Testing a NST with a DMM?

I have been looking for a good (and cheap) NST for a while but i dont want to risk spending too much on a NST that doesnt work. I know that my local scrap yard has a large supply of old NSTs that are either there because both or one side doesnt work, they were upgraded, or someone needed the money and/or space. i also know that they would frown upon me wiring each one up and testing each. so onto the real question: is there a way to test a NST with just a multimeter and possibly a battery (i know thats how some people test for flyback transformer pins) or if checking continuity would be enough or even another way? Just so everyone knows i have spent quite a while searching for someone using this technique but didnt find anything, also im looking for a way to know for sure if one or both sides are working.

Question by pmk222 3 years ago  |  last reply 3 years ago


Dmm model no. MAS830L not accurate

I bought multi meter on line recently. But it I think cannot measure electronic component accurately. Specification as below 1.model no. MAS830L 2.Brand.MASTECH I measure new battery of 9 V with thus multi meter. But reading is 10.76 V which not correct. So what can I do with this dmm.? 0r how can we calibrate it.

Question by SangpoSangpo 3 months ago  |  last reply 3 months ago


How do I use this Test Function on a DMM?

 My DMM has a function for a 20mA loopback circuit. It rates 4mA at 5% and 20mA at 100% So what would I use this test function for?  Instead of using  the Amps test function?

Question by ricoplace 9 years ago  |  last reply 9 years ago


Step up 6 volts to 9 volts? Halp!

I have a GB Instruments dmm i got at a Hamfest (Ham Radio Fest) in Peoria, IL a few years back for like $6. It's great, and its more accurate than my father's Craftsman from Sears that he paid $40 for about a year ago. I have replaced the 9 volt battery twice in it. 9 volt batteries are horrible for capacity, and I use this DMM so much it's almost a high drain on the 9v. I know that a standard 9v holds 500-700mAh. I have a whole box of old AAA batteries that have about 1.4+ volts still in them from a stupid car toy that drained an AAA .1v-.2v and called it dead. A standard AAA alkaline battery (E92 or equivalent) holds 1,200 mAh or 1.2Ah@1.5v. 4 alkaline AAA batteries holds 4,800 mAh@6v. I can fit 4 AAA batteries in the 9 volt holder in my DMM snugly with a piece of foam for anti-rattle. That's only 6 volts. The DMM will power on very dimly at 6v, so is there any circuit to make up for the lost 3 volts without adding a bulky power pack? There is a LOT of room in the DMM for mods n stuff. Thanks for any help Is there any way to step up

Question by lilpepsikraker 9 years ago  |  last reply 9 years ago


12V DC Motor Wind Turbine

Hi im trying to build a wind turbine.The purpose of the wind turbine is to determine the maximum amount of power it can produce with different loads. It needs to produce at least two watts of power during testing, I tried using a potentiometer but it started smoking. I need to record voltage, current and power. I needed to know how to set this up, and if I can use resistors instead of a potentiometer. I have power supplydmmresistorsblade12V DCWires

Question by hj212121 20 days ago  |  last reply 19 days ago


can some one tell what is the voltage (ac and dc both )In a phone line? Answered

I have a DMM but it is of low quality so i assume may be my readings were wrong ... i found out to be 50V DC (when knob was at DC) and a Vrms of 110V when i turned my DMM's knob to AC ... even when the phone was not ringing is my method of finding the voltage right? can someone check what is the actual voltage in a phone line part 2 if the voltage is 50v Dc then when i connect a resistor it is lowered to 16V and if the resistor is 240 ohm then it is more lowered to 8V  what possibly the reason could be ? and when an led is attached directly to 50V it glows BUT theoretically it should Blow up. any idea whats going on ?

Question by usbg3rd 7 years ago  |  last reply 2 years ago


Autorange Brymen BM511?

I have an unusual problem. My BM511 will not auto-range and readings on VDC are odd. A 1.5v battery initially shows OL, then 00.61, 001.5 then 0002V as you manually step up through the range of the meter using the 'range' button. I suspect it has been burnt, either the input protection, bridge or scale divider. As I do not have a diagram i cannot fault find. Does anyone have a circuit diagram for the Brymen BM511 DMM. Thanks in advance. Regards, KH

Question by KeithH65 2 years ago  |  last reply 2 years ago


Cheap Auto Range Multimeter? Answered

As the question states. Anyone know of a good, cheap, auto range DMM? The more features and higher ranges the better. I don't need true RMS, would like capacitance checking ability as I reuse a lot of used electronic components from stuff people throw away, and I always saw auto range as more of a convenience, not a necessity. I would like to spend as little as possible, as I'm sure I'll eventually burn it out on one of those used components, like I did the $20 harbor freight clamp meter I had.

Question by Dochide 7 years ago  |  last reply 7 years ago


Steppers and EMF.? Answered

I have build this Bi-Polar stepper circuit and it works great on the bread board. I etch a board 3 times, 2 with heat transfer and 1 with photo resist. I use 2 completely separate power supplies but with the PCB's i think i am experiencing EMF or feed back. I am using an adjustable schmidt trigger for the clock. What happens is i can hardly get any rpm's, sometimes if the trigger is set just wright it will turn up fairly well, at that time if i try full step the stepper stops turning or will reverse sometimes, if i try ccw it may or may nor reverse and i may stay in what ever direction and any given time . Now at a slow rpm full step normally work's and cw/ccw may or may not work, also it can trigger the half or full step. Also i can disconnect one coil and the stepper will continue to turn, If i try that with the other coil the stepper will stop. So it looks like it is only running on one coil. Is that possible? Keep in mind i have bread boarded it and work's fine. Its just on the 3 pcb's that all this happens. As for the diodes it seams to work better with 1N4001's than 1N4148's I have checked every trace with an DMM and made sure they are going to the correct pins ect. I have tried different IC's L297 and L298 and steppers 2 different kinds and multiples of each. So i am thinking this is EMF, feedback, or a design problem. I have tried to eliminate most every thing i can think of. Comments?     

Question by WWC 7 years ago  |  last reply 6 years ago


Please help me restore this old Lead acid battery

Hello everyone, I just salvaged a small, 50AH FLA battery from a Tractor. The Battery has seen 2~3 calendar years. It was showing 11.38 Volts sitting on the shelf since 3 months so I thought it was good and I brought it for a bargain. I brought it home and connected it to my Intelligent charger which claims to support (Automatic)- Deep discharge Charging Boost Charging Absorbtion Charge Tricke Charge Equization Charge Automatic Charge Current and voltage regulation with Temperature compensated charging. The charger is currently showing "Boost charge" at about 12 Amperes. Problem is,the Charging voltage seems to Jump from 13.1v all the way to 14.2V (like under 10 sec) I hooked my DMM to the battery terminals which comfirmed the same. Sometimes the voltage also reaches 14.4v and the Charger goes into "Equalization Charge" but falls back to Boost charge at 13.5v or something odd. After 3 days for 'Cycling" I tried a eq charge twice. it seems to be improving. the Battery voltage on charge is still jumping across 13.6v to 14.2v. if I draw a load it goes back to 12.3v. admirably, I connected the Battery to our DC load yesterday night and it ran Led street lights (load 4a ) for 5 hours before I switched it off. 20AH is decent progress for 50ah old Battery right? do you think it's sulpahation that's causing voltage jump? I ran the Battery down to 11.5v yesterday. in the morning with sun up, the Battery is slowly progressing from 12.8v and above... very stably. the charger shows'absorbtion charge' at 8-9 amps. 8 amps are good for 50ah Battery right? else how do we test the ah of Battery?

Topic by bhvm 4 years ago  |  last reply 4 years ago


Robot Ascii Art

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Topic by Arbitror 9 years ago  |  last reply 9 years ago


Crowdfunding

We love seeing our authors transform their ideas into a reality, and we want to help in whatever ways we can. Below are some of the campaigns our authors are working to get funded. We'll do our best to keep this list current, so please check out their projects, and help fellow makers in our community find success!  Current Campaigns i-mimic the animation made easy, Device capturing human motion directly in 3D animation software in real-time & without plugins. by Instructabler nawres102 Open Source DIY Automatic Tail Light, A fun and easy to assemble light sensor kit.  By Instructabler Solarcycle Tiq probe, it defines a new category of electronic debug & test tools for makers & professionals - filling the gap between DMMs & 'scopes. By Instructabler markhen57 If you have a project you're trying to get funded, let us know!  Completed Campaigns  Doughnut Safe, Turn your spare tire into a strong box.  By Instructabler Mrballeng The fumeFan, The fume Fan is a soldering fume extractor, work lamp, helping hands tool and a project organiser for hobbyists, makers and creators.  By Instructabler hertzgamma SOLARPAD Open Source 5 Watt Smart Phone Solar USB Charger, Strap this water-resistant solar panel and battery to backpacks or mount it to tripods for camping, hiking, and cycling.  By Instructabler Solarcycle Fish Bone, A no knots cord tightener specifically designed for paracord by author Mrballeng - Funded by almost 9000% of goal! Would you Woodwork, a funny and informational woodworking webseries by author Few Bits - Funded by 100% of goal!  Zero to Maker, a re-skilling guide for new makers by David Lang - Funded by almost 2000% of goal! Arabic Alphabet Fun Flashcards, cute and kid friendly learning tool by author acraftyarab - Funded and met goal! PIXEL: Interactive LED Art, an interactive LED-based display for retro pixel art by author alinke - Funded by over 600% of goal! Blinky Fish, a tiny fish-shaped board that fits on an Arduino to help teach, by author marc.cryan - Funded by almost 600% of goal! Chipper, the ATtiny Programming and Prototyping Shield, by author Hammock Boy - funded by over 1000% of goal! Piranha, a follow-up knotless gear tie for paracord, by author Mrballeng - funded by over 1400% of goal! The Question Block Lamp, a Mario-inspired, interactive lamp for your inner geek, gamer and child, by author bduxbury - funded by almost 150% of goal! Out of Time - A patina weathered I-Beam with moving gears by Instructabler hack818 Maker Kase - Universal Maker cabinet. Perfect for 3D printers, model makers, small CNC machines and open frame Bitcoin Miners by Instructabler bmc.loughlin Have you started your own Kickstarter or Indiegogo to help fund your project? Let us know! Please leave the link in the comments, along with a brief description. We'll add your project to our up-to-date campaign list above, and promote it across our channels. If you have any questions, or want to add any additional info, please email me at khoward@instructables.com Thanks!

Topic by kazmataz 5 years ago  |  last reply 7 months ago


Electrical / Electronics Engineering Position in Chicago - RAW THRILLS

Hi everyone, We have one of the ultimate electronics positions available. We make coin-op arcade games and constantly innovate our electronics to differentiate our games from the home consoles. We're looking for someone that can hack innovative technology and make it work in our market. Official job posting is below. Please check out www.rawthrills.com for more information about our company! JOB INQUIRIES SHOULD BE SENT TO jobs@rawthrills.com. Please include a resume and an explanation of your qualifications and interest. ====================================== Available Position: Highly Motivated, Entry Level Electrical or Computer Engineer Raw Thrills, Inc. - February 2010 Raw Thrills, the leading US manufacturer of coin-operated video games, is looking for an enthusiastic Electrical or Computer engineer to join our Electronics Engineering design team. You will be working as an efficient member of a small team on products that continue to gain domestic and international market-share. Immediately, you will contribute to the design and verification of electronics, firmware, and software. In addition to the internal team, you will work with partner engineering companies to develop & maintain products, and interact with contract manufacturers to troubleshoot issues on-the-fly as they arise on the production line. You will collaborate with several experienced engineers and programmers, all the while working independently most of the work day. At Raw Thrills, our arcade games are designed entirely in-house, from the ground up. They are composed of custom mechanical parts (wood cabinet, plastics, metals, etc.), an off-the-shelf PC, a monitor, custom wiring, custom electronics & interface devices, and custom game software. As part of the Electronics Engineering team, you will be involved in much of the arcade game’s design, from low-level circuitry to high level software, and everything in between: * ESD testing & EM compliance * Custom circuit & firmware design * System integration & validation (peripherals ↔ PC ↔ API ↔ software) * Operating System (Windows Embedded) maintenance * Device driver & device-application interface (API) programming * Device functional & longevity test design (including GUI PC software, firmware, and mechanical construction) * Coordination between mechanical and electronics design * and more! Required Skills: * Demonstrable working knowledge of C/C++: need examples of work and debugging proficiency * Solid understanding of digital circuit design & troubleshooting digital systems (from circuit to PC software) * Experience designing & implementing a digital system from the ground up (school project, internship, etc.) * FPGA (VHDL or Verilog) and/or MCU (c or asm) programming competency * Self-sufficient and motivated to independently learn * Proficient with standard bench tools: soldering iron, oscilloscope, DMM, etc. Bonus Skills: * Programming experience with PC↔device communication: USB, RS232, LPT, etc. * Schematic capture and PCB layout experience * GUI programming experience (Win32 or Linux) * Active knowledge of Linux / home Linux user * Working knowledge of common scripting languages (Python, bash, Windows batch, etc.) Example Projects: * Design low-cost circuitry to robustly control addressable LEDs for eye-popping lighting effects * Design, implement, and perform game system latency testing (create hardware/software as needed) o EX: What is the round trip time from button-press to in-game feedback? Where are the bottlenecks? * Design hardware diagnostic software to allow automatic system diagnosis by end-user * Design automated functional test software for completed PCB assemblies * Design circuit and layout PCB for contact-less sensor module o Determine and perform validation testing * Add interface firmware features (i2c, Dallas 1-Wire, etc.) to MCU based board and update PC API so that game programmers can leverage the new features

Topic by rawthrills 8 years ago