All Questions

6
votes
1answer
1k views

Running network cable near X-Ray equipment

My mother runs a small veterinary clinic. She is getting a new X-Ray machine that will need a network connection to send digital copies of the X-Ray to the server. I will be installing a wall plate ...
0
votes
2answers
1k views

how to calibrate temperature sensor IC DS1621?

I have made temperature indicator using microcontroller P89V51. My temperature sensing IC is DS1621. I'm using LCD for the display..n ckt is working very fine, Do I have to calibrate this IC? If yes, ...
1
vote
2answers
445 views

Pierce oscillator issues

I am having a problem with Pierce oscillator designed to work with my SMART Card reader. I am using 3.58MHz oscillator, 74HCU04 gate IC for the NOT gate, and both 22pF capacitor and 1Mohm resistor. I ...
0
votes
4answers
371 views

Rework station recommendations?

We're looking for a decent hot air SMD rework station to help us fix up our prototypes. In the past, I've used one of the low-end Aoyue models, and found it lacking (the interface had problems, and ...
2
votes
4answers
2k views

Implications of short burst transmissions in radio? (SDR/gnu-radio)

First of all, I do not have an electronics background. I have recently been experimenting with software radio using GNU Radio and a USRP1. I came here in hopes that some people outside of GNU Radio ...
0
votes
1answer
317 views

Voltage follower with thermal protection

Could someone suggest a voltage follower with thermal protection (thermal shutdown)? I see possible solutions: An LDO with external reference. I found only few of them, seems they are called ...
2
votes
3answers
2k views

Using K-type thermocouple to measure human body temperature

Is there anything I need to he aware of when using K-type thermocouples? I got the idea by touching the probe. I can get a reading when measuring temperature for 30 seconds using a DMM. A commercial ...
0
votes
2answers
4k views

Measuring Home Water Flow

I recently purchased an Arduino Uno and I've had lots of fun tinkering with it. I'm now interested in measuring the amount of water that flows into my house through the water line. I'm having trouble ...
0
votes
4answers
464 views

Multicore Prozone Alternative

At college we have to use a colophony-free solder, but over heating the solder leaves the flux residue on the boards(light amber in colour). Multicore recommend there own Multicore Prozone cleaner(...
9
votes
3answers
974 views

Is there a name for “chips out of which one can build a CPU”?

Some people enjoy building "homebrew" CPUs out of simpler ICs. Is there a name for "chips out of which one can build a CPU, if you have enough of them"? Is there a name for the other chips, "chips ...
0
votes
1answer
284 views

Connecting an external control to a DPDT switch

Anyone familiar with the SMD1 Stepper Motor Driver Kit ? I am trying to figure out how to connect external control to the lugs on the switch assembly (DPDT push switches). The lugs already have the ...
8
votes
5answers
2k views

How Do You Prototype with QFP-Only Components?

I'm starting to design a circuit that includes a QFP-38 component. I'm accustomed to using DIP components and prototyping on a breadboard, but in this case I won't be able to acquire a DIP version of ...
0
votes
2answers
921 views

Get value from LDR

I'm using the picdem 18F4550 with microchip v8.63 and the c compiler. components that i'm use are: - 3 leds (red, green, blue); - a LDR (327700 NORPS-12 farnell). I have connected 3 leds (red, green ...
0
votes
1answer
1k views

Problems deriving state diagrams

If I understand correctly, the state diagram of a sequential circuit simply shows the different states the circuit goes through. However, if I'm trying to build a 2's complementer using a shift ...
1
vote
2answers
689 views

burn a led with the switchs on pic 18F4550

I'm using the pic 18F4550 with microchip v8.63 and with the C compiler C18. I want to trigger port RB3, RB4 and RB5. when, I press on respectively S1 (switch 1), S2 switch (S2) and S3 (switch 3). on ...
1
vote
1answer
498 views

Learning about the Interrupt system of the 8085 processor

I am trying to investigate the RST5.5, RST6.5, and RST7.5 interrupts on the 8085 microprocessor. I want to find information about the to the type of interrupting signal used and the built in ...
2
votes
3answers
863 views

Jig for making jumper leads?

Does anyone know of a tool that can make jumper wires to fit standard spacings for breadboards? What I have in mind is a jig where you dial in the number of rows you want the jumper to span, insert ...
0
votes
2answers
1k views

How to read RCA output from an mbed?

I'm wanting to buy this IR camera but it says it has RCA output. Is it possible to read this into an mbed without external components(aside from a 12v power source)? If so, how?
0
votes
3answers
3k views

How to figure out the pin out of this undocumented LCD?

I have a very tiny LCD ripped from a piece of electronic scrap. The LCD is about 1 inch by .25 inches. It does not include a backlight(it had an external LED functioning as the backlight) and is ...
5
votes
2answers
3k views

How can I locate items from a phone? RFID?

I'd like to be able to put something small on items (eg glasses, car keys, etc) and have an Android or iPhone app that will tell me the direction or proximity of a certain item. Current phones usually ...
0
votes
1answer
799 views

ATtiny44 not responding to AVRISP mkII programmer

It's not responding to the programmer at all in avr studio. avrisp attiny44 mosi -- - mosi miso ---- miso sck ---- usck reset ---- reset Or can it not ...
15
votes
5answers
1k views

How Do You Decide Between Analog Chip Manufacturers?

I'm an electronics beginner and I find myself often needing to pick an IC for an analog application with no prior knowledge. In the domain of microcontrollers, it's very clear that I should use Atmel ...
5
votes
3answers
4k views

Will my HEX file fit in my microcontroller?

I have a hex file with a size of 42 kB. Does the size matter while loading it in a microcontroller? Can I load 42 kB hex file in a ATMEGA32 chip which has a memory of 32 kB?
0
votes
2answers
271 views

What does line width mean for LCD

I'm new to electronics. I'm trying to interface my lcd with an avr but I don't think my code is initialising the lcd properly. At the top of header file for the library am using, I have this define ...
4
votes
2answers
453 views

What are these wires with pre-attached connectors called?

What are these connectors commonly called, and what would I search for if I wanted to buy sets of male/female pairs with a specific gauge of wire pre-attached?
5
votes
3answers
2k views

What determines the transmit frequency in this 555-based transmitter?

I'm a general class ham, and am just starting to do my own homebrewing. I was planning on basing a QRP transmitter off of this instructables project, seeing as I have a veritable plethora of 555 ics ...
0
votes
1answer
237 views

Flat panel that outputs light - to be used as a replacement for an EL panel

I'm trying to create a lit surface similar to a backlight for an LCD display (I'm replacing an EL panel in an arcade machine). For various reasons I don't want to just replace the EL with more EL. ...
4
votes
3answers
3k views

Can I use a subwoofer as a linear actuator?

I need an actuator with a few mm of travel and it has to be very responsive to a very low frequency (DC 10 Hz) sine wave generated by a function generator. I'm thinking of getting a cheap subwoofer ...
2
votes
2answers
2k views

Simple current flow

Referencing ground circuit simulator(link launches a simulator applet) Why doesn't current flow in the resistor in the bottom right? What do I need to read about electric theory to be able to ...
2
votes
1answer
2k views

How does the 4017 decade counter drive a set of servos?

I have just become aware that people are using 4017 decade counters and an Arduino to drive relatively large numbers of servos from relatively small numbers of pins. Not being an Arduino connoisseur ...
3
votes
5answers
2k views

Interface a high-quality camera to a computer in real time?

I have a project that requires high-quality video and stills to be acquired (almost) live with computer controls. By "almost" live, I mean that a five second delay is acceptable, but five minutes isn'...
9
votes
6answers
14k views

Increasing Voltage

I have a binary signal, 0V to 1.4V, which I can't change directly. What circuitry, (on a PCB) can I use to increase 1.4V to at least 2.5V. Do I need a transistor? I guess I'm looking for a switch ...
4
votes
6answers
5k views

Very high current very low voltage application

I'm not an electrical engineer. I have an unusual need and would like suggestions as to how to proceed. I have an application that needs very high currents at very low voltages. I'm trying to heat a ...
3
votes
3answers
3k views

Any problems with “floating” an oscilloscope?

I have a Chinese scope with a two-pin power cord and a plastic body, and measure megaohms between its ground terminals and the actual earth, so I believe it has an internal isolation transformer (I ...
1
vote
1answer
327 views

How to reverse cellphone firmware

I want to get full list of supported AT commands and other undocumented codes for some cell phone. I found that using strings command (on linux or win alternative) ...
4
votes
3answers
3k views

Playing a low res WAV/PCM file using a Basic Stamp II microcontroler speaker

Is there a way to convert PCM data to PWM impulsion so that I can send it a basic stamp microcontroler in order to play audio on a external speaker ? (without using an IC)
12
votes
6answers
13k views

How does this rectifier work?

In a car battery charger, I found a strange rectifier. Can someone explain to me how does it work? Here I have a transformer which is unmarked. By measuring resistance between its output terminals, ...
1
vote
3answers
1k views

Best way to drive a 20 kg object on a turntable? [closed]

I need to rotate an object about 20 kg's in weight, 360 degrees. I'm thinking of using a stepper motor with some kind of rubber wheel pushing along the rim of a lazy-susan. Geared or belt solutions ...
0
votes
1answer
138 views

What's the name of this component's package?

The device is called KY 717 and from what I've been able to find out, it's some sort of rectifier. The solder tab is insulated from the rest of the body. I was unable to make a better picture. The ...
0
votes
2answers
145 views

LCD rows not all lighting up

I'm wondering if I've blown my lcd by accident. It's supposed to be a 20 * 4 rows lcd however only row 2 and row 4 seem to light up. Should they not all light up
8
votes
7answers
9k views

Cheap method to drill neat holes in plastic casing?

A good deal of projects I see have their inputs and outputs neatly aligned in to plastic enclosures. I wish to do the same, however, I do not own a drill or anything similar. What is a cheap but ...
1
vote
2answers
846 views

ATMega 328 AREF and PWM/analogWrite()

I'm have a project which is using an ATMega 328 which is powered by 5 volts. It is connected to an accelerometer/gyro breakout board through a 3.3 voltage regulator and supplying the 3.3 volts to the ...
9
votes
5answers
3k views

High Resolution ADC for Noisy Sensors in Variable Conditions

Intro In response to this question about adaptive amplifiers, It was recommended that in order to deal with variable conditions, it may be more economical to simply use an ADC with higher resolution ...
6
votes
2answers
826 views

Is it possible to detect battery chemistry?

I'm looking at making a universal battery charger. And I am interested in seeing whether I can get it to detect the chemistry so if a non rechargeable had been put in it won't charge.
6
votes
3answers
1k views

How to build a constant magnetic field source for a “railgun”?

I'm trying to build a device similar to railgun. It will have two rails and a conductive movable bar in-between. At one side, I'll provide voltage source and a resistor. If I put it in a strong enough ...
0
votes
1answer
171 views

Safely detecting lead-acid battey charger output?

How can I safely detect output of a car battery charger? It has a OS/MP switch and for output it lists 12 V and 10.1 A. Unfortunately I have no idea what OS/MP means and I of course have no manual. ...
1
vote
2answers
626 views

Books on line codes?

Would you recommend any good book dealing with line codes (i.e. http://en.wikipedia.org/wiki/Line_code). I mean a book that goes a little bit deeper into properties of each encoding (e.g. spectrum). ...
4
votes
2answers
3k views

How do I determine the power rating of a stepper motor?

I have in my possession two stepper motors that are clearly marked as 50 ohm, 22V motors. They have six leads each, which I believe makes them unipolar stepper motors. It is my understanding (and ...
2
votes
2answers
3k views

11-16V DC voltage stabilization for 13.8V powered ham radio

I am looking for any resources on how to construct a relatively high power (25A, 13.8V) voltage stabilizer (or voltage booster if you like) for my 13.8V powered ham radio. The problem I try to ...
5
votes
2answers
1k views

what does “70A moy/arit 90A eff” on a high-current automotive lead-acid battery charger mean?

I have a huge (28 kg mass) automotive high-current battery charger, and its current delivering capabilities are described like that: 70A moy/arit 90A eff What do ...

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