Crotech 3133 25 MHz oscilloscope
Has any one got a user manual for a crotech 3133 oscilloscope for sale, or know where I can obtain one cheers Tom.
View ArticleNeed Help Making A DC 12 V Adaptor
Hello, I have a Sony PS-LX295 turntable, and it is supposed to be powered by a Sony TA-AX295 receiver, I believe. I know it is DC 12 V, and I want to make an adaptor, but I don't know the amperage. I...
View Articleultrasonic speakers
Hi, for a home project I'm looking for ultrasonic speakers (tweeters) with a frequency range of more than 30 KHz with a power of about 100W. Where can I buy them? Thanks, Marc
View Articlelooking for RS485 hub
Hiya, I cant seem to google up what i want, so im wondering if anyone here has any experience in rs485 networking, and knows of a suitable hub to use. The setup; i have 8 banks of rs485 nodes. each...
View ArticleLevel Conversion Between CMOS And RS232
Hi, I am trying to find a CMOS chip which can perform conversion between RS232 and CMOS levels. I've heard of the MAX232 chip but havent found documentation and I dont know if it is CMOS or TTL. If...
View ArticleWhy Are There No Right Angle Traces?
I was told the other day that there are no right angle traces on PCBs (the traces go to something like 45 degrees between perpendicular traces) because of something to do with something or other. Could...
View ArticleMeasuring ground moisture level via conductivity
A few weeks back, I posted a question about measuring the level of moisture in the ground (so I could control my sprinkler system accordingly). "The Captain" sent me a schematic that did this using a...
View ArticleDo they make cree night lights now?
I'm looking for a super bright LED night light, to light up a room a lot more at night than the old tech night lights. I realize that the "number of LED's" is meaningless, I just want lumens. Weren't...
View ArticleRe: Test phone jack without service subscription?
"Anti-Robo" <dubya54@XXXXyahoo.com> wrote in news:uueCq.81934$ql3.18802@en-nntp-12.dc1.easynews.com: > Can you test phone jacks if you have no landline phone service? Any > kind of voltage...
View Articlesafewatch 2000 security system
Does anyone know how to change the monitoring phone number?
View Article1000 year data storage for autonomous robotic facility
Hi! I'm planning a robotic facility [3] that needs to maintain hardware (exchange defective parts) autonomously for up to 1000 years. One of the problems is to maintain firmware and operating systems...
View ArticleDigital Converter (over-the-air) to Digital Cable Converter
Hi, I recently bought an "Access HD" model DTA1010D digital to analog converter for over-the-air digital broadcasts. This works fine for over the air digital signals, but it doesn't work on digital...
View ArticleHow can I increasing output voltage/amplify my laptop's sound cardheadphone...
How can I increasing output voltage/amplify my laptop's sound card headphone jack. Tia sal2 Greetings All I'm generating different sound waves using my laptop and outputting the sound via my laptop's...
View ArticleToshiba TV model 27A44, Regulated B+ Info
Hi, I have a Toshiba TV (27" pic) model 27A44 (mfg. 05/04) in my TV service shop (no SM). Customer told me the TV "sparks" once in awhile, then turns off. It didn't do it in the shop yet, but checking...
View ArticleT/C pile switch
Hi, I have following problem . The Thermopile probe ( 0.5V output @ 600 Deg C with internal resistance 2 Ohms ) drives gas valve solenoid with very low resistance ( approx. 0.023Ohm ) . Approximate...
View ArticleTesla Science Project
Super Tesla Coil Science project. Also, plans for a homemade Cathode Ray Tube, Plasma Globe. Ck. it out: http://www.primeline-america.com/science/
View ArticleHow to measure impedance of the grid.
Dear All, I am looking for a way to measure the impedance of the power grid. The problem is: I have photovoltaic cells which are pumping power into the grid when i do not use that much power myself....
View ArticleCan't determine laptop polarity - HELP!
I have a Gateway T-6815 laptop. The power brick was lost a while ago. I now have a generic laptop power brick. I cannot determine the polarity that the laptop needs? There is no tip/ring diagram. All...
View ArticleHow to keep a power up spike out of a battery charge controller?
I'm having a problem with a circuit that I did not design. The unit uses Lithium Ion batteries (laptop battery pack) when AC is not available. The problem is, when the unit is turned on with the...
View Article100 W amplifier schematic
Hi, I'm looking for a design (schematic etc.) of a 100W amplifier (more or a bit less) that I can nonnect to a sinewavegenerator for a frequency range up to 30kHz. I want to use a piezo tweeter. Please...
View Articletotal inductance of bucking coils
I need to be able to calculate the total inductance of two coupled coils when one coil is wound in reverse. I have a Boylestad's Introductory Circuit Analysis (old - 6th edition) that has a section...
View ArticleOscillometer, analyzer for slow computer
Hello, I have a Pentium I (64Kb RAM) with win 2000 and I want to use the sound card for 'animation oscilloscope, vectorscope, analyzer' the output of my amplifier. The measurement is not really...
View ArticleCalifornia audio labs CL-20
Good morning dear friends, I am looking for the service manuals of the Califirnia Audio Labs CL-20 DVD. It plays all the dvd's but in some of them it pauses (freeze) at the end!! (the one it makes it...
View ArticleHelp with transisitor circuit
I don't know much about electrical circuits beyond Ohm's law, but I have a project that I would like to solve. Attached is a schematic involving two circuits and a power transistor. Basically, circuit...
View Articleinfo of 74hc4051 maximum volatge needed
Hi I want to read many analog inputs from 0....24 V . I want o use one multiplexer. I think the 74hc4051 is the most common. My question is in case of overvoltage over the supply rails at the inputs...
View ArticleWhat is a BP73001A Murata filter?
Hi, I have a large lot of Murata filters. And I am searching the datasheet, or at least some information. On the box it says LK-BP73001A01, where the 1 might be a I, and the last O an 0 (oo and zero)....
View ArticleAudio from a cordless telephone (AT&T E5862BC)
Hello - I've got an AT&T E5862BC cordless telephone. There are two stored messages that I would very much like to transfer out of the answering machine section (the only two recordings of my passed...
View ArticleElectronic Distance Measurement - Help Wanted
Hello, A group of high school students is working on a project which involves using ultrasonic sensors to measure small distances (around 6 to 60 inches). There are a large number of possible...
View ArticleAltera Flex 10k probleem
Hi, I have a problem with bringing out the INIT_DONE puls out of an Altera Flex 10k EPLD. I use Quartus II software on a PC. I also use the EPC2 configuration device. I enabled this bit in the design...
View ArticleTips For Installing A Headphone Jack
I just purchased a new Apex stereo TV/DVD combo with many bells & whistles EXCEPT a headphone jack. Have any of you readers been able to successfully install a stereo headphone jack into a stereo...
View ArticleElektor EPROM Emulator flaky
I constructed the EPROM Emulator published in Elektor magazine in the SEPTEMBER 1992 issue. It worked quite well under Win98, but lately I started using it on a HP Compaq nx9010 Pentium 4 laptop using...
View ArticleSerial Port Design for Z80 - Questions
Greetings! I wanted to add a serial port to my 1981 Gorf arcade machine. Since it is really just a specialized Z80 computer, I was just going to tap the signals from the Z80 pins and create a small...
View Article220V Electronic ballast
Does anyone have a good site to purchase electronic ballasts in Canada? I bought a shower with a circular T9 fluorescent bulb in it, but the SCRs on the ballast started smoking the second day the...
View ArticleClik here to view.
Frequency Standard - GPS or Rubidium?
Hi all, I'm looking for some sort of frequency standard (10 MHz ref.?). Ebay has rubdium standards for under $100.00 and there are GPS controlled OXCO standards for $100.00 plus. My question : Is a...
View ArticleSafety considerations
For years, some retail and restaurant chains in the United States have been equipped with non-ionizing sources positioned to provide floor coverage. They emit a directed modulated beam, tuned to mimic...
View ArticleSegger Flasher 5 Programmer
Looking to buy a used Segger 5 programmer to read existing data from ST9 MCU. Thank you ... Please reply to jrepairman at gmail.com
View ArticleAnyone make a current/voltage watt-hour meter with RS-232 output?
I want to impliment a PC-based data logger for my home energy usage by measuring my total current, voltage, and power readings at my main breaker. I know there are products that do this and have...
View ArticleVariable Binary Counter?
Hello, I'm putting together a circuit that uses a binary counter to cycle through addresses of SRAM. I would like to vary the number of addresses used while the circuit is running. Does anyone know of...
View ArticleLM3478 design gets insanely hot
Hello Experts, This is my first time designing a SEPIC type switchmode power supply with the LM3478MM from national as my controller. My design is pretty much the standard application as shown in the...
View Articleoftware program that can do audio frequency sweeps tia sal2
Greetings All Can someone recommend a good software program that can do audio frequency sweeps through the computer sound card, without me having to type in and test each frequency separately. Example:...
View ArticlePulse sequence from camera I.R. remote
My Canon G2 has an InfraRed remote shutter release. Is there any way I can find out what is the timing and frequency of the pulses it transmits? I hope to make a timer that will take an exposure every...
View ArticleNeed 2 ms hardware timer
I am looking to implement a 2 ms hardware timer function. Condition is the Input goes from High to Low and stays Low indefinitely. Output should be a 2m positive pulse. I looked at the 555 timer, but...
View Articleabout hFE multimeter test...
Hi all... a transistor "BD435" is giving me 440 in hFE test on the multimeter, when the tecnical data i've found tell me min=40 max=475... does this mean the transistor is really in good shape? can it...
View ArticleWhat value pot?
My new digital FM tuner puts out too strong a signal compared to my other inputs (TV and CD). I want to install a dual pot between the tuner and preamp to reduce the volume. What is the best value pot...
View ArticleMains powered outdoor delay switch
Since pneumatic or mechanical delay switches with outdoor fitting kits are extortionately expensive, I was wondering if anyone had a good circuit for making my own... Ideally a single button press...
View ArticleHelp Building a USB-Controlled USB Outlet?
I am a novice and would like to build a 120V AC outlet which can be switched on and off by USB. I'm not sure what all I will need and want to make sure that I'm not trying to do something much harder...
View ArticleNeed current sensing relay
Hi folks, I'm looking for a relay I can put in series with a TV set to sense when it's on. The TV uses between 175 and 240 Watts, depending mostly on the backlight setting -- it's an LDC TV). So the...
View ArticleHow can I vary an Ultrasonic Mist Maker vibration using a soundcard tia sal2
Greetings All I would like to vary an ultrasonic mist maker like this one http://www.physlink.com//estore/cart/UltrasonicMistMaker.cfm using my audio sound card. Example: I want to produce complex...
View Articlefind mA rating for unknown power transformer?
I've got an old power transformer that is meant for a tube amplifier. It has 3 filament windings and one HT secondary. Running the primary direct from the wall supply, 120v, the HT secondary with out a...
View Articlecomputer sound card into Tens machine question
Greets All I'm trying to amplify my audio from my computer sound card and turn it into a Tens machine. So I need to increase the current/voltage do you guys know/recommend the best way to go about...
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