All Questions
0
votes
0answers
14 views
Multimeter showing 1 and low battery signal?
I have recently joined stackexchange ! and i'd really appreciate anyones help on the topics problem....
I have a mastech MAS803L digital multimeter and i was testing the voltage of chinese mosquito ...
0
votes
1answer
8 views
Programmer for MSP430F2274 TI microcontroller
I want to program that specific microcontroller (MSP430F2274) and i would like to hear your opinion on what programmer to choose . I prefer one that can be used with a linux machine.
So what you ...
0
votes
0answers
14 views
Horizontal Width on CRT
I just purchased a PVM-14M4a (14" Sony broadcast monitor) on eBay and the picture is far too wide for the screen (regardless of input, the OSD doesn't fit on).
I know this isn't a place to ask how do ...
0
votes
1answer
11 views
BJT Ic vs VBE graph in Proteus simulation
I'm trying to simulate the behavior of a BJT on Proteus.
The image below shows the graph that I got when I plotted \$I_c\$ on the vertical axis vs. \$V_{BE}\$ on the horizontal axis.
But ...
0
votes
1answer
20 views
How can I add sounds to my logic probe?
I am a beginner at electronics and I want to build a simple logic probe for TTL circuits. I found this diagram online:
Which does exactly what I want. However, I would like to make it play a high ...
-1
votes
0answers
10 views
Is it a problem if the driver colour depth is higher than the display panel colour depth?
I have an LCD Display Panel which works with LVDS (NEC NL10276BC24-13).
Now i want to buy a LVDS Interface to use the panel as a DVI-Display:(http://www.pollin.de/shop/downloads/D810221D.PDF)
In ...
-1
votes
0answers
17 views
Need an all in one “graduated” temperature/pressure/depth sensor
As the title says, I'm looking for a sensor capable of measuring temp/pressure/depth of a liquid in a container. Is there an all-in-one sensor available in the market that any of you people know ...
0
votes
0answers
15 views
How to select SMD resistor/cap size in ORCAD?
I am trying out the Lite version of OrCAD, version 16.6. I've been playing around with assigning footprints with ICs a little bit, but I can't figure out something as simple as a resistor or cap.
The ...
0
votes
1answer
18 views
Modeling Capacitive Discharge Ignition (CDI) Circuit
I am trying to model a capacitive discharge circuit (see Fig. 1 below), but I'm having difficulty properly coupling the two inductors on the transformer and also estimating the energy dissipated ...
0
votes
1answer
51 views
Choosing the right transistor for a switch
Based on a very closely related question: Choosing the right transistor for a switching circuit I have managed to create a working circuit, but I need the correct transistor.
Some context: I am ...
-3
votes
2answers
54 views
Separating the currents
I got a big problem that I have to put these to motors together like this but they have same working voltage but different currents and that's what makes the second motor doesn't work correctly ...
0
votes
0answers
38 views
The right motor for steel bending [on hold]
I apologize in advance as this query may be excessively rudimentary for your astute forum. What would be a good electric motor to use for the following metal bending application? I build disc ...
0
votes
3answers
76 views
How to make the hottest CPU temperature?
Besides just running an infinite loop, are there any tricks (like maybe cache misses?) to making a CPU as hot as possible?
This could be architecture specific or not.
0
votes
0answers
33 views
Divide By 5 Up Counter 6 to 10
How can I design a divide by 5 counter which counts from 6 and up to 10 then resets to 6. A normal divide by 5 counter is 3 bit counter which counts from 0 to 5 then resets to 0. I think my one should ...
0
votes
1answer
36 views
Help converting analog potentiometer to digital
I have a 3 dial motor control assembly that is using 3 potentiometers to control 3 independent 110v motors speed.
The label on the pots read TO50K 1339 (first O has a "S" like shape inside). I have ...
0
votes
1answer
21 views
Depassing 15V on Operational Amplificator?
So in the book it says we can obtain the following relation using negative feedback
(Out Voltage)=1+ R2/R1 (In Voltage)
The out voltage can depass +15 V , How can this be possible?
0
votes
0answers
13 views
Can't read/write to/from the atmega328p
I cant communicate with the Atmega328p. I've flashed fuses low: 0x59, high: 0xD9 and changed wiring. Now I've connected 16Mhz crystal to the XTAL1, XTAL2 pins, and 2x22pF to the crystal. But I can't ...
0
votes
1answer
51 views
Inheritance of properties
Is it possible to inherit some properties from the scope that we invoke a function? A code snippet might help more to explain:
...
2
votes
1answer
62 views
What is the output impedence of this RC Circuit
I have this simple circuit. And from what I calculated the output impedance seen from the OUT node comes to about \$138.765 \Omega\$.
$$ X_c = \frac{1}{2\pi * 890*10^3 * 10^{-9}} = 178.8257\Omega $$
...
0
votes
1answer
32 views
Sanity check: Input and output filter for a stacked pair of DC/DC converters
In my current project, I need voltages of +/- 30V and +/- 15V for analog control purposes. The current on the 30V rails is fairly limited, ca. 70mA max on one rail and <10mA on the other. The 15V ...
0
votes
1answer
23 views
Connecting multiple servos for a robotic arm
i am computer programmer and its really been long since i have done electronics. I need help on connecting my servos to an arduino to power my robotic arm. This is the robotic arm that i am trying to ...
0
votes
3answers
56 views
Transfer function of amplifier
Hello everyone, I would like to find transfer function between input signal \$U_1\$ and output signal \$U_2\$. So, I know how to find the transfer function of each op-amp, for example,
1 transfer ...
0
votes
2answers
59 views
All sorts of fail converting Schematic to Bread Board
Schematic:
Fritzing BB View:
Total n00b: I am trying to layout my breadboard based this schematic, but I'm not sure if I've even come close. The LM34 in the graphic is actually a SS494B hall ...
0
votes
0answers
20 views
Speaker Amplifier for First Alert Keypad
I am trying to get this circuit to work properly. It does work well with battery only, but when I add the 12VDC to 9VDC converter I get problems with audio making growling noise and the 200MFD cap on ...
0
votes
0answers
38 views
How long will my ~20W device last with a 18000mAh battery?
I have a Mac Mini with a max power consumption of 85W but an average power consumption of ~20W (in my experience). I'm thinking of buying a portable power source with a 18000mAh battery. How do I ...
0
votes
1answer
24 views
Comparison of the efficiency of DC motor current limiting / control methods?
I'm using the wheels and motors of an RC toy car as a simple robotics platform. The car has 2 motors, one drives the back wheels, the other steers the front wheels. The steering motor is stalled by ...
0
votes
1answer
48 views
Why should I use DC coupling when I'm finding the frequency response of a circuit?
In my last electrical measurements lab I was asked to plot the frequency response of several different filters (high pass, low pass, and band pass) using an oscilloscope. My professor told the class ...
0
votes
1answer
15 views
IF signal amplify without delay
I have a RF Frontend that has an 4 IF signal output (2 I channel and 2 Q channel from 2 receiving anettans). Each channel of the IF has a signal rangining from 1.5V to 3.5V with a DC offset of 2.5V.
...
2
votes
3answers
239 views
Current calculation in circuit
Please show me the steps to calculate current going through R1, R2 and D1 Led (Green color LED), when I tested this circuit through a multimeter it showed as 2.5ma across R1 and R2 but 0ma across D1, ...
0
votes
1answer
19 views
Minimum limit for current and maximum limit for voltage while calculating power
I have a brushless Motor then i am using in conjunction with a ESC, powered by a Lithium Polymer Battery(3S 1300mah). I just got a new Lithium Polymer battery (6S 15000mah) from a friend and am ...
0
votes
1answer
51 views
Increase toggling speed of PNP for PWM
I got a shift register which I use to PWM LEDs. Since I multiplex this toggling I noticed some "afterglowing" if the next LED is not active of the same color. (RGB cathode) Multiplexing by the MOSFET ...
0
votes
2answers
53 views
Choice of the appopriate conditional statement
I'm measuring the width of a PWM puls with the external interrupt:
...
1
vote
2answers
39 views
Set ground reference of a 5v DC power supply to the middle of a 24v DC power supply
I have 2 isolated AC/DC power supplies. one generates a regulated 5 volt power supply and other generates a 24 volt power supply as you can see in the picture below:
I also have designed a circuit ...
-4
votes
0answers
39 views
How to increase frequency to 13.56MHz in 12V 20A PWM? [on hold]
How to increase frequency 100Hz to 13.56MHz in 12V 30A PWM?
-2
votes
0answers
37 views
charging capacitor circuit diagram [on hold]
i'm working on energy harvesting project. and im looking for charging capacitor circuit with 5V input. the circuit can charge the capacitor and after full can lighting a LED.
one more thing is the ...
1
vote
2answers
76 views
Can a tank circuit store energy for a simple AC system?
If you take the circuit below, with the switch closed, assuming the Tank circuit is tuned to resonate at the same frequency as the source, then I would expect the tank to become charged, and the ...
0
votes
1answer
40 views
How can I work out if a cable can take a momentary current spike?
In this video here, almost 1000A is being run through a 10mm steel bar, and after a minute or so, it melts.
https://www.youtube.com/watch?v=YzZ3aJqmT-M
So in terms of charge, 60,000C applied for 1 ...
0
votes
1answer
28 views
Use DALI interface to power the device
I work on a DALI lighting system for home usage and I design all DALI devices from scratch. In this system, also a sensor module will be implemented. Since it will draw only a negligible current (app. ...
0
votes
3answers
41 views
High AC voltage affects the pcb
I had a PCB board printed that has some relays that are connected to 220 VAC circuit.
Now unfortunately some traces passes near the relays and are affected by this high voltage causing the circuit to ...
0
votes
1answer
20 views
How to calculate the variance of a discrete signal?
Explained as:
'the variance of the signal is the mean of its squares minus the square of its mean'
The mean of its squares (average of instantaneous power of all samples) minus the square of its mean ...
0
votes
1answer
20 views
Low-Voltage DC Power Line Communication IC
I am wondering whether someone can recommend/suggest an integrated solution for Power Line Communication over low-voltage (4.5V-18V DC), short distance (<20m) wires.
Discrete solutions involve a ...
2
votes
0answers
49 views
Mold (Fungus) build up on PCB
I have been running small batches of production over a year without a problem. Today, I found a problem that is never happened before. I have changed the PCB to gold plated in my recent batch and I ...
0
votes
0answers
27 views
Piggyback off Motherboard Power Switch?
I have a custom computer with a custom case that I would like to re-purpose the power switch on, but only when the computer is running.
I have a Teensy board (similar to Arduino) inside the case that ...
1
vote
2answers
74 views
How reliable or trustworthy are LTSPICE demo circuits?
I'm looking at a few switching power supplies and one of the demo .asc files for the particular controller I was looking at really seems to fit my requirements.
Can I use their schematics in designs ...
0
votes
0answers
10 views
Trouble in proteus isis
I need to design a few components in Proteus. Due to complexity of the design ( and size of circuit), I decided to use the sub circuit feature. I made a block diagram of my design and edited its ...
1
vote
2answers
67 views
Diode Drop vs Open Drain Output Tolerance
I have an LED Driver IC that states a 5.5V tolerant Open Drain Output. It's Absolute Maximum section indicates 6.5V with a note saying "The input negative-voltage and output voltage ratings may be ...
-1
votes
0answers
17 views
Programmer for Freescale CodeWarrior and MC56F80x family Digital Signal Controllers
I have a sample Freescale digital signal controller (MC56F8006) that I would like to evaluate for a motor driver I am building.
From what I can determine from a search of Freescale's website, you ...
1
vote
3answers
120 views
Why can't different current sources connect in series?
I've posted different question similar to this, yet still struggling to understand the theory. So here is another attempt to understand as to way two power sources(with different currents) connected ...
0
votes
0answers
10 views
HSPICE - Measuring a series of values in transient simulation
I'm doing a transient simulation in HSPICE with an input vector file of N values (N>100).
I would like to get at each rising edge of the clock (i.e. timing of the shape kT, T period, k integer) a ...
1
vote
1answer
31 views
pH sensor project: trouble with RF interference
I built this pH sensor project on a breadboard and I'm having a big problem. The output on the voltmeter is completely erratic, and I'm pretty sure it's due to RF interference. When I connect the ...
