typically stupid ED article

Started by Anonymous in sci.electronics.design2 years ago 77 replies

...

https://www.electronicdesign.com/technologies/test-measurement/whitepaper/21140081/warning-your- dmm-is-discharging-your-battery-cell?utm_source=EG+ED+Today&utm_medium=email&utm_campaign=CPS200 828010&o_eid=7322A4702401H9R&rdx.ident%5Bpull%5D=omeda%7C7322A4702401H9R&oly_enc_id=7322A4702401 H9R It's sad how bad the electronics press has become. -- John Larkin Highland Technol


Adapter fails to power DC motor

Started by Terry Pinnell in sci.electronics.design3 years ago 51 replies

I bought the following 4A 5V supply adapter:...

I bought the following 4A 5V supply adapter: https://cpc.farnell.com/stontronics/t6819st/ac-dc-power-supply-5v-4a-2-1mm/dp/PW04378?st=5v%20po wer%20adaptors with the aim of trying it as an alternative supply for my 16 year old curtain controller circuit. At present I successfully use 3 x AA Nimh batteries, delivering a voltage of about 3.8 to 4.1 V (measured at the battery terminals). Current


Triple Charging Gaps to Vegas

Started by Ed Lee in sci.electronics.design5 months ago 51 replies

I am bringing my Leaf to Vegas for someone to work on. Unfortunately, many mechanics refused to touch anything EV, even if only to drop the...

I am bringing my Leaf to Vegas for someone to work on. Unfortunately, many mechanics refused to touch anything EV, even if only to drop the battery down for me to work on. My Leaf currently have 15kWh, which is fine from the SF area to Bakersfield. However, there are three major charging gap in kWh. Mile gap is misleading. (1) and (3) are around 25 miles. (1) 20kWh: Baker to Valley Well R...


Running garden tools on 40-60V DC instead of 120VAC?

Started by Joerg in sci.electronics.design2 years ago 42 replies

I dread all those extension cords when using the hedge trimmer and other stuff. I found that if I connect the E-bike battery of a friend to it...

I dread all those extension cords when using the hedge trimmer and other stuff. I found that if I connect the E-bike battery of a friend to it the hedge trimmer runs somewhat slower but reliably. It had 53V DC. Those machines contain brush-type universal motors, probably with a compensation winding but not sure. Is is safe to run these with 40-60V DC over long periods of time or is ther...


Shady Dell laptop practices

Started by bitrex in sci.electronics.design5 years ago 41 replies

On some of the inexpensive Dell laptops they implement a hardware-lockout system intended to prevent you from using aftermarket charger bricks...

On some of the inexpensive Dell laptops they implement a hardware-lockout system intended to prevent you from using aftermarket charger bricks to charge the battery. The way they do this is there's a chip in the Dell charger that contains a unique identifier which a chip on the laptop mobo requests from it on startup over a one-wire interface. If on boot the BIOS can't confirm that the ...


Current Level Detection

Started by Cursitor Doom in sci.electronics.design1 year ago 110 replies

Gentlemen, I want to monitor current drawn from a car battery (12v lead-acid) in such a way as when it drops below 200mA, a piezzo buzzer...

Gentlemen, I want to monitor current drawn from a car battery (12v lead-acid) in such a way as when it drops below 200mA, a piezzo buzzer sounds. The range of current the monitor will see will run from 15A to around 75mA. The 15A will last for only around 10s or so and once it settles down will drop to 240mA for hours on end. This is just to monitor quiescent current drain and there will b...


CML-CML level shifter

Started by John Larkin in sci.electronics.design11 months ago 19 replies

I have a differential output from a fast CML flipflop, powered by +3 and ground, and want to drive another CML-input part. If the load gadget...

I have a differential output from a fast CML flipflop, powered by +3 and ground, and want to drive another CML-input part. If the load gadget was also powered from +3, I'd just connect them with a couple of 50 ohm traces. But the Vcc of the destination part could be anything from +3 to -2. I want full speed and DC coupling, so the ideal part to put in series with both runs is a battery ...


Sub uA battery powered current source.

Started by George Herold in sci.electronics.design5 years ago 20 replies

So I was out at UB, (picking up some stuff) I was talking with Bruce's* final grad student. He had some success biasing a resistive FIR...

So I was out at UB, (picking up some stuff) I was talking with Bruce's* final grad student. He had some success biasing a resistive FIR detector with a current source. The grey haired tech turned him onto an LM134. (A new IC for me too.) http://www.ti.com/lit/ds/symlink/lm134.pdf Apparently they are running it dry down at 1uA and either need more voltage or less current.** (Suppl...


not OT : fear

Started by John Larkin in sci.electronics.design3 months ago 143 replies

https://www.studyfinds.org/fear-for-safety-every-day/ What's wrong with kids these days? Most have been super-protected children but are...

https://www.studyfinds.org/fear-for-safety-every-day/ What's wrong with kids these days? Most have been super-protected children but are afraid of life. Engineers have to THINK, blow things up, take calculated risks. Fear warps prudent judgement. I've had interns that were afraid to touch a board powered from 5 volts, or handle a 12 volt battery. And wanted eye protection and masks ...


LED boost driver question

Started by bitrex in sci.electronics.design3 years ago 16 replies

There are a number of different inexpensive boost ICs of this style: for constant current driving LED strings from e.g. LiPo...

There are a number of different inexpensive boost ICs of this style: for constant current driving LED strings from e.g. LiPo battery. Any problem with chip of that type having say two strings of different color, perhaps white and blue, and switching between them using PNP or Pfet on the high side, with a common current-sense resistor?


Need a handheld enclosure for 16x2 LCD

Started by mpm in sci.electronics.design3 years ago 15 replies

Anybody know of a good source for handheld enclosures to fit a standard 16x2 line backlit LCD display? Preferably one that also has a 9-volt...

Anybody know of a good source for handheld enclosures to fit a standard 16x2 line backlit LCD display? Preferably one that also has a 9-volt battery compartment. Plastic is preferred. (Metal is also OK) And preferably one that comes complete with a bezel. This will be for a generic (temporary-use) handheld-type tester for something that runs on an RS-485 loop. So, a place to put QTY-(1...


Schottky diodes, reverse current and solar changers

Started by sonn...@gmail.com in sci.electronics.design2 months ago 13 replies

Hi all I am playing around with a solar lamp, pretty simple like this https://www.pinterest.com/pin/540150549038731182/ However I do not...

Hi all I am playing around with a solar lamp, pretty simple like this https://www.pinterest.com/pin/540150549038731182/ However I do not (yet) have D2. D1 in my case is a Schottky 1N5818, and my battery 7.2V I am surprised how much reverse current I can get through the diode. Without the solar cell, it does not turn on. There is enough current through D1 to the transistor to turn the wh...


Audio amp Mystery

Started by billbowden in sci.electronics.design6 years ago 10 replies

I have a little transistor radio that was drawing excessive power from the battery. It was about 125mA at 6 volts which is 10 times too much. I...

I have a little transistor radio that was drawing excessive power from the battery. It was about 125mA at 6 volts which is 10 times too much. I found I could bend the circuit board to eliminate the problem. So, I studied the thing for an hour or so and found the problem had something to do with the audio output transformer. This radio uses an input and output transformer in a push pull a...


Flyguy and fire-bombing.

Started by Anthony William Sloman in sci.electronics.design8 months ago 37 replies

Flyguy has this nasty habit of claiming that I want to fire bomb my own country. There was a thread about electric aircraft, and Flyguy came up...

Flyguy has this nasty habit of claiming that I want to fire bomb my own country. There was a thread about electric aircraft, and Flyguy came up with an accident report about an ultralight aircraft that had caught on fire. essentially because it's owner had abused the batteries. I suggested that it would make sense to dump an overheating battery pack before it caught on fire. Flyguy over-s...


Alternator problem

Started by linnix in sci.electronics.design5 years ago 142 replies

I know many engineers here work on cars, so ... I am debugging my wife's Lexus ES300. The problem is that the OEM alternators (original and...

I know many engineers here work on cars, so ... I am debugging my wife's Lexus ES300. The problem is that the OEM alternators (original and replacements) are not charging at idle. At idle speed, the alternator put out 8V to 10V, which is insufficient to charge the battery. At high speed, it does put out 14V. People suggested speeding it up by changing the front pulley (65mm) to a small...


cell phone / tablet USB host ?

Started by legg in sci.electronics.design10 months ago 26 replies

Recent experience (first) with a Lenovo Tab 8 had me scratching my head. It's USB (~charging) port could communicate with a PC for file...

Recent experience (first) with a Lenovo Tab 8 had me scratching my head. It's USB (~charging) port could communicate with a PC for file transfer, but couldn't read a memory stick. This with all the recommended OTG cabling. Why would you stick a communicative USB port on a battery-operated device and then restrict it from acting as a USB host? Is this normal? Is this sane? ...


OT: All cars electric..

Started by Robert Baer in sci.electronics.design3 years ago 179 replies

Hmmm . . . . Food for Thought Snow, Traffic Jams and Electric Cars - has anyone thought about it? If all cars were electric ... and...

Hmmm . . . . Food for Thought Snow, Traffic Jams and Electric Cars - has anyone thought about it? If all cars were electric ... and were caught up in a three hour traffic jam? With dead batteries - then what? Not to mention, that there is virtually no heating in an electric vehicle. And if you get stuck on the road all night, no battery, no heating ! You can try cal...


Why is an EV's backup power less than it's driving power?

Started by Commander Kinsey in sci.electronics.design4 days ago 198 replies

If an EV has an output power of say 80kW to drive the motors when driving, why is the backup power (to power your house in a power outage) only...

If an EV has an output power of say 80kW to drive the motors when driving, why is the backup power (to power your house in a power outage) only about 10kW? It's the same battery! And why do people say it costs thousands of dollars to fit something to do this? Surely a 10kW invertor doesn't cost much, just something to make 400VDC into 240VAC. I'd say more like 500 dollars.


RoHS and Lead Acid batteries

Started by Tim Wescott in sci.electronics.design8 years ago 17 replies

I'm working on a battery-powered bit of kit for a client. His old system was powered by lead-acid batteries, and while we don't feel a need to...

I'm working on a battery-powered bit of kit for a client. His old system was powered by lead-acid batteries, and while we don't feel a need to retain continuity for continuities sake, we should think before we step away from what's been done. Does anyone happen to know what the deal is with RoHS and lead-acid batteries? Do you get a pass on that, or is there some well-structured way...


Ultra-low power switching boost converter - in a DIP

Started by Peabody in sci.electronics.design6 years ago 24 replies

For a hobby project, I've found the perfect part for converting battery power to a very low current (2 ma at most) 28V power supply. And that...

For a hobby project, I've found the perfect part for converting battery power to a very low current (2 ma at most) 28V power supply. And that is the Linear Technologies LT8410-1 "Ultralow Power Boost Converter". The problem is that the only package available is a tiny surface mount chip that's 2 x 2 millimeters, which effectively makes it impossible to deal with using a soldering iron....