hybridfree/eevblog-posts huggingface dataset:
Pull up resistor of level translator  - Page 1
Forum section: electronics / beginners

author: Dot
author_rank: Contributor
timestamp: November 17, 2015, 02:40:25 pm
content: HiI am working with TXB0106 level translator (datasheet:http://www.ti.com/lit/ds/symlink/txb0106.pdf). While doing design, I came across page 12 in which an architecture of an I/O cell is displayed as shown below.On that page, it says that the typical output impedance during output transition is 50ohm, given that output high is in the range of 1.8V to 3.3V (the level I'm actually working with). I understand from this statement that during a high to low transition, or vice versa, the output can be typically modeled into a signal source with 50ohm resistor in series. On page 14, it says that if pull up resistor is connected on I/O, its value must be kept higher than 50 Kohm to ensure that it doesn't contend with the output driver of the IC.Why should it be higher than 50 Kohm? why can't I use a 4.7 Kohm R for example? I don't understand this bit about not contending with the output drivers, and I'm not sure how bad it would be if R is kept lower than 50K.

author: nfmax
author_rank: Super Contributor
timestamp: November 17, 2015, 02:55:49 pm
content: Following a transition, after the one-shot times out the low-impedance driver T1 .. T4 as appropriate is turned off, leaving the output driven only by the 'puny' inverter, through a 4k ohm resistor. If you use too small a value of external pull-up, the voltage divider between the 4k ohm resistor and the external pull-up will present an invalid logic level to the rest of the circuit. the output impedance of the level translator is only 50 ohmduring a transition(and for a short period afterwards).

author: Dot
author_rank: Contributor
timestamp: November 17, 2015, 06:33:24 pm
content: Thanks for the answer.One more question please:When input on B side goes from high to low, T4 will turn on providing a short-time connection to ground for the pulled up input on A side to sink current down to ground, thus reading low level. Can I assume that input impedance would equal to 50 ohm during this transition? and when T4 turns off again (one shot times out), how can pulled up input on A side sink current down to ground to keep reading low level? am I right in seeing that the second inverter would provide this path, sinking current from module's pin via a 4 Kohm impedance?

author: nfmax
author_rank: Super Contributor
timestamp: November 19, 2015, 09:20:22 pm
content: Yes, that's right: so long as the 4k ohm resistor from the inverter output can keep the A pin in the logic low state, both A and B sides will be low. But as soon as the A input goes above the high threshold, the positive feedback around the loop of 4 inverters will take both sides rapidly high. Any pull up (or pull down) resistor must be much larger than 4k ohm for the circuit to be stable in both states.
Pull-up resistors on 74HC series - Page 1
Forum section: electronics / beginners

author: ABCD
author_rank: Contributor
timestamp: May 21, 2011, 02:02:30 am
content: I have a 74HC112N, dual negative edge triggered JK flip flop with preset and clear. I want to set it to toggle mode, which I know how to do in terms of what the inputs need to be, but when it comes to wiring it up, I'm not sure how to configure the inputs. They can't be left floating, I know, and the datasheet says to tie unused inputs to either Vcc or GND. But it makes no mention of pullups. So, can I just wire J and K to Vcc, PRE and CLR to Vcc (they are active LOW) and be OK? (I'd tie all inputs for the second FF to Vcc I suppose.) My impression is that if I attached switches to J and K, I'd need to use pullups to keep the inputs at logical 1 (or pulldowns for logical 0) so that I don't short out the pins when I push the button.

author: tecman
author_rank: Frequent Contributor
timestamp: May 21, 2011, 02:39:00 am
content: You can tie any input hi or lo, as required, without any problem. Pull ups not required.paul

author: ABCD
author_rank: Contributor
timestamp: May 21, 2011, 02:54:10 am
content: Thanks, that's what I thought from reading the datasheet. If attached switches to inputs J and K, would a pullup then be needed? I am still a little unclear as to when they need to be used.

author: Zero999
author_rank: Super Contributor
timestamp: May 21, 2011, 08:39:19 am
content: I think you nedd to lead a bit more about what a pull-up/dwon resistor actually does so you can answer your own question.A CMOS gate has a high impedance (>10M) which can float at any voltage if not connected to either power supply rail.Now look at the internal structure of a typical CMOS gate.If VINis half way between VDDand the negative rail, both Qn and Qp will turn on causing a current to flow which would cause the output voltage to also flow between VDDand the negative rail. The result is your CMOS IC will use much more power than it's supposed to.When the gate is working properly and is static either Qn or Qp will be on, not both which should only happen when the input voltage is changing from high to low or vice versa.A pull-up/down resistor is only required when there's a chance a CMOS input will not be connected to either VDDor the negative rail.

author: ABCD
author_rank: Contributor
timestamp: May 21, 2011, 10:13:47 pm
content: Hero999-Thanks, I believe I have the concept down now.
PULL-UP RESISTORS ON OUTPUT PINS - Page 1
Forum section: electronics / beginners

author: neko efecktz
author_rank: Regular Contributor
timestamp: May 23, 2017, 04:41:03 am
content: Good morning Everybody.I have resolved my previous question posted yesterday.Just a few quick questions.What effect would it have, if any, if the output pins of a PIC namely PIC16F877A had 10K pull-up resistors.I just built a new board using different ports to my previous one, to make better use of port C particularly I want to use the I2C option of port C.Port C has terminals for I2C.I made provision on Ports B & C for pull-up resistor arrays and without thinking fitted an array to each.I was planning on usingPort A is analog input, already set up and working,Port B as Input, Port C for Output including I2C,Port D is set up for the 1602 LCDand Port E isnot committed.Is there any advantages in using Port B or Port C as input or output? which way would you go? Please keep it clean.I could suck out the array on Port C.Thank youBILL.

author: Fire Doger
author_rank: Regular Contributor
timestamp: May 23, 2017, 06:15:52 am
content: It doesn't have any effect that will make a difference at this level.Although usually development board doesn't have soldered pull resistors (or they have dip switch to enable them).You can just populate a female socket instead of the resistor array to be able to remove them on the fly.Don't think each port as an input or output, every time you will define what they will be depending on your needs (peripherals that you gonna use, etc.)

author: danadak
author_rank: Super Contributor
timestamp: May 23, 2017, 10:17:35 am
content: The 10K will add to power dissipation, a consideration if power isbattery derived.If the pin is tri stated on power up then of course the pullupforces a logic 1 at the pin, another consideration for externallogic driven by pin. That's a consideration if your pin drives aswitched high power load that should not be on when firststarting up until processor gains control over system.Regards, Dana.
Pull up/down resistors - Page 1
Forum section: electronics / beginners

author: blueskull
author_rank: Unknown
timestamp: May 14, 2015, 08:24:18 pm
content: Why do we need pull ups or pull downs for input pins? For STATIC operation, such as boot mode selection, can not we simply connect the pins directly to Vio or Gnd?For what I can think of is powering up a pin several ns before Vcc MAY cause latch up? But I always don't care about it, and it works all the time.

author: Neilm
author_rank: Super Contributor
timestamp: May 14, 2015, 08:56:55 pm
content: Quite often, the pins can have multiple functions and it could cause damage to the output stage if the pin was accidentally driven. You could end up with a dead short through the IC. The resistors will limit the current in this instance.

author: baoblackcoal
author_rank: Newbie
timestamp: May 15, 2015, 01:58:25 am
content: Sometimes need enough current.

author: TimFox
author_rank: Super Contributor
timestamp: May 15, 2015, 03:38:52 pm
content: Pull-up resistors:Original TTL and some other logic families were unhappy if the input voltage exceeded Vcc (for example, during turn-on) unless there was a current limit. A TTL output worked well, but a resistor was recommended for permanently pulled-up pins.Pull-down resistors: With TTL, the resistor must be relatively low due to the high input current at VIL.It is often considered good design to use a small pull-down resistor to ground, even when not needed, in order to allow in-circuit testing of the device with a controlled voltage or pulse to that pin.
Pull-ups and GTL2000 level shifter - Page 1
Forum section: electronics / beginners

author: agehall
author_rank: Frequent Contributor
timestamp: July 24, 2019, 07:35:52 am
content: I'm looking to build a FPGA<->PCMCIA interface using GTL2000 (https://www.nxp.com/docs/en/data-sheet/GTL2000.pdf) as a levelshifter inbetween. Now I'm trying to understand how to deal with the pull-up resistors on the high side (PCMCIA side using 5V).I have some fairly noobish questions here - I think I'm tripping myself up overthinking this...1) Some pins in the PCMCIA socket are pulled up via 10k+ resistors by the card. I assume I won't need any external resistors on those lines as called for by the GTL2000 datasheet?2) Am I correct in assuming that it is ok to use 10k+ pull-up resistors even though the GTL2000 datasheet points towards much smaller resistors? I guess I don't understand if the datasheets specifies a lower pull-up limit or not.3) PCMCIA standards calls for the address lines to be pulled to GND via 100k+ resistors inside the card. Should I put large (100k or so) external pull-ups on those lines or should I go for small (1k or so) resistors on those? I would assume I should put small pull-ups on these lines...
Pulling a line up for a while after power-up - Page 1
Forum section: electronics / beginners

author: andri
author_rank: Contributor
timestamp: April 16, 2011, 10:03:01 pm
content: Bit of background: I have a WRT160NL router that has a TTL serial, and I have built a small circuit that interfaces 1-Wire devices. Unfortunately, this circuit echoes everything the router transmits back to itself, which confuses the hell out of the bootloader when the router is restarting (it thinks someone pressed a key on the serial console and drops into rescue mode).Thus, I thought the obvious way to solve it would be to whip up something that pulls the RX line high for, say, 10-15 seconds after power-on giving time for the bootloader to do it's work and pass the control on to the Linux kernel; after that, the circuit may as well echo everything back again as it won't disturb anything critical anymore.However... I've tried figuring out how to build this kind of circuit and can't manage to do it. I have a feeling that it shouldn't be too difficult to do, with a resistor and a cap to provide the timing (no need to be super precise here) + a couple of transistors to actually do the pull-up.If anyone could lend a hand designing this, it'd be appreciated.(I'm more interested thehow, ie please don't slap a .png of a circuit that does it -- I want to learn!)Of course, I could give up and rebuild the whole damn circuit around an ATtiny13 MCU or something similar, and do the whole thing in software. It however feels... wrong to waste a MCU for something this mundane.

author: Psi
author_rank: Super Contributor
timestamp: April 16, 2011, 11:31:16 pm
content: Sounds like a good use for a 555 timer in one shot mode.ya can easy set that to 15seconds.

author: Zero999
author_rank: Super Contributor
timestamp: April 17, 2011, 10:58:39 am
content: If the input is a Schmitt trigger with a high imput impedance, you could connect a capacitor between the line and +V and a resistor from the line to 0V. Failing that, there are many options: 555 timer (as mentioned above), comparator, 74HC14 (or single Schmitt inverter), 74HC04 (or dual inverter) or even a couple of transistors.
pullup via single resistor vs mosfet - Page 1
Forum section: electronics / beginners

author: Moriambar
author_rank: Unknown
timestamp: November 11, 2021, 08:41:53 am
content: Hi,this question has been bothering me for ages.In an old book (read when I was even noobier), there was some trickery involving not tieing a pin up or down just via a pullup/down, but also to the drain of a fet.This way the pin logic value was controlled through the gate of the fet.Apart from the "inversion" of the value due to the fet, is there any other reason to do so, instead of straight pulling up/down via a resistor and then switch the signal directly from outside?Thanks

author: jpanhalt
author_rank: Super Contributor
timestamp: November 11, 2021, 10:08:09 am
content: One purpose is level shifting since the gate is insulated from the drain and source.
Pulse Counter for DC Voltage - Page 1
Forum section: electronics / beginners

author: Construction Solutions
author_rank: Newbie
timestamp: June 24, 2014, 08:56:04 pm
content: I think I need a pulse counter to measure flow from a hall effect water flow sensor. I am testing multiple units to find the best one for my application. In all testing I will be using 12V DC as the input voltage so I assume the output voltage will be 12V or less. Can anyone steer me in the right direction to find and purchase the correct pulse counter? This will likely be a one time use for me. Thanks.

author: Rerouter
author_rank: Super Contributor
timestamp: June 24, 2014, 08:59:07 pm
content: totalized flow or rate of flow? (totalised will require a unit with an option to disable the gate)

author: Construction Solutions
author_rank: Newbie
timestamp: June 24, 2014, 09:08:46 pm
content: Rate of flow.

author: IvoS
author_rank: Frequent Contributor
timestamp: June 25, 2014, 12:00:51 am
content: Don't forget that some water meters have actually 4 magnets inside. 2xsouth and 2x north pole. So you might have to divide all counts by 2.
Pulse Density Modulation, how do you interpret the bitstream? - Page 1
Forum section: electronics / beginners

author: Mattjd
author_rank: Regular Contributor
timestamp: January 20, 2019, 06:15:43 pm
content: Hi, i'm going through the projects at my Uni, each semester we must partake in one. One of the projects is creating a DAQ to read in MEMS microphone data. I'm reading up on pulse density modulation PDM, and I am confused on how to interpret the bitstream. I am reading the wikihereand under section description, the description is actually a little vague. I understand perfectly the equation they give but the wiki goes on to say"arunconsisting of all 1s would correspond to the maximum (positive) amplitude value, all 0s would correspond to the minimum (negative) amplitude value, and alternating 1s and 0s would correspond to a zero amplitude value. The continuous amplitude waveform is recovered by low-pass filtering the bipolar PDM bitstream."What do you define as arun?I'm very confused on how to decode the bitstream and obtain the amplitude of say the sine wave example they give here, a single period of a sine wave samples 100 timeswhich has the bitstream0101011011110111111111111111111111011111101101101010100100100000010000000000000000000001000010010101If i was reading this bitstream on a micro, are there so many values I am suppose wait and then that turns into my value? For example, therunwould be 010101 and those 6 bits correspond to some value of the sine wave amplitude? I did a simple test in matlab, using the equation given, I set A = 5, and used the bitstream from the example. I calculated a 1 by 100 array of consisting of -5 and 5, which i dont understand how this expresses the amplitude of the sine wave.

author: Benta
author_rank: Super Contributor
timestamp: January 20, 2019, 07:28:30 pm
content: A relatively simple approach that can be implemented in most microcontrollers is the "moving average filter" which will give you a low pass response as needed.

author: Mattjd
author_rank: Regular Contributor
timestamp: January 20, 2019, 07:37:06 pm
content: Quote from: Benta on January 20, 2019, 07:28:30 pmHow do you know how many points to do?Is the example incomplete?

author: Benta
author_rank: Super Contributor
timestamp: January 20, 2019, 08:06:53 pm
content: Quote from: Mattjd on January 20, 2019, 07:37:06 pmThat's a question of resolution. You'll need to look at the quality of your MEMS sensor signal. Perhaps an 8-bit window is enough? Or 10 bits? Or...Obviously processing time increases with each tap.

author: radioactive
author_rank: Regular Contributor
timestamp: January 20, 2019, 09:16:06 pm
content: Check this document out. It covers the details.https://www.analog.com/media/en/technical-documentation/application-notes/ee-350rev1.pdf
Pulse extender / delayed-off - Page 1
Forum section: electronics / beginners

author: gmichael225
author_rank: Contributor
timestamp: December 21, 2022, 12:50:38 pm
content: I’m hoping to put together a circuit that:- accepts a 30ms pulse of 24V @ 5A- activates a relay for a configurable time period between 0.1 and 5.0 seconds (in 100ms configurable increments with +/-20ms accuracy)where the circuit is powered entirely by the input pulse.I’m thinking of something like a cap or supercap being charged by the input pulse, then perhaps an R/C into a transistor to drive the relay - where the resistance component would be selected by DIP switches or similar - but I don’t expect this to achieve the requisite accuracy.I’ve looked at some monostable multivibrator chips but they seem to have excessive startup delay / won’t send a pulse when power is first applied - though there may be a way to get them to do so.How would you approach this?

author: JustMeHere
author_rank: Frequent Contributor
timestamp: December 21, 2022, 09:11:34 pm
content: I'd use batteries, a latching relay, and a dirt cheap micro like an Attiny4.

author: ledtester
author_rank: Super Contributor
timestamp: December 22, 2022, 08:31:04 am
content: This reminds me of the circuits in the book "Junkbots, Bugbots & Bots on Wheels" where solar powered robots were designed based on the idea of charging up a capacitor through a solar cell and releasing all of the stored energy only when the cap reached a certain voltage.Here's an example using a 1381 voltage supervisor for the trigger:http://solarbotics.net/library/circuits/se_t1_mse.htmlBesides "voltage supervisor" you can also search for "voltage detector/monitor/sequencer" to find similar kinds of devices.For a monostable multivibrator which triggers on power-up, perhaps a simple RC timer on the gate of a MOSFET like in this post:https://www.eevblog.com/forum/beginners/help-me-simplify-this-circuit/msg4591450/#msg4591450If Vin can be switched from 0V to Vcc (like by the voltage supervisor) and back to 0V the cap will discharge and be reset for the next round.
Pulse generator  - Page 1
Forum section: electronics / beginners

author: abhijitrkjr
author_rank: Newbie
timestamp: February 29, 2024, 12:04:28 am
content: Hi everyone,I need to build a high voltage pulse generator which could go upto few hundred volts on both polarity.Earlier I had used Willamette phvsw-005v pulser circuit. But now those are not available anymore because the company doesn't exist anymore. Does anybody knows a good alternative for that? I would also be happy to build a simple PCB if somebody has a design. I am a newbie in electronics so don't suggest me anything that's very complicated.
Pulse Peak Detector - Page 1
Forum section: electronics / beginners

author: jayesh
author_rank: Newbie
timestamp: February 22, 2018, 02:54:03 pm
content: Hi guys,can anybody suggest a pulse peak detector circuit for pulse widths in nano seconds.thanks.

author: danadak
author_rank: Super Contributor
timestamp: February 22, 2018, 03:03:51 pm
content: http://cds.linear.com/docs/en/design-note/dn185f.pdfhttps://www.edn.com/design/analog/4347624/High-speed-peak-detector-uses-ECL-comparatorRegards, Dana.

author: BrianHG
author_rank: Super Contributor
timestamp: February 22, 2018, 03:15:01 pm
content: You can use an MMBTH10 transistor, common emitter configuration, with your source signal fed to the base via a series input cap and a weak pull up resistor right on the base to VCC. On the collector, you will also have a pull-up to digital VCC and optional small cap in the pf range in parallel to GND. This simple switch amp will extract the peaks of your source, creating a digital IO so long as the source signal is 200mv or stronger.You will need to tune the input cap and pull-up resistor to tune the circuit's peak selectivity. The pullup resistor here will be around 100k and you may also want a smaller value pull-down resistor as well. Note that with this circuit, with no input, the output will always say that there is a continuous pulse unless you tune this pull-down resistor to keep the transistor off by default, but you loose some sensitivity. A stronger source signal above 200mv would mean no problem here.The output pull-up resistor should be around 2k to 10k depending on how wide/fat you want the output captured pulse to be.This amp is and active low output. When there is a peak, the output will be low.2SC5066-O,LF may be better than MMBTH10 for detecting pulses at 1ns or less as it is a 7GHz transistor, but still in the 25cent price range.Very strong pulses will be detected immediately, as the signal rises past the previous peak. Detecting exclusively after the peak has been reached, especially sub ns sized pulse is out of the range of such a simple circuit. Even danadak's posted suggestions is similar to my 1 transistor solution and wont wait until after the peak has been reached to be assured that the source has switched direction and the true peak for that pulse has been reached.You'll need a good scope to work on this circuit. Also, you'll need J-fet amplified low capacitance probes, or, you'll need extra transistors to buffer the signal typically in an emitter-follower configuration.

author: BrianHG
author_rank: Super Contributor
timestamp: February 22, 2018, 04:43:14 pm
content: Quote from: danadak on February 22, 2018, 03:03:51 pmThis component is no longer available. You can find a few if you only want to make a few of your project, but, do not go into production with this IC.
Pulse Power Supply = Switching Power Supply ?? - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: November 14, 2015, 04:27:36 pm
content: Is Pulse Power Supply only a different word connection for Switching Power Supply ?Or is it a different design?

author: dmills
author_rank: Super Contributor
timestamp: November 14, 2015, 07:20:26 pm
content: Usually a pulse power supply implies some sort of capacitor discharge thru a fast, high current switch and some sort of pulse forming network, think pulsed lasers, old school pulsed radar, that sort of thing.The charging supply might be a switcher, but that is not required.Pulse supplies are usually rated in joules per pulse, maximum PRF and pulse current rather then watts.Regards, Dan.

author: dom0
author_rank: Super Contributor
timestamp: November 14, 2015, 09:23:19 pm
content: Basically a high power pulse generator, just not with all the flexibility of a bench pulse gen.
Pulse stretch and delay - Page 1
Forum section: electronics / beginners

author: elki
author_rank: Regular Contributor
timestamp: March 19, 2024, 08:32:47 am
content: Hello! I am having a hard time understanding why this simple circuit based on 74HC123 does not work in practice, while the simulation results are as expected. I am getting exactly the same stretched pulse, but somehow, I am not succeeding in introducing a delay. Any ideas? Maybe there are some practical considerations to take into account?

author: Andree Henkel
author_rank: Regular Contributor
timestamp: March 19, 2024, 09:23:12 am
content: maybe problem is that the CxInputPins are basiscally floating - there is no DC connection to 5V or Gnd. Try connect a rather high value resistor, maybe 1MOhm to one of the rails at each of both Cx inputs.

author: Benta
author_rank: Super Contributor
timestamp: March 19, 2024, 08:29:33 pm
content: CX has to be grounded externally as well. And where are your decoupling caps?

author: elki
author_rank: Regular Contributor
timestamp: March 19, 2024, 08:35:56 pm
content: Thanks. Sorry for the newbie question: what do you mean exactly by CX grounding? How do you propose to modify the circuit?I have the decoupling caps on the power supply rail (not shown in the schematics, sorry).Quote from: Benta on March 19, 2024, 08:29:33 pm

author: Benta
author_rank: Super Contributor
timestamp: March 19, 2024, 08:41:03 pm
content: Quote from: elki on March 19, 2024, 08:35:56 pmJust connect the CX pins to ground (or 0 V, if you like that term better).
Pulse Stretching - Page 1
Forum section: electronics / beginners

author: djdc13
author_rank: Newbie
timestamp: February 21, 2020, 07:06:12 am
content: I want to build a PC fan controller for 3 and 4 pin fans (universal). The 4 pin fans are simple as it is just a PWM signal I am generating from Arduino (after changing the PWM frequency on the pins). Running the 3 pin fans with a PWM signal is also working. Sensing the speed of the 3 pin fans with the Arduino is also working but I can not sense the speed of the 3 pin and power them at the same time. The tach signal from the 3 pin fan is powered by the fan power so if you provide a PWM signal as power the tach signal gets chopped and reads incorrectly. I understand I need to utilise pulse stretching so that I can read the RPM on the longer pulses whilst the tach signal is not being chopped but this is what I am stuck with. I do not know how to code the Arduino to do pulse stretching and I do not know if there is an analogue way using just components and no microcontroller.It would be super awesome if anyone could give me an idea. If this pulse stretching could be sorted then I could make a fan controller with separate channels for each fan, I could have ports for 4 and for 3 pin, I could read all the RPM and I have also rewired all my fan LEDs through a constant current driver so could use another PWM channel to control the LED lighting too all in one package. If I cant figure it out I can either power them with a linear voltage (which I didnt want to do due to efficiency and easier fan stalling) or use only 4 pin fans but that would require changing fans and being defeated lol.

author: ggchab
author_rank: Frequent Contributor
timestamp: February 21, 2020, 08:23:57 am
content: Some ideas from my own experiences:- do you control the GND pin with your PWM signal ? You should try the +12V- some fans do not work very well with pwm. Adding a capacitor between GND and +12V helps- for some fans, the "tach" pin is not a "tach" signal but just a logical level that indicates if the fan is running or not

author: djdc13
author_rank: Newbie
timestamp: February 21, 2020, 09:40:31 pm
content: Thanks for the tip. I am using a low side P-MOSFET switch to control the fan with the PWM signal so yes I am switching the ground. This is to be able to switch without having to have a higher voltage then the switch voltage as I want to use the full 12V of the PSU. Also the 3rd wire in all the fans I have are definitely tach wires as I do get an RPM output on the screen or serial monitor but as the PWM duty is adjusted the readout suddenly goes unstable and reads garbage. I do use a filter capacitor and this helps a little but does not solve the chopping of the tach signal.
Pulsed Output to Continuous conversion. - Page 1
Forum section: electronics / beginners

author: sk614
author_rank: Contributor
timestamp: June 01, 2016, 05:51:37 pm
content: Is it possible to convert a pulsed output voltage to a continuous output voltage? Specifically, I am looking at this device P2110 RF Harvester Receiver.http://www.powercastco.com/test566alpha/wp-content/uploads/2009/03/p2110-datasheet-rev-b.pdf. On page 3 Vout is Pulsed...are there ways to convert that to continuous?Would using a PWM to analog such as thishttp://www.ti.com.cn/cn/lit/an/spraa88a/spraa88a.pdfwork?Edit:

author: danadak
author_rank: Super Contributor
timestamp: June 01, 2016, 07:01:59 pm
content: Thge TI ap note is an excellent way of handling this. Basically you arebuilding a LPF, Integrator, and that will convert to pulse to avg DC,with some ripple as discussed in ap note.Note this is for a periodic waveform. If waveform aperiodic burst youwill need to allow for settling time in LPF design as another consideration.Depending on waveform this could force you into an active design.What is the range of pulse width you are getting and desired resolutionand accuracy you want for the DC out ?Another ap note TI did attached.Regards, Dana.

author: sk614
author_rank: Contributor
timestamp: June 02, 2016, 02:34:34 pm
content: Thanks! I am planning ahead to see if it is possible to do. My plan is to convert the pulsed signal of the P2110 RF Receiver. Question: Since I can only get the average DC of the pulse, what can I do to boost the signal up to peak voltage of the pulse?

author: danadak
author_rank: Super Contributor
timestamp: June 02, 2016, 03:49:17 pm
content: Then consider peak detection circuithttp://ww1.microchip.com/downloads/en/AppNotes/01353A.pdfhttp://cds.linear.com/docs/en/design-note/dn61f.pdfhttps://www.maximintegrated.com/en/app-notes/index.mvp/id/1163http://www.intersil.com/content/dam/Intersil/documents/an10/an1097.pdfhttps://www.intersil.com/content/dam/Intersil/documents/an51/an517.pdfhttp://www.cypress.com/file/113046/downloadhttp://www.cypress.com/file/134261/downloadRegards, Dana.

author: rfeecs
author_rank: Frequent Contributor
timestamp: June 02, 2016, 04:55:33 pm
content: I don't see that the output is necessarily pulsed. According to the description:QuoteIt sounds like as long as you have enough voltage available in the storage capacitor, the output will be turned on. The device already does energy storage and boosts the voltage. I don't see that you need anything else. In fact, adding additional circuitry would just waste energy.
Pulse/Patern gen vs arb wave gen - Page 1
Forum section: electronics / beginners

author: fonograph
author_rank: Frequent Contributor
timestamp: September 24, 2017, 09:55:31 pm
content: What is the difference between arbitrary wavegorm generator and pulse/patern generator? When looking at all the products Keysight makes,they have these two units descibed as patern/pulse generator,what are these things? What are they used for? How are they different from your normal arb gen?I specificaly have Keysight 81150A - 81160A in mind

author: alm
author_rank: Super Contributor
timestamp: September 24, 2017, 10:09:51 pm
content: A pulse/pattern generator is generally designed for digital systems: You set the high and the low level, and the signal will vary between those levels at intervals and rates that you specify. Signals will generally be some sort of pulse train. In the case of a pattern generator, this can be a complicated signal (e.g. simulating a digital signal from a sensor). An arbitrary waveform generator is more aimed at analog signals: You specify the voltage level the signal should have at every point in time. This can lead to all kinds of analog signals like sinusoidal signals or ramps. This flexibility will limit the performance: the edge rates and memory depth will generally be lower than a pulse generator at a similar price point.The Keysight 811x0A series confuses matters by an analog output, in addition to the pulse output.
Pulse/Signal Delay circuit - Flip-Flop - Page 1
Forum section: electronics / beginners

author: rentner
author_rank: Regular Contributor
timestamp: October 07, 2014, 08:48:55 pm
content: Let me explain this:I have one input pin on a circuit which can detect 2 things: A rapidly rising OR a rapidly falling Voltage - in short a Pulse.Rising Pulse will switch something on and a falling Pulse will switch something off.Sometimes a falling Pulse is generated directly after the rising voltage pulse, which would turn the circuit on and off emidiately in matter of nanosecounds. (Depending on the Transistors speed of course)The circuit is just a Flip-Flop which needs to turn on, if I apply a quickly rising voltage through a capacitor to the Base of Transistor 1. If the Voltage is high and a Pulse with falling voltage gets through, the Flip-Flop inverts.However I want to slow the Flip-Flop down, to just accept a pulse every 100-150ns, but I don't want any delay on the output. The only difference to a discrete Flip-Flop is, that I added a Cap to the base of Transistor 2 to basically eliminate the saturation, just to get a much faster Flip-Flop.Well, how do I realise that? I got absolutely no Idea.EDIT:Oh, not neccesary anymore - found out another way. saves me some components.
Pulseview (sigrok) SPI SD card decoder - Page 1
Forum section: electronics / beginners

author: fabiodl
author_rank: Frequent Contributor
timestamp: December 30, 2020, 02:53:13 pm
content: I am analyzing an SD (SPI mode) traffic, where the master is done through bitbanging.Sigrok SD analyzer recognizes the first CMD17 and its payload, but not the traffic from the second CMD17 onward.Is there an error in my transactions or is it a sigrok decoder error?I attach the sigrok session file.For reference, here are the Pulseview infoVersions, libraries and features:PulseView 0.5.0-git-4ef2738Qt 5.12.8glibmm 2.64.2Boost 1_71libsigrok 0.6.0-git-025bd56f/4:0:0 (rt: 0.6.0-git-025bd56f/4:0:0)- glib 2.64.2 (rt: 2.64.3/6403:3)- libzip 1.5.1- libserialport 0.1.1/1:0:1 (rt: 0.1.1/1:0:1)- libusb-1.0 1.0.23.11397 API 0x01000107- Host x86_64-pc-linux-gnu, little-endian- SCPI backends TCP, RPC, serial, USBTMClibsigrokdecode 0.6.0-git-9dc13f0/4:0:0 (rt: 0.6.0-git-9dc13f0/4:0:0)- glib 2.64.2 (rt: 2.64.3/6403:3)- Python 3.8.2 / 0x30802f0 (API 1013, ABI 3)- Host x86_64-pc-linux-gnu, little-endian

author: rstofer
author_rank: Super Contributor
timestamp: December 31, 2020, 03:37:13 am
content: Are you handling SS' properly? Every transaction needs to be framed by SS'.http://www.dejazzer.com/ee379/lecture_notes/lec12_sd_card.pdf

author: fabiodl
author_rank: Frequent Contributor
timestamp: December 31, 2020, 04:23:38 am
content: I believe so. I had a doubt on whether cs should be released before reading the bulk data, but according tohttps://electronics.stackexchange.com/questions/307214/sd-card-spi-interface-issue-read-operation-returns-0x3f-0xff-instead-of-0x7f-0it seems I am doing it correctly

author: rstofer
author_rank: Super Contributor
timestamp: December 31, 2020, 05:33:22 am
content: OK, you need to leave SS' low throughout the entire transaction of CMD, POLL, READ and then raise SS'That makes sense because in other SPI transactions, raising SS' terminates the process, whatever it was.One problem with SPI is to make certain the last byte has been handled before raising SS'. This is more of a problem with hardware SPI. It can be that the last byte has been passed to the hardware SPI but the code can't immediately raise SS' one instruction later because that byte hasn't transferred yet. You would test the SPI gadget to see that the last byte has been transmitted before raiding SS'

author: fabiodl
author_rank: Frequent Contributor
timestamp: January 03, 2021, 02:19:51 pm
content: I am doing anything in "hw" (fpga) and the CS is raised after the reading the two crc bytes.
Pulseview + kingst la1010 - Page 1
Forum section: electronics / beginners

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: May 17, 2022, 11:35:15 pm
content: A friend lent me since I needed a logic analyzer with at least 12 channels, for that reason he lent me a kingst la1010, but I can't get pulseview to detect it, is there a way or not?in spanishUn amigo me presto ya que yo precisaba un analizador logico de minimo 12 canales, por ese motivo me presto un kingst la1010, pero no consigo que pulseview ,me lo detecte, hay alguna manera o no se puede??

author: ledtester
author_rank: Super Contributor
timestamp: May 18, 2022, 02:20:51 am
content: Kingst has their own software:http://www.qdkingst.com/en/downloadYou could try that first just to see if it recognizes your device.This review video:SDG #063 An affordable 16 Channel Analyser - Kingst LA1010https://youtu.be/jsMXPMs4-0cappears to be using the Kingst program.

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: May 18, 2022, 12:53:59 pm
content: if the LA1010 program detects it for me, I wanted to use pulseview, because I am already adapted to it, but well, I have no other choice, since mine is the generic Chinese eight-channel one.in spanishsi el programa de LA1010 me lo detecta, queria usar pulseview, porque ya estoy adaptado a este, pero bueno, no me queda otra, ya que el mio es el generico de ocho canales chino.

author: voltsandjolts
author_rank: Unknown
timestamp: May 18, 2022, 01:26:24 pm
content: The LA1010 is not supported in Pulseview.LA1016 is the cheapest Kingst analyser supported in Pulseview.It is confusing that it mentions it in source code but does not support it.It was an odd decision by Gerhard to do that - looking to support in future I guess.https://github.com/sigrokproject/libsigrok/commit/cafcfe6374241f4e057802f6e496b469d0de67da

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: May 18, 2022, 01:44:35 pm
content: Quote from: voltsandjolts on May 18, 2022, 01:26:24 pmThank you, I will take it into account if I were to buy one of these, I would choose the LA1016 model.

author: Naguissa
author_rank: Regular Contributor
timestamp: March 15, 2023, 11:07:38 pm
content: Old post, but just accomplished to use Kingst LA1010 with Pulseview, on Linux (root) and Windows (you need to also install KingstVIS).I write down spanish instructions. I post Google translate here; you can ask me any question here.https://www-foroelectro-net.translate.goog/herramientas-f27/analizadores-logicos-kingst-la-xxxx-y-sigrok-pulse-t474.html?_x_tr_sl=es&_x_tr_tl=en&_x_tr_hl=es&_x_tr_pto=wappCheers!
Pulsing DC voltage needs to be smoothed out with capacitors.   - Page 1
Forum section: electronics / beginners

author: WindyMarcus
author_rank: Newbie
timestamp: March 21, 2024, 05:48:32 pm
content: I have designed a wind turbine generator that creates AC voltage. The frequency and voltage vary as the wind speed changes. I use a full wave bridge rectifier to convert the voltage to DC. However this DC voltage is pulsing or not clean. (Sorry I know very little about this so forgive my incorrect use of terms.) Anyway, I understand I can use the correct capacitor to smooth a constant DC voltage and amperage. In my case the voltage and amperage is constantly changing. So I wonder is there a way to use multiple capacitors to smooth the mess and get a clean steady DC flow?NOTES: The frequency on the AC ranges from zero to 50 kHz. After rectifying the DC voltage ranges from zero to 50. The amperage ranges from zero to 6.Is there a way to sense voltage ranges such as 10-15 volts at .8 - 1.1 amp (for example) then use one capacitor to smooth that? Next sense the next level of voltage and switch to another capacitor? Is this the hard way to do it? I hope there is an easier way.Since I am trying to create electricity I want to avoid losses as much as possible.Would this solve the matter for me? If I run the DC voltage into a controller/charger (designed for this purpose to charge batteries) would it deal with the pulsing and charge a battery bank efficiently?

author: artag
author_rank: Super Contributor
timestamp: March 21, 2024, 10:27:53 pm
content: You don't need to use the exact capacitor calculated for any particular load. The result of using too large a capacitor is that it will stay charged longer and will take more current when it charges - so you can calculate for the worst-case (highest current load) and use that for everything.
Purchased a LeCroy 9424 Quad 350 MHz Oscilloscope 100Ms/s 10Gs/s and need advice - Page 1
Forum section: electronics / beginners

author: ExodusEffects
author_rank: Contributor
timestamp: August 27, 2018, 10:24:04 pm
content: Thank you for taking the time to read this and hopefully this is a simple common issue ( if it’s not no worries cause I could just use three channels ) but the scope works perfectly besides channel 3 will not auto detect the 10MHz signal from the probe.That package has literally just shipped so I am a little premature in my posting. I was rolling the dice on the fact this is common and maybe people could help me understand what I may be in for trying to fix channel 3.This is only my second scope, two weeks ago I picked up a new Rigol DS1054Z and hacked it to 100MHz. Everything else was already unlocked because of the promo needless to say. Is this going to be a good combo of scopes to learn with? I know Lecroy makes great scopes and to be honest I mostly just do audio right now. However I’m branching out now into logic and I’m sure I’ll just keep branching out and spreading within electronics.

author: Atom
author_rank: Regular Contributor
timestamp: August 28, 2018, 07:34:46 pm
content: well that lecroy is a beastif they would give me one for free i surely woudn't refuse it. by the way i'm the least qualified person to suggest a repair but i think in those models a common failures are the psu modules , now , again i'm a student and know next to nothing but maybe thats the problem, i'd say open it up and take a look at the frontend and the circuitry than starto to check for rail voltages .....maybe you ll spot some evident failure, hope you can find the fault.how much did you pay for it ?
Purchase Kapton polyimide film by DuPont for a competitive price  - Page 1
Forum section: electronics / beginners

author: zillah
author_rank: Contributor
timestamp: September 10, 2018, 09:26:13 am
content: https://www.eevblog.com/forum/beginners/polyimide-(kapton)-tape-is-it-that-expensive/Hi AllI have been using knockoff polyimide film that I had bought it from eBay and I want to buy genuineKapton polyimide film by DuPontto feel the difference.On amazon can I find a competitive price ?Thanks

author: GadgetBoy
author_rank: Regular Contributor
timestamp: September 10, 2018, 09:29:42 am
content: Are you based in Canada or the states? My previous employer, RP electronics carried an offbrand polyamide that was basically indistinguishable from the 3m stuff (which we used to carry, but nobody would buy it because the other stuff was just as good and about 1/3d the price).Sent from my ONEPLUS A3000 using Tapatalk

author: zillah
author_rank: Contributor
timestamp: September 10, 2018, 09:33:20 am
content: QuoteI am based in Australia and I don't mind to buy from amazon USAQuoteI seeQuoteIs t made by 3M or DuPont ?QuoteOhh I see

author: GadgetBoy
author_rank: Regular Contributor
timestamp: September 10, 2018, 09:37:53 am
content: DuPont made the film, but 3M made the adhesive. It was branded 3M, though.Sent from my ONEPLUS A3000 using Tapatalk

author: zillah
author_rank: Contributor
timestamp: September 10, 2018, 09:49:38 am
content: QuoteThx for clarification

author: t1d
author_rank: Super Contributor
timestamp: September 10, 2018, 04:46:21 pm
content: Quote from: GadgetBoy on September 10, 2018, 09:29:42 amPlease post product make and model. Thanks.EDIT: Is this it?https://www.rpelectronics.com/Common/System/Search.aspx?SearchText=kapton&SearchType=1

author: GadgetBoy
author_rank: Regular Contributor
timestamp: September 10, 2018, 05:40:52 pm
content: https://www.rpelectronics.com/Common/System/Search.aspx?SearchText=Polyimide&SearchType=1Sent from my ONEPLUS A3000 using Tapatalk
Purchased a Hakko fx950 - can't get it working - Page 1
Forum section: electronics / beginners

author: rfleming
author_rank: Regular Contributor
timestamp: December 23, 2020, 12:30:30 am
content: Hi All,I recently purchased 2xHakko fx950's for work and have been unable to to get them to operate yet. After assembly of both I installed the tips I got with the purchase from Oritech and both irons show the "Sensor error", you can see what I refer to in the below manual.https://www.srt.co.th/download/MANUAL/FX-950_Manual%20(En).pdfI have come to the conclusion that either my colleague and I are peanuts and don't know how to follow 3 steps in a manual, or we purchased the wrong tips.Could there be anything we have done wrong in a general assembly from others that may have ran into something similar?Cheers,Ryan.

author: rfleming
author_rank: Regular Contributor
timestamp: December 23, 2020, 12:34:38 am
content: Annnnnd we were peanuts...Simply didn't push the tips in hard enough...

author: Kerlin
author_rank: Regular Contributor
timestamp: December 24, 2020, 02:53:40 am
content: I wouldn't push the tip in too hard I found those things to be very fragile, thin and flimsy.
Pure opamp integrator definition - Page 1
Forum section: electronics / beginners

author: zzlong94
author_rank: Contributor
timestamp: November 22, 2017, 05:49:38 pm
content: The definition of pure opamp integrator is also known as ideal integrator?which means the integrator would not need a feedback resistor Rf to connect parallel with feedback capacitor, Cf?

author: rstofer
author_rank: Super Contributor
timestamp: November 22, 2017, 06:46:16 pm
content: Correct, there is no resistor in the feedback path.I use the integrator circuit for analog computing. The input resistor is 1Mohm and the timing capacitor is 1ufd so the time constant is 1 second. That turns out to be 'real time' for the problems I play with.

author: Zero999
author_rank: Super Contributor
timestamp: November 22, 2017, 06:53:57 pm
content: In an op-amp integrator, the capacitor is charged/discharged, with a constant current, which is directly proportional to the input voltage. The advantage over an op-amp integrator, to a plain old RC circuit, is the current flowing in/out of the capacitor is independent of the voltage on the capacitor. Of course this assumes that the op-amp's output is not saturated.
Purpose of 0.5 ohm resistor between input and output on -ve rail of SPS? - Page 1
Forum section: electronics / beginners

author: synoptica
author_rank: Contributor
timestamp: September 24, 2018, 01:33:08 pm
content: Hi all,I'm building up a proof-of-concept circuit using several small switching buck converters like these:https://www.aliexpress.com/store/product/Li-lion-Lithium-Battery-Charger-Module-5V-32V-to-0-8V-30V-5A-LED-Driver-Step/1818738_32829346770.htmlOn the negative rail, there is a 0.5 ohm resistor that separates the input from the output. Is this most likely a current shunt, or something else?I'd like to make a simple PCB to house all the components, but this would be easier with a common negative rail.Any input appreciated!

author: brabus
author_rank: Frequent Contributor
timestamp: September 24, 2018, 02:13:24 pm
content: Yep it is a current shunt. The whole idea behind it is that the battery ground and the supplied circuit ground will remain separate.Measuring the charging current with a low-side resistor is therefore easy and practical (you just measure its voltage referenced to ground).

author: synoptica
author_rank: Contributor
timestamp: September 25, 2018, 09:40:55 am
content: Cool. I didn't realise that 2-sided PCBs were barely more expensive ones so shouldn't be the problem I thought it would be anyway - but good to know I had the right idea anyway - thanks!

author: Zero999
author_rank: Super Contributor
timestamp: September 25, 2018, 03:23:53 pm
content: Yes, having the current sense resistor on the negative side is extremely common, because quite often op-amps and comparators work with both inputs at the negative rail, but not at the positive rail. Linked below is an LED driver kit, which uses the LM393 comparator and has the sense resistor on the negative side of the LED chain, because the LM393 won't work with its inputs at the positive rail.https://www.velleman.eu/downloads/0/illustrated/illustrated_assembly_manual_k8071_rev1.pdf