hybridfree/eevblog-posts huggingface dataset:
Analog ICs don't work in Proteus - Page 1
Forum section: electronics / beginners

author: bborisov567
author_rank: Regular Contributor
timestamp: December 06, 2022, 02:25:51 pm
content: I have a problem when simulating analog ICs. I tried LM358, OP1177, LM311 but no matter what i put on the inputs there is always 0 volts at the output. I upload a project with LM311. What am i missing? Is there a setting that i have to change or there is a problem with teh libraries?

author: Wolfram
author_rank: Frequent Contributor
timestamp: December 06, 2022, 02:48:56 pm
content: How is VDD configured? It would be good to verify with a voltage measurement that the VCC is present and of the correct value.The LMx11 is configured as an open collector output here, and there's nothing pulling the output voltage up. A pullup resistor to VCC, for example 10k, will allow the output voltage to go positive. Also note that having the inputs connected directly to VCC and GND could cause comparators and op-amps to operate incorrectly. There are some parts with inputs that work across all voltages up to the supply rails, but many have a limited range over which they will operate correctly, both in terms of common mode and differential voltage.

author: bborisov567
author_rank: Regular Contributor
timestamp: December 06, 2022, 03:18:01 pm
content: After adding 10k i get the VDD on the output. Also added to potentiometes on the inputs but still the IC is not working.

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 06, 2022, 04:05:05 pm
content: Hint: for quickly getting a power supply of any voltage, write ex. ”+15V” instead VDD.

author: Zero999
author_rank: Super Contributor
timestamp: December 06, 2022, 10:52:58 pm
content: Quote from: bborisov567 on December 06, 2022, 03:18:01 pmThat's because pin 7 is wired hard to +15V. It needs to be connected via a pull-up resistor.Look at the data sheet.https://www.st.com/resource/en/datasheet/lm311.pdfDelete the bottom voltage source.

author: bborisov567
author_rank: Regular Contributor
timestamp: December 07, 2022, 03:08:13 pm
content: It't not a voltage source, it is a voltmeter. I use it to mesure the voltage at the output.

author: Zero999
author_rank: Super Contributor
timestamp: December 07, 2022, 04:29:49 pm
content: Quote from: bborisov567 on December 07, 2022, 03:08:13 pmThat symbol is often used for a voltage source, hence the confusion.Pins 5 & 6 should be left unconnected, if they're not used, rather than connected together.

author: bborisov567
author_rank: Regular Contributor
timestamp: December 07, 2022, 05:40:06 pm
content: I finally got it working. It turned out that 'Attach hierarcy module' was checked. After unchecking it the simulation started working properly.
Analog Multimeter Measuring AC Current ? - Page 1
Forum section: electronics / beginners

author: hgg
author_rank: Frequent Contributor
timestamp: February 24, 2014, 03:46:27 pm
content: I am trying to find an analog multimeter that can measure AC current but I cannot find one.There are however analog panel displays for AC current sold in ebay like the following:http://www.ebay.com/itm/Class-2-5-Accuracy-Current-AC-200mA-Analog-Panel-Meter-/321063547608?pt=LH_DefaultDomain_0&hash=item4ac0e0f2d8Do you know in what way there are different from the DC current displays?Will I be able to use an analog multimeter to measure AC current?I have already bought one AC current panel display but if I can find an analog multimeterthat can measure AC current it would be great because I will use the housing for myproject and the panel would be perfect for measuring signal strength which in my caseis AC current.Thank you.

author: KJDS
author_rank: Super Contributor
timestamp: February 24, 2014, 03:58:17 pm
content: AVO 8 MkV and mkVI have Ac current ranges from 10mA to 10A

author: hgg
author_rank: Frequent Contributor
timestamp: February 24, 2014, 04:12:20 pm
content: So it does exist! Its very rare though.Do you know if I will be able to use the panel from a DCA analogue multimeter to measure AC current?

author: rsjsouza
author_rank: Super Contributor
timestamp: February 24, 2014, 05:02:19 pm
content: The ICE supertester series (680R, 680G) also has AC measurements (I grew up using a 680R from my dad). One thing I liked was their huge display (checkthis thread)They can be obtained for cheap on ebay, especially since you are located in Europe.

author: hgg
author_rank: Frequent Contributor
timestamp: February 24, 2014, 07:51:16 pm
content: That's a really nice multimeter!

author: carpelux
author_rank: Regular Contributor
timestamp: February 24, 2014, 08:37:41 pm
content: The Unigor 6e measures AC current down to 1uA full scale.It's a FET meter, with high impedance and is one hell of a meter.http://www.drkfs.net/UNIGOR.htm

author: qno
author_rank: Frequent Contributor
timestamp: February 24, 2014, 09:04:41 pm
content: The unigor is a nice meter, it not FET but transistor.It works with a choppers and an AC aplifier.It can measure 1 uA to 3 A ac currrent.You can also look for an Philips PM2504.It can measure 1 mA to 32 A AC.
analog multiplier using log and antilog amplifier issue - Page 1
Forum section: electronics / beginners

author: rocker
author_rank: Newbie
timestamp: December 01, 2017, 06:56:38 pm
content: I'm trying to build an analog multiplier that takes any two voltages and produces the product for themThis is the basic layout of the circuit:can this layout do what I need? I know there is a problem with the last stage, the last opamp should give me gain: k2, to get V1 * V2 but I don't know that the value of k2?
Analog oscilloscope  - Page 1
Forum section: electronics / beginners

author: jose347
author_rank: Contributor
timestamp: October 16, 2018, 03:45:33 pm
content: Hi all,I'm looking for an Analog oscilloscope model perhaps tektronix or hp, that has widely documentation and parts available, I'm not looking at much speed neither something to break the bank, but a model I can get broken and use as a debugging project to finally have an analog oscilloscope around?any suggetsions?thanks in advance

author: GeoffreyF
author_rank: Regular Contributor
timestamp: October 16, 2018, 03:52:24 pm
content: I think that a modern low end scope would actually be a better purchase. A scope like the Rigol 1052 has a price comparable to analog scopes on ebay and it's more useful.

author: N2IXK
author_rank: Frequent Contributor
timestamp: October 16, 2018, 03:57:04 pm
content: A Tektronix 453 or 454 would be a good choice. Easily available, fairly small/portable, and very few unobtanium custom components which are prone to failure.The 22xx series were also good (and a good bit newer), but some parts are getting hard to find.

author: jose347
author_rank: Contributor
timestamp: October 16, 2018, 03:59:30 pm
content: Quote from: GeoffreyF on October 16, 2018, 03:52:24 pmThanks but I already own a DSO, I just looking to have an analog scope

author: jose347
author_rank: Contributor
timestamp: October 16, 2018, 04:00:17 pm
content: Quote from: N2IXK on October 16, 2018, 03:57:04 pmI will look into them, Thanks

author: Wimberleytech
author_rank: Super Contributor
timestamp: October 16, 2018, 06:14:01 pm
content: Quote from: jose347 on October 16, 2018, 04:00:17 pmTek 465B would be my choice. I own one.

author: tggzzz
author_rank: Super Contributor
timestamp: October 16, 2018, 07:47:33 pm
content: Quote from: jose347 on October 16, 2018, 03:59:30 pmGood; that will avoid many standard responses.I have too many old scopes. The key point is to get one that you can see working - all the channels/sensitivities, all the timebase speeds, triggering, and dual timebase.HP1740s are surprisingly cheap, equivalent to much more expensive Tek 465s. There are other HP17xx, but I don't have any experience of them.Tek 465s, 475s are good but expensive; I prefer my Tek 485 since it has proper 50ohm attenuators, 350MHz, and will trigger off a 1GHz signal. I dislike the bolt-on DMMs, since they make it more difficult to repair.Tek 24x5s are good, but are fragile in some ways and one of the ICs is difficult to obtain.Tek 22x5s are cheaper production line equivalents of the laboratory 24x5s. I don't like the timebase controls, but they work.Other less interesting scopes: assume £1/MHz.
analog panel ammeter, do I need a current shunt? - Page 1
Forum section: electronics / beginners

author: XOIIO
author_rank: Super Contributor
timestamp: June 25, 2014, 01:03:09 am
content: Pretty quick and simple question, I got a 30 amp panel ammeter off ebay to measure stuff more than 10 amps, I was wondering if I need a current shunt with these, or if I can just pass it directly through (for example measuring how many amps a transformer can give while short circuited).I'm also curious if they will work with AC as well. I have a transformer that can give a load of AC current, but I'd like to see how much. I have a feeling it would fry the meter though.

author: eetech00
author_rank: Regular Contributor
timestamp: June 25, 2014, 03:13:44 am
content: Quote from: XOIIO on June 25, 2014, 01:03:09 amHiWe need more info. Can you post a picture of the front and back of the unit? or a model number?eT

author: XOIIO
author_rank: Super Contributor
timestamp: June 25, 2014, 07:18:31 am
content: This one is the one I purchased (or one listed in exactly the same way) and it's physically identical aside from some markings.http://www.ebay.ca/itm/Stone-New-Professional-Analog-Panel-AMP-Meter-AC-DC30A-Ammeter-High-Quality-/171237916734?pt=LH_DefaultDomain_0&hash=item27de93403egot to love the wealth of info from ebay sellers.

author: XOIIO
author_rank: Super Contributor
timestamp: June 25, 2014, 07:48:14 am
content: Quote from: wilfred on June 25, 2014, 07:35:54 amAlright, nice to know it's an all in one package, I could pop it open to see but don't want to risk damaging it.

author: Rerouter
author_rank: Super Contributor
timestamp: June 25, 2014, 07:51:50 am
content: try sticking a multimeter across it, if the rectifier is just for the coil then it should measure near a short, if the rectifier is on the shunt the diode check function should show 2 diode drops,then for the rectified unit might be worth feeding some tiny current through it to see if it deflects or not,

author: electrophiliate
author_rank: Regular Contributor
timestamp: June 25, 2014, 08:20:00 am
content: I have a 30A DC ammeter which did not need a (external) shunt:http://www.ebay.com/itm/DC-30A-Analog-Ammeter-Panel-AMP-Current-Meter-85C1-0-30A-DC-Doesnt-Need-Shunt-/171140378843

author: XOIIO
author_rank: Super Contributor
timestamp: June 25, 2014, 10:57:27 am
content: Well, unfortunately it seems to be a "dumb" one, no voltage drop, tests as a straight short, and taking it apart seems to confirm that. Threw 5 amps through it, and it really only rose to around 1.5 or 2 amps on the meter :/
Analog panel meter fix? - Page 1
Forum section: electronics / beginners

author: ikrel
author_rank: Contributor
timestamp: October 31, 2012, 11:15:47 pm
content: I just got a panel meter in a grab bag, however i can't adjust the meter to zero. Does anyone know how i might be able to fix it?

author: Psi
author_rank: Super Contributor
timestamp: November 01, 2012, 12:12:47 am
content: So the zero-adjust screw does nothing?or it adjust the needle but cant get back to zero?If you take the case off you might be able to fix it, depending on what the problem is.

author: ikrel
author_rank: Contributor
timestamp: November 01, 2012, 12:14:10 am
content: It will adjust but not go to zero. in the pic it's as close as it will get.

author: pickle9000
author_rank: Super Contributor
timestamp: November 01, 2012, 01:19:21 am
content: By chance can you adjust the needle to be dead center? If so it may have the wrong faceplate on it....mike

author: ikrel
author_rank: Contributor
timestamp: November 01, 2012, 01:26:46 am
content: I can center but it's at the extreme end of the adjustment

author: Psi
author_rank: Super Contributor
timestamp: November 01, 2012, 01:42:17 am
content: I'd take the top off and have a look at the center adjustment.The spring may have slipped a few turns (hard to fix) or it may have a plastic stop for the adjustment screw which you can easy bypass.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 01, 2012, 01:44:10 am
content: That's why it was in the "grab bag".If you take the face off,you may find that the extension on the bottom of the coil which is meant to fit over the adjustment pin,is bent,so lacks adjustment.You may be able to straighten it,or just set the zero & put the face back on.
Analog switches and SDIO/SPI devices - Page 1
Forum section: electronics / beginners

author: ledtester
author_rank: Super Contributor
timestamp: September 23, 2020, 07:03:26 pm
content: I was wondering if an analog switch such as the TS3A5018(datasheet)would be suitable for switching the SDIO/SPI interface lines between two SD cards.In this case data is written to the SD card at about 100 MB/minute.The datasheet says the bandwidth of the TS3A5018 is 300 MHz into a 50R load. Would that also be indicative of its performance in this application?This is an idea to off-load data from a camera by electronically switching between two SD cards.

author: julian1
author_rank: Frequent Contributor
timestamp: September 23, 2020, 09:08:25 pm
content: Why analog. Do you want to send over fixed impedance line? Why not a digital transceiver. The SD cards on arduino breakouts commonly rely on LVC245A.

author: rstofer
author_rank: Super Contributor
timestamp: September 23, 2020, 10:16:50 pm
content: Can't they both share the bus and just use the SS Slave Select line?

author: ledtester
author_rank: Super Contributor
timestamp: September 23, 2020, 10:45:17 pm
content: Quote from: rstofer on September 23, 2020, 10:16:50 pmI want to access the other card from another microcontroller. And I can't modify the firmware of the camera.QuoteIt could be done with 4 transceiver chips. Possibly could be done with 2 if I give up the ability of independent HI-Z control.Think of it as a camera writing to card #1. Then it is redirected to write to card #2 while a microcontroller connects to card #1 to process the data. And then another switch happens, etc.

author: David Hess
author_rank: Super Contributor
timestamp: September 24, 2020, 02:45:41 am
content: Yes, analog switches can be used as digital multiplexers in most digital applications and may even be preferred in some cases.
Analog to digital help - Page 1
Forum section: electronics / beginners

author: DuWong
author_rank: Newbie
timestamp: March 16, 2018, 09:57:57 pm
content: Is there a way to use an arduino to be able to read an analog signal of 0 to +30V? I know the arduino can only go up to +5v, I think it would it be possible to voltage divide the analog signal but wouldn't that lose a lot of precision? Or how could I use another circuit to convert it from analog to digital?

author: Zero999
author_rank: Super Contributor
timestamp: March 17, 2018, 12:04:16 am
content: Yes, use a potential divider to reduce the voltage. There will be some loss of precision, but 1% resistors are normally good enough. In any case, there's no point in exceeding the specifications of the ADC or reference.Here's a site with a handy potential divider calculator tool. Obviously the results can be multiplied by a factor of 10, to get the desired input impedance.http://sim.okawa-denshi.jp/en/teikokeisan.htmOne thing to note is that the ADC takes a current spike, when a sample is taken, as the sample and hold capacitor charges. If the potential divider's output impedance is very high, this can upset the reading. One solution, to minimise loading on the circuit being measured, is to keep the potential divider's resistor values high and add a capacitor between the ADC's input and 0V. Unfortunately this reduces the bandwidth, so is only useful for low frequency signals.

author: Shock
author_rank: Super Contributor
timestamp: March 17, 2018, 05:15:29 am
content: Opamp based solution here.https://electronics.stackexchange.com/questions/266737/high-voltage-sampling-with-microcontroller-potential-divider-affecting-signal

author: Zero999
author_rank: Super Contributor
timestamp: March 17, 2018, 02:54:38 pm
content: Quote from: Shock on March 17, 2018, 05:15:29 amYes, that will work, just ensure the common mode input range of the op-amp isn't being exceeded, so R401 might need to be skipped, to ensure the supply voltage isn't higher, than the inputs. In this case, the input signal can be up to 30V, so you need an op-amp with a rail-to rail input. A quick look through the RS catalogue yielded the following: LM7322, LT1638, ADA4091, LT1490A.
Analog trace width discontinuity but same impedance. - Page 1
Forum section: electronics / beginners

author: Vcky_electro
author_rank: Contributor
timestamp: July 25, 2019, 03:30:26 pm
content: Hi,I'm using GPS SMA connector with 50oHM trace as shown in the image. Where the trace width is very tiny compared to the SMA connecter's pad . What my doubt is, will the tiny trace width affect the signal flow ?? my thought is the trace width need to be same as the pad width for the flow will be better and VSWR will be better. is my understanding correct ?? if i do like that i cant achieve 50 ohms. so what would i do ??Awaiting for anyones reply..Thanks .Vicky

author: eb4fbz
author_rank: Regular Contributor
timestamp: July 25, 2019, 03:47:22 pm
content: You should remove GND plane underneath the connector pad to compensate that. However look at the SMD components too! Their pads are very big compared to the 50ohm line. Maybe you should change board stackup.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 25, 2019, 04:22:18 pm
content: Neither is a huge problem at λ/4 ~ 70mm. The change in transmission line impedance is modest, and the length is short compared to the wavelength.The pads may be interesting in their effect on detuning a filter, if present. As mentioned, they are quite large relative to the trace width.No stitching vias?Tim

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 25, 2019, 06:00:31 pm
content: Quote from: eb4fbz on July 25, 2019, 03:47:22 pmi think thats to reduce capacitance? hi-freq + a capacitance = LPF? (disclaimer = i'm not the expert)
Analog Video Keyer - Page 1
Forum section: electronics / beginners

author: bopstar
author_rank: Regular Contributor
timestamp: January 25, 2018, 01:52:10 am
content: Hi i am a part time builder of analog video (though still a beginner) gear but it stuck me that i haven't delved into keying before. i understand the fact the two key signals must be synced and that no problem for me. what i am looking for is what is the required mixing circuitry required to do basic LUMA Keying. i though for a bit and i could use a LM1881 to produce a high contrast black and white image winch can become the key signal and then an OP AMP with the regular video signal going through an inverter. tell me what you thinkKind Regards,Bopstar

author: BrianHG
author_rank: Super Contributor
timestamp: January 25, 2018, 02:26:44 am
content: You will need an analog delay line to compensate for the delay between the comparator you are using for the key.Look for comparators which will operate really fast.LM1881 is a sync separator and is really too slow for you as a switch, but is still good for sync separation and DC restoration clamp placement.I would use first a NE592, powered to the maximum safe +/- voltage, + use a sync separator with DC clamp at the color-burst on the source and again output. You need to maximize your gain to just before clipping (aim for x4 video level, or 4vp-p), for each source signal so that you have a parallel set of sources all with the same DC reference voltages regardless of video source content. Regular high speed op-amps only mess things up when applying any gain above 2 to NTSC/PAL video signals. (Color goes off at the extreme saturation levels even with really fast video op-amps)Then search for the fastest comparator possible and fastest analog switch. Use 1 input to adjust the stencil level with the other containing one for the video outs from the NE592...Then analog delay each source so that the video through matches the comparator delay + your analog switch's input setup delay, otherwise, you will have a white/black trim around your objects unless you are using a dedicated stencil video source channel where you can tune the horizontal offset. (You generally loose 1/2 your video level in an analog delay line, so, now you are at 2vp-p)Emitter-follower/buffer output and series 75 ohm the 2Vp-p video which will become 1Vp-p when loaded with 75 ohm load. (With the 2 1/2 video losses in your system, this is why you want to initially boost your video sources to 4Vp-p...)You should be able to work out the rest...
[solved] Analog voltage level conversion - Page 1
Forum section: electronics / beginners

author: mnt22
author_rank: Contributor
timestamp: December 25, 2020, 07:02:34 am
content: Hi everyoneI'm trying to convert 0-10 VDC TO 1-5 VDCthe tricky part is the conversion 0v to 1v by using electronic circuit not using any type of controller.Thanks for the help

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: December 25, 2020, 09:36:33 am
content: using op-amps without any further circuit optimization:(pardon my gimp-fu or lack thereof)

author: Zero999
author_rank: Super Contributor
timestamp: December 25, 2020, 10:55:12 am
content: Quote from: Le_Bassiste on December 25, 2020, 09:36:33 amThis can be done passively, assuming the input/output impedance don't need to be excessively high/low.Quote from: mnt22 on December 25, 2020, 07:02:34 amAssuming you have a stable 5V voltage source, all that's required is three resistors, but more may be required to get convenient values.http://www.symres.com/files/scalebias.pdfhttps://electronics.stackexchange.com/questions/22742/combined-adc-scaling-and-offset-with-variable-input-voltage-ranges

author: mnt22
author_rank: Contributor
timestamp: December 25, 2020, 09:04:02 pm
content: The problem not solved because bias is not right with the desired signal it originally for prusser transducer replacement (0-10Vdc) replacing (1-5Vdc) the controller only can read (1-5Vdc)! If there are any ways to mapping this voltage actively or passively?

author: Zero999
author_rank: Super Contributor
timestamp: December 25, 2020, 11:00:53 pm
content: Quote from: mnt22 on December 25, 2020, 09:04:02 pmIt's not clear what you're trying to do.Did you read the links I posted above?If all you want to do is scale a 0V to 10V signal, to 1V to 5V and you have a stable 5V supply, then all you need are three resistors.If you require a low output impedance, then add an op-amp buffer.Here's a site which can calculate the resistor values. It also shows the op-amp buffer, which is only required if you need to drive a low impedance load.http://earmark.net/gesr/opamp/case7.htmhttp://earmark.net/gesr/opamp/gain_offset.htm

author: mnt22
author_rank: Contributor
timestamp: December 26, 2020, 03:20:12 pm
content: thanks Le_Bassiste and Zero999, Your kindness, generosity and thoughtfulness are greatly appreciated.
Analog voltage to duty cycle control using 555? - Page 1
Forum section: electronics / beginners

author: SittingBear
author_rank: Contributor
timestamp: August 22, 2014, 06:09:08 pm
content: Hello EEVBlog Forums,I'm trying to use the voltage output from a peak detector amplifier to convert to a fixed frequency, variable duty cycle signal. I thought about using a micro controller to do this, but that seems like a bit overkill to me and I would rather learn about a possible new use for the 555 timer.The positive voltage rail will either be +5Vdc or +12Vdc with the negative or low rail being 0V / GND. I feel that there must be a simple way of doing this.Any help is greatly appreciated!-Bear

author: David Hess
author_rank: Super Contributor
timestamp: August 22, 2014, 06:54:06 pm
content: How accurate do you want it to be? An operational amplifier can be used to integrate the difference between the desired and output duty cycle.

author: oldway
author_rank: Super Contributor
timestamp: August 22, 2014, 07:04:51 pm
content: You can do this of a very easy way with a TL494 or with a SG1525, but it will not work with +5V, it is too low voltage.They need more than +8V.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 22, 2014, 07:09:22 pm
content: One chip, a handful of resistors. Will work as shown at 5V, though you may want to tweak values to adjust the exact voltage ranges or thresholds or whatever.The ramp waveform is sloppy (exponential curves), so the transfer function won't be linear. You can fix this by using gated current sources instead of R5. R5 * C1 sets the frequency, R1-R2-R3 sets thresholds.Tim

author: SittingBear
author_rank: Contributor
timestamp: August 22, 2014, 07:36:09 pm
content: Sorry. I found the solution, untested, on page 13 ofthisdatasheet. I attempted to delete this thread, but I guess it might have been better to hear other ideas instead of going with an untested method! I'll be able to construct and take measurements of the circuit tonight.Cheers!
Analog vs Digital Function Generators and Frequency - Page 1
Forum section: electronics / beginners

author: Legion
author_rank: Frequent Contributor
timestamp: February 08, 2014, 09:28:50 pm
content: I've seen it stated in many places that it's useful to have both an analog and a digital oscilloscope. Does the same hold true for function generators? Are analog generators better at non-sinusoidal signals? I've read that digital generators drop the max frequency when you get into saw tooth and other functions. Lastly, how do I determine how big of a frequency range I need? Do certain areas of electronics require GHz freqs while other areas are fine in the low MHz?

author: SArepairman
author_rank: Frequent Contributor
timestamp: February 08, 2014, 11:13:26 pm
content: DDS for 90% of things that you would want in lab function generator. It offers a good balance.http://www.ti.com/lit/an/snoa665c/snoa665c.pdfRead table 1 (page 4) to get an idea about different methods of making sine waves.and yea, analog/hybrid will be better at triangle and pulse then a dds in terms of speed. a 1400$ agilent meter will do triangle up to 100KHz, a used 90$ generator from 1985 will do triangle to 10MHz... but the agilent will be more stable and just nicer and more precise.
ANALOG - Page 1
Forum section: electronics / beginners

author: pulkitver1991
author_rank: Newbie
timestamp: August 19, 2014, 07:44:13 pm
content: HOW TO CONVERT THE SMPS PWM OUTPUT OF 50V AND 10A TO CONSTANT DC OUTPUT??I have a smps which is giving 50 volts and 10 amperes as its output, Now i want to display the voltage and the current on the lcd. the problem to be solved is, how to convert the pwm output to constant dc so that the ADC can read the proper current and voltage. i have already made a circuit which can work only if the output is constant.Please help me output with this???

author: idpromnut
author_rank: Unknown
timestamp: August 19, 2014, 08:05:22 pm
content: I would think that if you're seeing a PWM on the output of the SMPS, that the output capacitor(s) on the supply are not doing their job. You will get a bit of switching frequency through, but you should be seeing a basically DC output. Is this an off-the-shelf supply, or are you using a switcher IC?
Analogue circuit - Page 1
Forum section: electronics / beginners

author: zzlong94
author_rank: Contributor
timestamp: December 03, 2017, 03:48:40 am
content: after i run the simulation, based on my circuit.why the output voltage decrease from the beginning and increase after a period of time?shouldn't be the output should be in steady state?

author: danadak
author_rank: Super Contributor
timestamp: December 03, 2017, 11:36:06 am
content: Did you do a wire/node check prior to sim ? Pic makes itlook like MOSFET source may not be wired to groundproperly.Regards, Dana.

author: w2aew
author_rank: Super Contributor
timestamp: December 03, 2017, 03:36:26 pm
content: Quote from: danadak on December 03, 2017, 11:36:06 amor maybe a problem the the V2 ground connection...
analogue resistor-ladder decoder ? - Page 1
Forum section: electronics / beginners

author: carl0s
author_rank: Unknown
timestamp: October 14, 2021, 04:56:40 pm
content: Hi.The steering-wheel buttons in the old car are a resistor ladder.I want to wire them into the various play/next/pause inputs on a CSR8645 bluetooth module.I could use a microcontroller to do this, and I have plenty of them here.But I'm wondering if there is a simple way to do it without an MCU?There would be a single wire in, whose voltage is different depending on what steering wheel button is pressed. Or the single wire might just give a varying resistance to ground, I'm not sure yet and I haven't tested.Then there would be ~4 or 5 outputs.I wonder if the outputs would need to go via relays or something, since the input is on the car's ~14v side, and the output that is being switched is an isolated 3.3v side.

author: Manul
author_rank: Super Contributor
timestamp: October 14, 2021, 05:29:59 pm
content: A few window comparators could be used, but that is overkill. If you go with comparators, you likely need some output filtering, because there could be short glitches, while the input voltage is rising or falling and crossing different "windows". Also it would act as a crude form of debouncing (because you likely need it).I think best is a small MCU with ADC. Then you can adjust "windows" and filtering/debouncing in software. If ladder uses car supply, you also need to monitor that voltage with a separate ADC input to keep thresholds proportional while car supply voltage is changing. I don't know any other ways, which would be robust.

author: carl0s
author_rank: Unknown
timestamp: October 14, 2021, 06:46:56 pm
content: Thank you. I have plenty here too. Lots of esp32, esp8266, Arduino pro mini, pro micro, and some stm32f411. So much choice. Oh and some RPI 2040 and a blue pill too.Pro Micro might be a good fit.

author: tszaboo
author_rank: Super Contributor
timestamp: October 14, 2021, 09:32:06 pm
content: Like an LM3915.
Analysis help needed: MOSFET control circuit for -12V? - Page 1
Forum section: electronics / beginners

author: ankeakala
author_rank: Contributor
timestamp: September 06, 2020, 10:49:38 am
content: Can someone explain what is the purpose of D2 zener in this circuit? As far as I understand, both of those enhancement type MOSFETs are off because both VGS are at 0V when PF0 is floating.And if PF0 is pulled to 0V, P-Ch would then conduct, andpresumablyD2 zener would also conduct because the delta is greater than 5.6V and would pull N-Ch G1 to roughly 5V (turning it on), but how will that R17 to -12V affect that? Would it not pull N-Ch G1 to -12V and the N-Ch would stop conducting? Or am I lacking in my understanding of how negative voltage works?Or is there something else going on?

author: Ian.M
author_rank: Super Contributor
timestamp: September 06, 2020, 11:55:13 am
content: Somebody decided that 17V (5V - (-12V)) was too much for the N-MOSFET gate, so they put in a Zener to drop the gate drive by about 5.5V. The MOSFET is actually rated for +/-20V Vgs for both the N and P channel devices (page 2) so, unless the -12V supply has negative going spikes of over 3v, its not essential. Personally, I'd use a 4K7 resistor there which would form a potential divider with the 10K gate pulldown limiting the gate voltage to about 11.5V , but then I'm cheap like that!You asked what happens with the gate pulldown R17. When the P-MOSFET turns on, the Zener wins (as its slope resistance is *MUCH* less than 10K), pulling up the N-MOSFET gate to approx -0.5V i.e. 5V supply - Zener voltage, (nom. 5.6V, but reduced due to low current through it)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 06, 2020, 02:07:48 pm
content: That. ^FYI, the fuse won't do anything. Fuses blow very slowly, milliseconds. Transistors blow much faster, hundreds of microseconds perhaps.Well, I mean the fuse will still protect the circuit, but only after the transistor has failed shorted, allowing full fault current to dump into the load, through the fuse, clearing it.A better solution is to use a current sensing circuit, and when current goes well beyond limits, simply turn off the transistor for some time. Alternately, a much bigger transistor can be used, that can pass enough current to clear the fuse (but this will be somewhat more expensive, and will have much more gate capacitance, so will switch slower). Also, a bigger transistor can be used in a different way, either with an analog control circuit (a few transistors) or an IC (typically called a hot-plugging, wired-OR or load switching controller), to limit current actively rather than permitting fault currents to flow. Downside is this can dissipate a lot of power (not quite as much as the unlimited fault condition), so some other means of protection is usually a good idea (a time delay or thermal cutout).Tim

author: ankeakala
author_rank: Contributor
timestamp: September 06, 2020, 02:57:01 pm
content: Thanks for the tips and comments. Still not quite clear how exactly it works but at least it seems to work exactly like said. With the Zener the N-MOS gate drive is that 5.5V lower.
Analysis Schematic of a TI design - Page 1
Forum section: electronics / beginners

author: whyshnavy
author_rank: Newbie
timestamp: September 15, 2024, 05:24:22 pm
content: Hi guysnew to this forum and pretty new to hands on electronics experience as well so bear with my extremely basic questionIve been trying to do a project of building this DC DEC Converter using TI's C2000, ( specifically TI Launchpad 'F23837x ' MCU) The schematic attached by TI is a big too complex for me and to make my own on KiCad has been a tad bit challenging, especially i don't get what half of the components are and those i do aren't on KiCad library. And if i do want to replace certain components with similar specifications ( say the given component is out of manufacturing), what am i supposed to do get an accurate result and not mess up the OG circuit. ThanksI've attached the schematic for reference :https://www.ti.com/lit/pdf/tidrhs7

author: Slh
author_rank: Regular Contributor
timestamp: September 15, 2024, 06:23:30 pm
content: Hi, i think you'll get a useful response if you have a specific question. I'm not sure what your actual question is.There's not much in that schematic, it's just the power stage of a buck converter. Nothing more complicated than a gate driver or opamp. Check the data sheets of those parts to see how they are used. TI generally have documents for how to use their reference designs which should give some hints about what the circuits do and how to use the design.

author: whyshnavy
author_rank: Newbie
timestamp: September 16, 2024, 03:01:15 pm
content: This actually helps, thanksMy question, to be specific, was how to proceed using the reference schematic, in case i do not understand what certain components are in the given diagram and that when i try to do the same on KiCad, how do i replace the components that are out of manufacturing or aren't available in KiCad libraryIve checked the data sheet and I have a deeper understanding now, so ty

author: PGPG
author_rank: Frequent Contributor
timestamp: September 16, 2024, 03:34:34 pm
content: Quote from: whyshnavy on September 16, 2024, 03:01:15 pmCertain means all?As you don't ask for specific component what it is so do you expect someone will you explain each component one by one what they are?Quote from: whyshnavy on September 16, 2024, 03:01:15 pmYou certainly have to understand what are the components that are out of manufacturing to know how to replace them.I suggest first to get to state that you know all the components at schematic.Quote from: whyshnavy on September 16, 2024, 03:01:15 pmYou can ask at KiCad forum how to make your own library. See FAQ there.
Analyzing a matching network - Page 1
Forum section: electronics / beginners

author: jmsigler
author_rank: Regular Contributor
timestamp: May 31, 2016, 01:47:18 am
content: Hello, first off I am pretty new to RF/Ham stuff, so this question is pretty basic. I'm trying to figure out if there are any easy/cheep ways to accurately measure the impedance of a matching network attached to an IC? I have made a cc1101 based comms circuit board and would like to see how well the theory design performs in a practical application. As a related question, what is the standard way to measure radiated rf power. I.E. if I know that I am supposed to be radiating 27dBm, what would the best way to measure this be?

author: danadak
author_rank: Super Contributor
timestamp: May 31, 2016, 10:10:22 am
content: If you have a scope and sig gen -http://www.learnabout-electronics.org/ac_theory/impedance73.phpNetwork analyzers commonly used as well.Power measurement google "power measurement rf transmitter". Many lowcost power meters also available, bird power meter. Also circuits you canbuild.http://www.dudleylab.com/Appnote-4-Power-tests1.pdfhttp://cp.literature.agilent.com/litweb/pdf/5965-6630E.pdfRegards, Dana.
Analyzing circuit diagram for 40kHz ultrasound receiver - Page 1
Forum section: electronics / beginners

author: eerocketman
author_rank: Contributor
timestamp: April 12, 2018, 06:28:54 am
content: So I am making an amplifier circuit for a 40kHz ultrasonic receiver. I have found the dev board from AD which does something very similar to what I would like to do. However, I don't even know how to begin analyzing the circuit given. I haven't seen amplifiers in this configuration. Can someone help me analyze this circuit at a high level? I've attached the application notes and a snapshot of the particular circuit in question.Thanks in advance!!!

author: palpurul
author_rank: Regular Contributor
timestamp: April 12, 2018, 07:22:30 am
content: I think I can kind of understand why you can't begin analyzing the circuit. Do you how single supply opamps are biased? Have you ever dealt with single supply opamps in the past? If that's what you are missing once you learn how to bias single supply opamp the first 2 stages would be east to analyze. They are just gain stages with DC bias.

author: 0xfede
author_rank: Regular Contributor
timestamp: April 12, 2018, 09:39:42 am
content: Hi eerocketman,This schematic consists of a two stage amplifier U8A and U8B and a squaring circuit U11.You should try to see the circuit from another perspective: consider +5V as it is 2.5V, GND as it is -2.5V and VREF as it is 0V.Both the amplifiers have an high pass input filter (@ around 41KHz) and a low pass filter (@ around 38KHz). The first stage is non inverting and the second is inverting.There is an additional high pass filter (C30+R17 and C31+R18) that basically blocks all the dc components at the comparators inputs. The comparators output are paralleled (these are open-drain outputs) and pulled up by R19. When the second stage output signal exceed ~VREF+28mV or is lower than ~VREF-29mV the comparator output goes low.To be clearer I've attached the schematic with a few comment. I have not performed a simulation but if you need it just ask.Hope this help.Best,0xfede

author: eerocketman
author_rank: Contributor
timestamp: April 16, 2018, 03:30:06 pm
content: Thank you so much for your response. I later found out that I couldnt see the familiar configurations. I redrew the circuit and rearranged some parts and it wasn't bad at all. Probably the lack of sleep getting to me!
Analyzing Response time of Comparator - Page 1
Forum section: electronics / beginners

author: kankanas
author_rank: Contributor
timestamp: July 07, 2020, 06:52:29 am
content: Hi,I am trying to find the response time of the LM311 Comparator. In the datasheet, the test condition is mentioned as "a 100-mV input step with 5-mV overdrive".I am a bit confused about the input of the ckt to be taken. I am attaching the schematic which I can think of now.I visited various sources online, but the inputs to be taken are not clear.Please correct me if my understanding is wrong.

author: kankanas
author_rank: Contributor
timestamp: July 07, 2020, 06:54:39 am
content: Below attached images..

author: mikerj
author_rank: Super Contributor
timestamp: July 07, 2020, 08:09:00 am
content: Set V5 to 95mv. This gives you a 100mV input swing with 5mV (i.e. 100-95) overdrive. Also it's not good practice to set rise and fall time to zero, it's an unrealistic value that can sometimes cause convergence problems in SPICE.

author: kankanas
author_rank: Contributor
timestamp: July 07, 2020, 09:10:46 am
content: Is this ok?

author: mikerj
author_rank: Super Contributor
timestamp: July 08, 2020, 11:26:25 am
content: Yes that looks ok.
Ancient transistor replacement? - Page 1
Forum section: electronics / beginners

author: Dave Wave
author_rank: Contributor
timestamp: March 16, 2012, 12:43:23 am
content: I am rebuilding the power supply on a small dc/dc converter. I want to replace the transistors.The part number from the mid-1980's was QF2014 (also QB2014).A search of the web and call to the local electronic supply house (who checked books from the 80's) turned up nothing.Anybody got a lead on where to check before I just replace them with generics?Thanks!-Dave

author: Rufus
author_rank: Super Contributor
timestamp: March 16, 2012, 01:06:46 am
content: Quote from: Dave Wave on March 16, 2012, 12:43:23 amFor your TI-59?. TI used to make TO92 plastic transistors by the million. They are probably internal part numbers.
Andonstar 301 HDMI question - Page 1
Forum section: electronics / beginners

author: Zuul
author_rank: Contributor
timestamp: May 25, 2019, 12:36:28 pm
content: Hello all!So I have this Andonstar 301 USB microscope that I find to be pretty great considering the price, BUT...(the setup is ADSM301 -> HDMI switch -> monitor) it seems that this only works if I plug in the HDMI cable after the microscope has "booted" up fully, otherwise I get nothing.I'm thinking about putting a small toggle switch directly somewhere on the cable going to pin 19 that's supposed to be "hot plug detect" so I don't mess up the connectors constantly plugging/unplugging.The obvious thing to do before I carve up a perfectly good miniHDMI - HDMI, that happens to be the only cable I currently own, is to ask : will this work?i.e wait for boot, pull the switch = profit. I have searched around the net but my google-fu is weak.Thank you in advance!EDIT: I guess I should add that the microscope at start up detects the cable, turns off the onboard screen very fast and then tries to output through HDMI but neither the monitor or the switch can keep up? I have tried it directly to monitor and same result.EDIT2: no that can't be it. The microscope detects the cable and then fails to output on HDMI? Because only way to get output is to wait for the camera to start, and then plug in

author: Zuul
author_rank: Contributor
timestamp: May 25, 2019, 01:52:01 pm
content: yeah this is more of a convenience thing than an actual deal-breaking fault...but you know...I wan't shit to work full autoAnd if it can be modified to the better then why not?my switch is model 4PET0402A ... 4in 2out. The switch doesn't change its mind while changing between inputs . The microscope just doesn't output if it sees HDMI at startup.Makes me think if there is a modification that can be done on the mainboard of the scope rather than cable to make it permanent fix...but this is too advanced for a saturday with a few beers in thecardio vascular system.
Andonstar AD407 opinions. - Page 1
Forum section: electronics / beginners

author: jerryk
author_rank: Regular Contributor
timestamp: December 05, 2020, 10:55:12 pm
content: I'm looking to get an Andonstar AD407 for smd soldering. As a significant side benefit I would like a better way to photograph magnified view of smd boards. Currently I do this through the eye piece of my AmScope SE400-Z. It's a difficult aiming process that is limited to very small areas on a board.I am curious how it is to solder under the Andonstar AD407. The optics look very close to the base leaving you little working room. Any opinions, experience, or advice along the digital microscope lines is greatly appreciated. Budget for me is around $200.Thanks - Jerry

author: MarkF
author_rank: Super Contributor
timestamp: December 05, 2020, 11:08:12 pm
content: This video may help.Also, I believe you can capture video and pictures to its SD card.There is also this one:
Android + Bluetooth + Arduino = Not Working - Page 1
Forum section: electronics / beginners

author: Brown
author_rank: Contributor
timestamp: January 08, 2014, 03:58:09 am
content: Hi, I got a HC-05 BT Module and an Android I tried thishttp://www.instructables.com/id/Andruino-A-Simple-2-Way-Bluetooth-based-Android-C/and it doesn't work. my phone connects with the module but the led wont turn off or on

author: Unknown
author_rank: Unknown
timestamp: January 08, 2014, 05:32:37 am
content: Something must be wrong then.Usual cause of things not working is wiring errors. Usually people say 10 times that it is correct and then on page 4 the OP comes back and says 'oops, wire in wrong hole lol' so check and recheck everything.

author: psycho0815
author_rank: Regular Contributor
timestamp: January 08, 2014, 11:44:20 am
content: Yeah check the wirering. Also, there are HC05 Modules out there that have 5V logic on the rx and tx lines (i know because i have one), so make sure yours is in fact 3.3V level. Otherwise loose the voltagedivider on the modules rx-pin. Also check the baud-rate. I think these things come with 9600-Baud, but that can be changed.Also try not powering the arduino from USB if youre doing that. Could be that the usb-uart chip is interfering. Not sure about that though, i only ever used those modules with SoftSerial on Arduino.

author: Brown
author_rank: Contributor
timestamp: January 09, 2014, 12:03:32 am
content: Ok so, I tried thishttp://www.instructables.com/id/Arduino-AND-Bluetooth-HC-05-Connecting-easily/?ALLSTEPSand it worked! Thanks
Android Viewer App for the Andonstar USB microscope - Page 1
Forum section: electronics / beginners

author: Carioca10
author_rank: Unknown
timestamp: February 26, 2016, 10:31:04 am
content: Greetings, everyone!I have watched some videos on youtube using an app called CameraFi for viewing the video output of the Andonstar on an Android device. I have downloaded CameraFi, but it seems too intrusive, needing some data of my Google account to work.Is there another alternative App?Many thanks in advance for any help.

author: michaeliv
author_rank: Frequent Contributor
timestamp: February 26, 2016, 06:33:12 pm
content: I had the same question as you, and I didnt like CameraFi because it adds a watermark to everything including the live view. I didn't manage to find anything that worked as good.This is an alternative:https://play.google.com/store/apps/details?id=com.serenegiant.usbwebcamera&hl=enYou can also try all these apps see which works for you:https://play.google.com/store/search?q=usb%20webcam&c=apps&hl=enI ended up modifying the APK so it wouldn't add the watermark for CameraFi. You can also try to install a firewall and block CameraFi from accessing the net.Also I see my version of CameraFi does not require google account info / contacts, etc ... Try to find an old apk that is less intrusive.