# All Questions

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### Need Help: Wiring LEDs with 2 source voltages

I have a series of LEDs I would like to have display at 2 brightness levels and am confused how to properly wire this. This is for additional running lights/brake lights on my bike. LEDs - Typical ...
5 views

### How to repair a battery?

I used this battery pack with this charger for about a month. And yesterday I've left the battery plugged into four ESCs of my quadrocopter. Today I've found the battery totally discharged. When I ...
40 views

### How to realize this transfer function with OP-AMPs?

This is a homework question. I know that: Given a transfer function of $H(s)$ below, we can realize it with an OP-AMP as follows. ...
25 views

### A heat sensor that powers an LED with no controller

I'm a programmer, and I can wrap my head around having a controller board which monitors a temperature sensor llike this ...
12 views

### VHDL - Convert from binary/integer to BCD and display it on the 7-segment display

As part of my project for the Digital System Design course I have to use a component to display on the 7-segment display a INTEGER range 0 to 9999 (or a std_logic_vector(13 downto 0)). I used the ...
59 views

### Controlling the turn on/off of a 380-440V high voltage water pump

I'd like to control the turn on/off of a NFw Series Centrifugal Water Pump 380-440V high voltage water pump using an Arduino. I have searched for how control it, but I haven't found any ideas. Can ...
29 views

### What is a “santa cruz interface”, who created it?

There is HSMC that I have seen, but Santa Cruz just looks like regular pin header. What is so special about it? And why is the word Santa part of the name?
50 views

### Weird current at 8051 port 1 pin

The pins in Port 1 has internal pull-ups when used for input. The Mosfet is off and the drain is pulled high using an internal pull-up resister. I connect an ammeter and see that the current (IL ...
9 views

### gSpice: 'model is not a mosfet' error message

I'm trying to simulate a circuit. So: I run netlist on the .sch file. It completed successfully. I've opened the .net file ...
11 views

### Phase Angles in Series/Parallel networks. !! I'm Lost !!

INTRODUCTION: I've been having a hard time in class trying to understand phase angles. I understand a few concepts which I've stated below for clarity in regards to this discussion. 1.) ...
979 views

### Is there a way that you can get a Portable/Online Arduino IDE?

I am just starting out with the Arduino, and I want to develop and create sketches at my school. The only problem is that the school's computer doesn't allow any application to run if app tries to ...
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I am seeing a strange behaviour on an I2C waveform, and it is causing an incorrect bit to be read by the master. The master device is an ET1200 EtherCAT ASIC, and my slave is a CY8C3666LTI PSoC which ...
23 views

### common mode choke inductance question

In a common mode choke, my understanding is that common mode currents will produce fluxes that add together, which increases the effective inductance between them and so attenuating these currents. ...
46 views

### Stable voltage and current source

I want to build a simple and stable constant voltage source (voltage regulator) and current source. I built one using a LM317 but the output is not stable, it varies when temperature changes. Do you ...
121 views

### Efficiently driving 8 low-current Optocouplers

I'm looking to drive a bank of eight FOD4216 random phase triac drivers. I'm looking specifically at the (insanely expensive, \$3!) Fairchild FOD4218, which needs 1.3mA to switch. 8 * 1.3 = 10.4 mA ...
33 views

### Eagle part for “MiniLED” SMT LED

I'd like to use this LED, but its package is just listed as 'MiniLED' in the datasheet. Is that a standard package, or just a Vishay term? Is there an equivalent part already in Eagle 6? If not, ...
20 views

### DDR2 Data Mask Pins [closed]

I saw that last year you had a problem with the data mask pins on a DRR2 memory. I was wandering if you have tested your solution connecting the DM pins to the Ground. I would really appreciate a ...
23 views

I am designing an Xbee mesh network, planned size is around 10 nodes spread around 200 square metre area. It will be a combination of nodes reporting environmental data with actuators/loggers. I ...
46 views

### Can i directly connect this chip to PC and how can i amplify it (NRF24L01)? [closed]

Can i directly connect this chip to PC and how can i amplify it for increased range (NRF24L01)? for more: http://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=765
19 views

### Verilog Netlist and verilog file not justifying each other

i generated a verilog netlist file with the help of a test case for 2-1 encoder .To test the netlist i draw the schematic diagram and try to find the output.I can't upload the pic of schematic which i ...
41 views

### Dimming USB Led Lamp

So, currently I have a project that consist in the following: We have 2 USB Led lamps. (e.g 13 leds, 5V, ~200mA) To these lamps, we would like to control the intensity of the light, through a ...
24 views

### Recommendations for an FPGA that meet the listed criteria [closed]

I am looking for an FPGA + dev board that will meet the following specifications. As I know too little of the market, I am seeking your advice for a system meet the following specifications. Must be ...
60 views

### Where can i find the datasheet for this component (RF2001)? [closed]

Where can I find the datasheet for this component (RF2001)?
80 views

### Using a 7 segment display to show numbers 1, 2, 3 and 4 with four inputs

I have in my car 4 LEDs which illuminate in the instrument cluster depending on the gear the vehicle is in. This is a factory standard setup which I have already run feeds from ready for the next ...
100 views

### Can I hook this breakout board up to the thing I want to measure?

I have a piece of tech that uses somewhere between 50-200mA, and I want to continuously measure the current used. To this end I have found this: Sparkfun ACS712 breakout board Allegro ACS712 chip ...
99 views

### Controlling Microcontroller using Visual C# [closed]

I want to control some motors from the Microcontroller but I want to control the Microcontroller from the computer using C# or at the very least get some feedback to the computer How can I do that ...
43 views

### Crystal oscillator “voltage control” pin usage [closed]

What does "voltage control" mean for a crystal oscillator? For example where a crystal oscillator marked "40 Mhz" has a control pin. Can I use PWM to control it?
370 views

### What to look for in a multimeter?

When selecting a multimeter, what should one look for in terms of safety features and measurement capabilities? What can you look for in the specifications to tell a good meter from a crappy one ...
60 views

### How could extension cord detection be implemented in Tesla Roadster?

Googling finds evidence that Tesla Roadster electric car can detect cases when it is plugged in via extension cord. Specifically this page lists error codes 937 and 9 meaning "extension cord ...
149 views

### Likely places to look to find cheap sources of FPGA? Which devices should I open first?

I have a large group of new and old devices and I would like to find a FPGA to start poking around on. What products or types will be likely to have FPGAs in them? I recently asked this question on ...
112 views

### Recommendation for ADC noise filtering?

I'm using an ADC (adc081c021) with a pretty noisy input: There is also a 5-second video here: http://tinypic.com/player.php?v=2ue47cm&s=5 The objective is to detect the two peaks. How could I ...
40 views

### Using a N-Mosfet to switch a common cathode ledstrip

I am trying to drive a RGB-ledstrip using the following circuit: http://learn.adafruit.com/rgb-led-strips/usage As I am using a Common Cathode led-strip instead of a Common Anode one as used in the ...
35 views

### How much max distance of SPI & USB & I2C and TWI(without any IC [closed]

How much max distance of SPI & USB & I2C and TWI(without any IC(my mean is directly)), and how can i amplify these?
32 views

### Capacitor discharge [closed]

I have a 1 microFarad capacitor and the range of the capacitor is 400 V. If I apply 315 V to the capacitor how many Volts will the capacitor discharge ? How to calculate the discharge of the ...
27 views

### value of variable in Veriog not defined

I am analyzing a verilog file for always. in this, what should be the value of "en" in case first and then in second? ...
38 views

### Arduino Uno as a programmer for AVR chips

I am trying to make an Arduino Uno act as an external programmer for an ATmega32 and ATmega 8. I couldn't succeed, I used connections as given at Using an Arduino as an AVR ISP and Arduino Uno as an ...
30 views

### Why sometimes i should use RS232 (or another chip for another protocols)? [closed]

Why sometimes i should use RS232(or another chip for another protocols)?
69 views

### I don't understand what are the difference between UNO and Leonardo?

I found that they sell UNO Starter kits and Leonardo Starter kits. There are many different products. My eyes are so busy. I am a greenhand. If I want to buy a stater kit, which one should I buy? UNO ...
42 views

### Help required performing Single Master - Multiple(upto 16) Slave SPI Communication using MSP430

I am planning to use MSP430F6638 for SPI Communication between a single MSP430 Master and multiple MSP430 Slaves. I am using a 4x16 Multiplexer before each Slave for providing the Chip Select Signal. ...
28 views

### ATtiny85, ARduino IDE, TinyDebug: Error sending int values

The setup: An ATtiny85 is programmed using the Arduino IDE, it is supposed to read the ambient light from an LDR and turn on/off an LED accordingly. To get a better understanding of what my sensor ...
31 views

### AH276 hall effect sensor with microcontroller (sensor already in circuit - brushless fan)

I'm currently trying to read an AH276 hall effect sensor using an AVR microcontroller. The sensor is built-in in a brushless fan I'm using and it's operating as the fan's controller. The sensor has ...
22 views

### Measuring power consumption / current of an Arduino using a multitester

What is the correct way to measure the power consumption and / or current draw of an Arduino using a multitester?
248 views

### Zener Diode Circuit Sees Voltage without source applied

I have a circuit into an optical isolator which is used to detect the status of a contact in the field. Zener diodes are used in series to drop the voltage to the optical isolator as well as as ...
47 views

### Need your knowledge on cameras

I have to design a system which works with a camera device. To explain briefly, I need to get image information and I need to send some information to my vision system, such as shutter speed, trigger ...
67 views

### Arduino solenoid project behaves strangely when operated on PC power supply

simulate this circuit – Schematic created using CircuitLab I am trying to control a solenoid using an Arduino Uno. I followed instructions described in the tutorial Controlling solenoids ...
161 views

### DC DC Converters in Parallel for double current

I am using a 15V 7A DC DC converter for powering a robot. I am looking for a 15V 20A supply. For this can I put three of those regulators in parallel and expect them to provide about 20A of current? ...
178 views

### Video Composite signals

What are the considerations for PCB layout, and connector selection for video signals. Is it necessary to follow 75ohm impedance criteria in a closed system. The pipeline starts at Sony FCB IX 11 A ...
21 views

### How to match this given circuit to a model for a simulation?

I have to simulate the electric field within a gas filled discharge gap generated by a radio frequency voltage generatio. The circuit, provided to me by the experimentators somewhat far away, is given ...