie
timestamp: May 04, 2020, 02:06:01 pm
content: Anyone could help wit the above? My only chance is to find another power supply and swap the transformer? Is this really my only option?

author: jmelson
author_rank: Super Contributor
timestamp: May 04, 2020, 04:10:40 pm
content: How do you know this transformer is bad? What tests did you do?It is more likely that some other component -- rectifier, power FET has gone bad than the transformer.These switching transformers are pretty much all custom parts, made to the spec of one of their customers. You won't find them in a catalog.Jon

author: MadMaxGR
author_rank: Newbie
timestamp: May 04, 2020, 08:01:36 pm
content: Quote from: jmelson on May 04, 2020, 04:10:40 pmHi Jon,As you see the attached pics, the transformer is blown. It is "ripped".

author: calmtron
author_rank: Regular Contributor
timestamp: May 05, 2020, 06:27:49 am
content: It looks like someone has ripped open the electrostatic shielding on the transformer. I don't see any soot, burned areas or other traces of an explosion. It should work without the shielding. Perhaps it was forming a shorting turn and was sloppily fixed in production? Or have you cleaned up all the soot?The transformer is commonly custom made for the power supply model so the easiest source should be another PS4 Pro power supply.

author: MadMaxGR
author_rank: Newbie
timestamp: May 05, 2020, 08:58:18 pm
content: Quote from: calmtron on May 05, 2020, 06:27:49 amYou are right, the transformer works and the fault was a diode which I have located today. The Power supply is working stable now. All good. Thanx for the assistance.