0
votes
0answers
3 views

Voltage Doubler capacitor types

I've got a virtual isolation transformer by connecting two 12V transformers at the secondaries, so the input to my circuit is an isolated 120VAC (US). I'm creating a 2 level Greinacher style voltage ...
0
votes
0answers
2 views

Is a dead diode actually a shorting?

I had a little project running with an arduino pro mini. had external psu connected and connected my programmer with power onto it. smoke came up. hole in the diode. now my question: Is a dead diode ...
0
votes
1answer
4 views

If adding resistors in parallel decreases total resistance, why doesn't the voltage in the circuit change?

I'm sure I'm missing something basic, but here we go: If adding resistors in parallel decreases total resistance, why doesn't the voltage in the circuit change? Does the current increase to match ...
0
votes
1answer
7 views

How can USB multiport HUBs extract enough power?

If I connect a 4, 6 or even 10 USB multiport HUB on one single USB port of my computer, how do the 4, 6, or even 10 connected devices get enough power? AFAIK, the single port (which is the bottle ...
-1
votes
0answers
21 views

LED strip lights up (faintly) with ground only

That's right with ground only (no positive voltage is supplied). But not all LED strip, only two diodes. When I supply positive voltage one of them won't even light up. Does somebody here encountered ...
0
votes
0answers
21 views

Tranmission line equations when initial conditions are not zero

A high voltage DC line is in steady state sufficiently long time after applying 1 MV at the input terminals through a DC voltage source of 30 ohm impedance with an open circuit at the load end. The ...
-5
votes
0answers
30 views

Altium, How to put Infra-red sender and or receiver into schematic

Where i can find the library for IR LED. Is there any builtin component in altium?
1
vote
2answers
145 views

Detect 3.5mm stereo jack plugged in

First off i'm using arduino as MCU. I have two internal speakers inside a box to output the sound from a FM Rádio Module, but i have also an stereo jack in my box, so anyone can plug a external ...
0
votes
1answer
18 views

Forming Norton generator from a voltage source and two resistors

Can I combine the E,R and Xl to form a current generator, with R and Xl in parallel. I need to find the impedance of Z so it develops most power, R-jX, or Z*, if Z is the impedance of the rest of ...
0
votes
1answer
43 views

Driving MOSFET gate using PIC

I would like to drive a MOSFET gate using 12V (in order to reduce the drain-source resistance). Using the answer from a few post i've read I have come up with the following circuit. Will this circuit ...
-2
votes
0answers
38 views

Why Battery Life Differs so Dramatically on Watches? [duplicate]

Trying to rephrase this question How Can A Cheap Watch Battery Last for 13 Years? with more details. Bought this watch 13 years ago, the battery is still going strong. However, batteries on several ...
-3
votes
0answers
35 views

ATX PSU to variable voltage and current supply (LM317?)

Yesterday someone drove by my house and dropped an old pc next to my house. I took it inside and inside of it I found some cool stuff. 2 1gb sticks of ddr ram, radeon hd3850 that I couldn't test ...
-2
votes
1answer
39 views

Mosfet identification

What mosfet is this? I know that it's N-Channel but where's the side of Source and Drain? I think, Source it's at right side, because of shifted Gate line... What's the usage of the two opposite ...
0
votes
2answers
31 views

Separating power ground from control ground

I'm looking at the 'layout considerations' for TPS61030. On p.18, it says Use a common ground node for power ground and a different one for control ground to minimise the effects of ground ...
0
votes
1answer
39 views

Building 7 Transistor Logic Gates using And, Or, Exor and Inverter

Hello I just want to know something.. For example, I have this: Let's say I build an AND Gate and an Inverter.. I check the and gate if it satisfies the truth table and upon checking it, it ...
0
votes
2answers
27 views

battery overdischage oscillation protection

I previously asked asked an advice on power control of battery operated system. The problem was to cutoff the battery when low to avoid overdisharge. I have built the device according to Olin ...
1
vote
1answer
23 views

STM32: Timer Modes

Is is possible to measure the frequency of an input analog signal with the input capture mode of Timers in STM32F4 ? If not, then what is the alternative ? Thank you in advance.
1
vote
2answers
40 views

Transistor Logic Gates in One Breadboard

How can I make a combination of the 7 Transistor Logic Gate and putting those gate in only one breadboard.? I've seen the combination on this Topic: How to combine multiple transistor logic gates ...
-5
votes
0answers
26 views

BJT or Mosfet for PID

I want to build a PID controlled Servo valve. I can't choose driver transistor which is best for linearity , fast response, working life. BJT or Mosfet? This is the amplifier schematic In the ...
0
votes
1answer
11 views

Is it possible to use a USB Wifi dongle with STM32F429I Discovery board?

I have been using wifi modules like ESP8266 and EMW3162, but this increases the load of work. I would like to use a usb wifi dongle (because discovery board has extra usb interface). Is it possible? ...
0
votes
0answers
13 views

PHY Initialization

I have a question about PHY initialization. I have a max24287 phy connected to TI ARM processor. The PHY is acting as a bridge between SFP connector cage (where an external phy device is connected) ...
-1
votes
1answer
16 views

Can DSO Nano V3 (BenF Firmware) measure AC 350v? [on hold]

DSO Nano v3 with BenF Firmware. Can this device measure AC volt safely? Does it have shutdown/disconnect capability when volt is above its measuring capacity? Thank you so much in advance for your ...
0
votes
0answers
27 views

Why do smoke alarms give three sequential beeps when they detect smoke? [on hold]

Why not, say, 3 short beeps or 4 long beeps? I know that 3 long blows of a whistle means "Emergency" - is that why smoke alarms sound the way they do in a potential emergency?
-2
votes
0answers
44 views

why are D'Arsenoval type meters kept at an angle?

All D'arsnval type Galvanometers, ammeters voltmeters are inclined at an angle to the base. Why are they kept so? Does this have anything to do with the efficient interaction of magnetic field and ...
-4
votes
0answers
22 views

LED Night Light 6V [on hold]

Im new to electronics and I want to make a Night sensing LED light. A LED light that turns on at night and turns off in morning when sun rises. Please tell me a circuit to make this simply as ...
-3
votes
0answers
16 views

What do these terms “boost”, “compand- compress and expand or normalize” mean? [on hold]

I wanted to try out this shadowing method but have no idea what majority of the author wrote means. I understand "low pass filter" and "slow speed"'s, but the rest I don't. Please help me with this. ...
0
votes
0answers
19 views

Burn Code using Code Composer Studio

I have been programming CC3200 using code composer studio. I know how to run the debugger on my device and run the the code successfully. But I can't figure out how to burn the code on my device so I ...
0
votes
1answer
37 views

Error Logic Gates [duplicate]

I connect this 5 transistor and,or,nor,nand,inverter respectively into to switches to operate.. I also add Exor and Exnor.. the Exor I made consists of 4 Nand gates based on the nand diagram stated ...
-2
votes
0answers
14 views

Circuit Simulator with multimedia capabilities for training [on hold]

Is there a circuit simulation software (SPICE) that gives the user the ability to add images and videos/sounds to different parts of the circuit for training purposes?
0
votes
2answers
21 views

Mixing 2v and 3V LED's and calculating resistors

Are series groups in parallel better than strictly parallel with a resister on each leg? And for parallel do I calculate Ω just for each voltage LED or do I need to somehow do a calculation that takes ...
1
vote
2answers
94 views

Audio Grade Capacitors - Marketing Hype or Better Technology

I have been reading a lot about audio grade capacitors lately, and I cannot find very good information about them. I have read many posts from different sites saying that audio grade capacitors are ...
0
votes
2answers
52 views

MOSFET driving MOSFET for reduced reduced Rds [duplicate]

I am using a PIC to drive the gate of a logic level MOSFET. Although the 5V logic output of the pic is sufficient to exceed the threshold voltage I would like to drive the gate using 12V to reduce the ...
0
votes
1answer
26 views

minimum load current vs stability

One of my previous classmates said "Low Drop Out regulator has a minimum load requirement and this is related to stability. It might affect start up overshoot." In the previous school project, my LDO, ...
0
votes
2answers
31 views

Combining 1, 2 or 3 audio signals so the output always has the same amplitude. LM3900

So I am outputting up to 3, 0-5V signals from three separate DACs. The issue I have come into is that I would like to combine all three signals to form a single output of the same amplitude. Currently ...
0
votes
1answer
26 views

Extending 500us pulse for multiple input signals and minimum IC count

I need to extend as fast as 500us input pulses to ~150ms for them to be detected by a downstream circuit. Pulses are coming from sensors. I've found other answers in this site and others about using ...
0
votes
1answer
24 views

extract gate level netlist from layout

My project is to extract a gate level netlist from layout, I am going write a parser for GDSII file format. However, I have trouble in relating the record information represented in the GDSII format ...
0
votes
2answers
50 views

12v dc motor rotate once and then stop

Can anyone suggest the best way to get a 12V DC electric motor (70RPM) to rotate roughly 360 degrees and then stop? So the process would be; Power switched on. Motor rotates once, then stops. Power ...
0
votes
1answer
15 views

Low voltage cutoff circuit with Zener and BJT

I have a circuit that's supposed to cut off at <4V. It instead caps the voltage at 3.3-ish and reduces the voltage linearly below that. Zener - 3.3v Source - 5V +-5V
2
votes
3answers
28 views

Difference between High- and Low- side switching of power?

Is there any real difference between high- and low-side switching? Assume: Switching is for on/off control of an object (My case RPi) Base/Gate can be driven to Vcc and GND
-2
votes
0answers
21 views

problem de-soldering mobile phone power button [on hold]

I need to replace my Galaxy S2 i9100’s power button. The following video demonstrates what I need to do: https://www.youtube.com/watch?v=1F6C13O76qk It looks really simple… de-solder the current ...
0
votes
1answer
67 views

Design to fit components in small space

I have to design the connections between different electrical components inside a wireless equipment. The "traditional" way to connect each one with the others is the PCB, but the particular shape of ...
0
votes
2answers
59 views

Combining resistors in series with a voltage source in between

Am I allowed to combine the resistor R and coil Xl as if they were right next to each other? I want to make this into a current generator, without many transformations.
0
votes
3answers
35 views

DDR3 Address Bus Quations

I'm new to EMIF (external memory interfaces) and I ran into kind of a dumb question about DDR3- not super important but mostly me just wondering if there's an answer I'm not thinking of. Basically I'm ...
0
votes
0answers
28 views

simple question about constant current led driver

I'm installing LED house number lights and connecting them to a timer switch. The only specs on them say voltage 6-12 V DC, and Watts: 0.045A at 12 Volt DC. I'm installing 4 in series so I think I'd ...
0
votes
2answers
43 views

Generating exact frequency of vibration with motors

I measured the frequency of motors with an accelerometer (ADXL335), but the frequency from my measurement is a lot different from the frequency specified in the product page. I tested with two ...
-4
votes
1answer
44 views

Qual a theoretical ability of radio spectrum? [on hold]

Digital TV (VHF) can currently transmit 31.67 Mbit/s. What would be the theoretical ability of radio spectrum band (UHF) and the maximum of the VHF spectrum?
0
votes
2answers
56 views

DPDT switch using only transistors

I have seen a number of similar questions but no one ever seems to actually answer this question, so let me pose it a different way. Let's suppose I am stuck on a space ship (so I can't go buy some ...
-3
votes
0answers
23 views

Send arbitrary Wi-Fi raw packets with ESP8266 and Teensy 3.1

I have a Teensy 3.1 and a ESP8266, and I want to craft special raw packets (such as ARP packets). I searched the web and I found a discussion on www.esp8266.com ...
0
votes
1answer
43 views

Correct design for large contactor circuit?

After some advice here I'm wondering if this is the correct design of my circuit. I'm now using a SSR as the control device to the contactor. The diode, I believe, should not only protect the SSR ...
2
votes
2answers
55 views

Using bit fields in interrupt-driven applications

When implementing interrupt-driven applications I usually create a bitfield to keep track of different interrupts. For example: ...

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