All Questions
199,999
questions
2
votes
1
answer
1k
views
Altium VersionControl_RevNumber special string
I have encountered a rather strange problem in Altium Designer 17.1. I am using the special strings VersionControl_RevNumber and VersionControl_ProjFolderRevNumber to keep track of our PCB Revisions ...
- 1,065
2
votes
1
answer
671
views
Identifying SMD Resistor with a code that contains a colon
What are the blue components seemingly labeled "69:1" in the attached image?
There is reason to believe that they are resistors, but of what value?
I thought perhaps the ":" is a "00" written on top ...
- 21
0
votes
1
answer
326
views
Specifying relay for breaking injection molding control circuit
I have an application which requires me to break a 24v signal running with low current (60ma being the absolute max). The signal stays on allowing a large hydraulic motor to close a mold with great ...
- 1
1
vote
2
answers
3k
views
12v to 18v for tools from car battery [closed]
I've looked at DC-DC converters for 12v to 18v and they usually have low amperage ratings. One for $50 can use 15A with 25A spikes. But cordless tools can pull much more than that, especially the saws ...
- 141
2
votes
1
answer
349
views
What will be the current of a 24 V ATX power supply?
I have an ATX power supply with a +12 V 8 A line and a -12 V 0.8 A line. I assume if I used the -12 V as ground to provide 24 V, then the maximum current provided by the 24 V line would be 0.8 A?
- 251
0
votes
0
answers
182
views
drilling a heatsink for a hot silicon diode?
I had to adjust a CC/CV charger by 0.5-0.8 volts. The charger is rated at 3.5 Amps 58.8V, and I have some 50-100V diodes rated at 5A ( 6A10 MIC ).
The diode gets to about 100'C which is a bit on the ...
- 939
0
votes
1
answer
122
views
2 Phase zero time switch
I'm trying to build an instant or zero 2 pole switch (DC current). Basically what I'm trying to accomplish is that when the switch is powered off, the lines are connected like shown in the first ...
0
votes
2
answers
79
views
Motor of what type should I choose?
I want to build something that behaves like a regular magnetic compass, but using this electronic compass and some motor what will rotate the arrow pointing to the north.
So I think the motor must ...
- 111
1
vote
2
answers
760
views
Limit MC-60 controller output
I am building a CNC engraver/Router. I have a Chinese 12-48 VDC, 400 W PM spindle. The spindle speed is from 3000 RPM at 12 V input to 12000 RPM at 48 V. I want to drive the spindle with a MC-60 ...
- 11
0
votes
1
answer
489
views
LTspice gain enhancement sallen and key highpass simulation
I have been trying to simulated a filter and amplification circuit. In one of the stages I am using a LP Sallen and Key circuit and another I am using a HP Sallen and Key circuit. I can successfully ...
- 1
50
votes
4
answers
14k
views
Loud pop noise while plugging to a headphones jack
I have a Panasonic RX-ES29 boombox with a type C plug (ungrounded). I sometimes hear a relatively loud snap/pop sound in the right speaker of my headphones while I completely plug them into the ...
- 563
2
votes
4
answers
784
views
Can an electronic device continuously sweep the voltage?
Modern power supplies can sweep the potential in a given range with a specific rate. I am curious if the electronic devices can continuously sweep the voltage (in a perfect sense) or it is just step-...
- 139
0
votes
0
answers
480
views
What is the charging current specification of a BMS?
I'm planning on using this BMS: https://www.aliexpress.com/item/3S-11-1V-25A-Li-ion-Lithium-18650-BMS-PCM-battery-protection-board-bms-pcm-with/32816991614.html
And 3 Samsung 18650 cells in series: ...
- 21
0
votes
0
answers
133
views
Using Transistor to dump excessive voltage?
I'm way over my head with this and need a poke in the right direction.
I'm building a small hobby LiPo charger (I'm aware of the risks with a LiPo battery packs regarding usage, charging and ...
- 183
0
votes
2
answers
3k
views
555 circuit for moisture sensor
I have built a grain moisture sensor using a 555 timer and an arduino,
as shown in the figure:
.
The sensor is composed of a two parallel aluminum plates (as in a capacitor):
The output of this ...
- 1
0
votes
2
answers
3k
views
How long will an 6000 mAh battery pack power a 12v 60W amp for?
I could use some help calculating how long my battery will last. I’ve tried multiple online calculators.
Speakers: Peavey Monitors with 10 inch woofer, 1.4 tweeter ~ 101 max SPL
Amp: Pyle PFA200 60-...
- 111
5
votes
2
answers
753
views
Frequency response of dual vs single op amp: OPA2890 vs OPA890
I am looking for an op amp to use as a unity gain buffer with a disable feature. The OPAx890 looks like a good candidate because it is unity gain stable.
I have noticed that some op amps labeled as ...
- 1,098
1
vote
1
answer
699
views
Gerber Setup Options
I have almost finished my PCB design and preparing to make Gerber files. I have some doubts related to Gerber Setup Options of Altium Designer 16.1.My first quesiton about Files->Fabrication Ouputs->...
- 363
4
votes
2
answers
2k
views
Device/circuit for high current, short pulse discharge?
I'm tasked with replacing a relay with a semiconductor switch in a high voltage, high current, short pulse duration application (all relative, I concede). Basically I'm charging a capacitor up to ~...
- 2,516
1
vote
0
answers
260
views
Closed-loop systems - discrepancy between Simulink and Arduino
I am trying to figure out how to reproduce closed-loop systems in Arduino that were designed initially designed in Simulink.
Take the following closed-loop system with unity feedback and gain:
Where ...
- 41
11
votes
4
answers
3k
views
Pulse withstanding capability of standard resistors
How much pulse power does a standard (i. e. not further specified) resistor withstand?
Consider for example a MOSFET and a 33R resistor that is connected to its gate. If the switching voltage would ...
- 313
2
votes
1
answer
221
views
Do I have to use a MAX485 chip in front of an ATXMega microcontroller?
I'm doing a project which involves receiving DMX 512 information on an ATXmegaA3u microcontroller. I've successfully implemented the protocol using the onboard USART of the microcontroller. Basically, ...
- 129
2
votes
1
answer
3k
views
current source pull up [closed]
After searching, I was unable to find a clear answer so.....
Looking at datasheets for different microcontrollers and other chipsets, a pull-up or pull-down current is often mentioned instead of a ...
- 41
3
votes
1
answer
414
views
Determining speed of turbocharger via sound?
There are inductive sensors which can be retrofitted to turbochargers to measure their speed, like this:
Examples can be seen here.
Installation requires some careful and precise drilling and ...
- 3,873
-4
votes
3
answers
184
views
Back-EMF related question
If a circular dipolar magnet is set to roll down an incline through an array of coils set out as found in a bicycle dynamo – one above and one below per set, but linearly along the incline. Arranged ...
- 1
1
vote
1
answer
702
views
Line impedance in 4 layer PCB
i have a question..
I have a 4 layer PCB where top layer is a track layer, 1st middle layer is a GND plane, 2rd middle layer is a Vcc plane and bottom layer is a trace layer.
The layer stak table ...
3
votes
2
answers
2k
views
Detecting JTAG pinout
I want identify JTAG pinout on the target board, using the JTAGenum tool.
I have read the JTAGenum code, and want to clarify a few point about user configuration. JTAGenum can identify 4 mandatory ...
- 359
1
vote
1
answer
178
views
What's this sensor called? Found it in my AC unit
It's a 2 wire sensor I found in my central home air-conditioning unit. Any ideas what it's called? Wasn't able to find a part number on it.
Is there a test I can do to find out, using a multimeter?
- 125
1
vote
3
answers
4k
views
What could happen if a lightning strikes a car with a battery connected to the chassis ?
I was wondering today what could possibly happen if a lightning strikes my van where I have a 12V battery negative connected to the chassis. Could that destroy the battery or start a fire?
In order ...
- 239
2
votes
2
answers
111
views
Battery Powered LED Light Delay
I’ve created an airgun bell target and attached an led light to it which lights up for just a second when the target is hit. However, I was wondering if there was an easy way to make the light stay ...
- 21
1
vote
3
answers
914
views
How can these GPS/GPRS bike tracking locks be so power saving?
I am really puzzled by how these GPS/GPRS, solar-powered bicycle locks seem to be running on very little power. They are fitted with a tiny solar panel.
As you may know, these locks are popular these ...
- 337
0
votes
2
answers
406
views
Envelope detector and DC voltage
I am currently working in the simulation of a physics project. One of the detectors inputs a voltage V1:
V1(t)= D+Acos(wt)
and tries to extract the amplitude. I read that a simple Envelope detector ...
- 101
0
votes
1
answer
56
views
How to set a value of JESD
I'm trying to connect an ADC with an FPGA via JESD, but I'm not able to set a relevant parameter on in. Here is the link of the datasheet, where in the page 92 there are several parameters. In order ...
- 47
3
votes
1
answer
192
views
Help identifying this sensor
I would like to know if this is a sensor and the name of it if it is possible. I post two pictures, sorry about bad quality of them.
In my opinion it works sending different signal if something is ...
- 155
1
vote
2
answers
320
views
How does CLKOUT works on the LTC2323-12 ADC on "High-speed" speed mode?
http://www.farnell.com/datasheets/1833817.pdf
I was assigned a task where I have to connect an LTC2323-12 ADC (analogic to digital converter) to an FPGA.
Reading the LTC2323-12 datasheet seemingly ...
- 225
0
votes
1
answer
86
views
Vacuum robot sensor
Some one knows what kind of sensor is this and how it works? Is from a vacuum robot. I guess to check something on floor. I would like to connect it to Arduino.
- 155
10
votes
3
answers
4k
views
Is a valid USB VID/PID necessary for strictly embedded use of the Bus?
So the system of USB VID/PIDs as far as I understand it is to avoid conflicts between devices and the USB-IF is handling the distribution of these IDs and wants a fee if you need a VID and a ...
- 1,378
0
votes
1
answer
19k
views
reversing direction of single phase motor
I would like to change the direction of rotation of a single phase 240v motor.
I understand to do this I need to reverse the polarity of the start coil - but I'm not sure what wires are the start ...
- 19
-1
votes
2
answers
982
views
Purpose of low voltage pins on TV power switch
I am building an arcade machine, using a CRT television. I am wishing to replace the television's front panel power switch with a toggle switch on the outside of the cabinet but am concerned by two ...
- 147
-4
votes
2
answers
354
views
Hi Can we have delay timer with one Shot ON/OFF?
Need a Timer circuit like, for 20 sec it should be on then completely off. generally RC timer gets off gradually so the buzzer sounds for long.
Thanks in Advance.
-3
votes
2
answers
260
views
Are high frequency signals bad for circuits? [closed]
Why do we need capacitors connected to the ground when there is a high frequency signal? Are high frequency signals bad for circuits?
- 17
1
vote
2
answers
367
views
Powering ISO124P Isolation Amplifier
I need to use an ISO124P isolation amplifier. The data sheet for the device is here http://www.ti.com/lit/ds/symlink/iso124.pdf
My question is with regards to powering the amplifier. I am really ...
- 53
1
vote
1
answer
280
views
Can the M590E's boot pin be used to reduce power consumption?
What does the boot pin actually do? Can it be used to reduce the module's power consumption when the module is not required? All recommendations are to pull it low to boot. Can it go hi again to turn ...
- 149
0
votes
2
answers
669
views
Timer of 12 seconds using hardware circuit
In my design, say there are 2 pins A and B.
Now I want to implement circuit in such a way that B is initially high , but when A goes low, after 12 seconds B will go low for short duration and again ...
- 739
3
votes
1
answer
768
views
PSU metal case is live /
i have read quite a lot about this and i would like the experts opinion. I have an old dell desktop with a 250 watt PSU - PSU is grounded to the metal casing of the psu and the psu in turn touches the ...
- 31
0
votes
2
answers
6k
views
Old transformer input output
I have a transformer found on my old computer ups.
I dont understand its pin out. It has black and red lead one side. And on adjacent side it has four wires connected with a female connector.
I want ...
- 15
-1
votes
1
answer
312
views
need to identify "g7" chip or IC? [closed]
I have a corsair power supply.The computer will only turn on if I switch the power supply off and back on. Then I press the PC power button. If I don't do this and I shut down the PC and turn it on ...
2
votes
5
answers
5k
views
3V LED Pulse Circuit
I am trying to make a very compact and lightweight circuit that will cause an IR LED to blink on and off at a constant rate, preferably at least once per second but the flashes can be more spaced out. ...
1
vote
2
answers
1k
views
NodeMCU with two MQ gas sensors requiring multiple analog pins
I was very helpfully directed to this forum from Stack Overflow with this question.
So I've been working on some project for making air quality sensors and ran into a problem. As anyone who has ...
3
votes
1
answer
558
views
How can a voltage follower op amp amplify?
I have this circuit as a white noise source (with two outputs):-
So the 24V Zener diode makes noise due to a 60uA current. This is fed into two TL082 op amps. At the op amp input, the noise level ...
- 7,517