Schottky diodes, reverse current and solar changers

Started by sonn...@gmail.com in sci.electronics.design4 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.design10 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.design12 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.design2 months ago 204 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...


For U.S. Companies, the Race for the New EV Battery Is On

Started by Fred Bloggs in sci.electronics.design2 months ago

The U.S. has offered a $7,500 tax credit to buyers of most new EVs since the end of 2009; but starting in 2023, the IRA ties that tax credit to...

The U.S. has offered a $7,500 tax credit to buyers of most new EVs since the end of 2009; but starting in 2023, the IRA ties that tax credit to certain requirements for sourcing of critical minerals and manufacturing of batteries. By 2029, only EVs with 80 percent of their minerals sourced within the U.S. or its allied nations and 100 percent North American-manufactured or -assemble


DOE : Holiday Gifts for Energy Efficiency

Started by Fred Bloggs in sci.electronics.design2 months ago 15 replies

Didn't know there was such a thing as a fuel cell phone charger: "Some of the newest portable charging devices also run on hydrogen using...

Didn't know there was such a thing as a fuel cell phone charger: "Some of the newest portable charging devices also run on hydrogen using miniature fuel cells. These nifty devices use special cartridges that react with the air or H20, right from your own water bottle, to produce electric current. Prices are a bit steeper than a battery-assisted charger, but the hydrogen fuel aspect


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....


A battery powered jacobs ladder - schematic included

Started by Diesel in sci.electronics.design3 years ago 3 replies

https://www.youtube.com/watch?v=Uh_Df8tsH4M Jacobs ladder and the effects of frequency and duty cycle with...

https://www.youtube.com/watch?v=Uh_Df8tsH4M Jacobs ladder and the effects of frequency and duty cycle with DC. https://www.youtube.com/watch?v=Ll8guReWvFQ Jacobs ladder in the dark -- Survival is triumph enough. - Harry Crews


Long-lasting battery

Started by Piotr Wyderski in sci.electronics.design3 years ago 35 replies

This website: http://www.tadiranbat.com/ boldly claims "THE ONLY LITHIUM BATTERIES PROVEN TO LAST 40 YEARS" But when I click on the XOL...

This website: http://www.tadiranbat.com/ boldly claims "THE ONLY LITHIUM BATTERIES PROVEN TO LAST 40 YEARS" But when I click on the XOL line link: http://www.tadiranbat.com/long-life-xol.html and open a random datasheet, the time axis universally ends at 1e5 hours, that is only 11 years. How did they come up with the claimed endurance? Best regards, Piotr


Watch out for the latest Windows update if you use an older machine

Started by bitrex in sci.electronics.design2 months ago 3 replies

Seems to really hate some Sandy Bridge/Ivy Bridge machines, I use a Fujitsu Lifebook which has some nice features like a VGA output...

Seems to really hate some Sandy Bridge/Ivy Bridge machines, I use a Fujitsu Lifebook which has some nice features like a VGA output (for connecting to older projectors) and easily-replaceable battery and


Electric blankets, Gratuitous complexity??

Started by Existential Angst in sci.electronics.design10 years ago 107 replies

OK..... So ahm happier'n'a alcoholic workin the night shift in a Jack Daniels distillery.... with my 400# deep cycle battery, 1500 W...

OK..... So ahm happier'n'a alcoholic workin the night shift in a Jack Daniels distillery.... with my 400# deep cycle battery, 1500 W inverter (sitting in the back seat of m'truck), and my brand new blue electric blankey-poo..... Now I can curl up in a fetal position -- in m'truck -- in compleat toasty comfort..... Now, don't ax me WHY I gotta curl up in a fetal position -- in m'tr...


1, 2 , 3

Started by Jan Panteltje in sci.electronics.design9 years ago 18 replies

And maybe you think software is difficult. It was also difficult ot fit this all in this solar flashlight box. The parts: ...

And maybe you think software is difficult. It was also difficult ot fit this all in this solar flashlight box. The parts: http://panteltje.com/pub/1_2_3_part_1_IMG_4342.JPG Battery, GPS, SDcard, OLED, GMtube, Speaker, Flashlight LEDs... HV transformer is on backside 'PCB'. Better view of HV transformer, things coming together: http://panteltje.com/pub/1_2_3_part_2_IMG_4344.JPG ...


Tonghui TH2821A LCR Meter

Started by Mike in sci.electronics.design11 years ago 102 replies

Here's something that may interest some folks here. I just got my new Tonghui TH2821A LCR Meter, and I'm starting to become quite impressed....

Here's something that may interest some folks here. I just got my new Tonghui TH2821A LCR Meter, and I'm starting to become quite impressed. After some screwups due to a discharged internal battery and not reading the instructions, it is starting to give some really impressive results. 5 digits resolution on 1000uf caps, 4 digits on iron-core inductor, miscellaneous resolution on 30k...


Bolt battery problem

Started by Ed Lee in sci.electronics.design2 years ago 76 replies

GM advices not to charge more than 90%, and discharge less than 70 miles. So, effective range of 60 miles? Not much more than my 50 miles Leaf. ...

GM advices not to charge more than 90%, and discharge less than 70 miles. So, effective range of 60 miles? Not much more than my 50 miles Leaf. At least, Leaf batteries don't catch on fire. Leaf batteries are inefficient but over-engineered. https://www.cnbc.com/2021/07/23/gm-issues-second-recall-of-chevy-bolt-evs-after-vehicles-catch-f ire.html


Sloppy sine wave

Started by bitrex in sci.electronics.design7 years ago 5 replies

This is an about -30 dBu sine wave being amplified to about 0dBu by the triode section of a Sylvania 12EC8 triode/pentode "space charge" tube....

This is an about -30 dBu sine wave being amplified to about 0dBu by the triode section of a Sylvania 12EC8 triode/pentode "space charge" tube. The plate load is a single transistor gyrator/constant current source. Plate and heater currents are being supplied by a "China Special" boost converter module that's stepping up a 4 "C" cell battery pack. http://tinyurl.com/zeegduc Yick. Lots...


So, you are thinking about buying an electric truck...

Started by Flyguy in sci.electronics.design1 month ago 65 replies

...well, THINK AGAIN! Electric trucks are great for a run to the dump, but not much else. First, the weight of the battery is 3,000 lb! This is...

...well, THINK AGAIN! Electric trucks are great for a run to the dump, but not much else. First, the weight of the battery is 3,000 lb! This is dead weight that SUBTRACTS from the tow capacity and brings the Hummer's weight up to a massive 9,400 lb. This limits the Hummer's tow capacity to 7,000 lb, not very much when you are looking at super-duty trucks. The Hummer sports an impres