batteries

Started by kurt stocklmeir in sci.electronics.basics8 years ago 3 replies

I would like to know if all batteries that can be recharged get recharged at the same speed I am looking for a rechargeable battery that can...

I would like to know if all batteries that can be recharged get recharged at the same speed I am looking for a rechargeable battery that can get charge extreme fast thank you for any answers Kurt Stocklmeir -- --- Posted from http://lu7abf.org.ar/news --- news://freenews.netfront.net/ - complaints: news@netfront.net ---


driving a 1000 mW laser diode

Started by Ingmar Webb in sci.electronics.basics4 years ago 1 reply

I want to power a laser diode (the kind used for engraving) in a portable device for short periods with a 9V battery. The laser diode comes in a...

I want to power a laser diode (the kind used for engraving) in a portable device for short periods with a 9V battery. The laser diode comes in a tube with a focusing lens and trailing wires, and the spec says 5V 1A. This diagram seems to be the standard circuit for driving these. The LM317 spec says Vout is 1.25V above Va and it needs 3V of headroom. ---------- +9V----o-----...


Problem with Childs 12v 4x4 car - from an Electronics dummy!

Started by BobbyDazzler in sci.electronics.basics11 years ago 26 replies

I can test a circuit and check if there is powere on switches and cables but that tis the total knowledge of electronics I have :o( I was...

I can test a circuit and check if there is powere on switches and cables but that tis the total knowledge of electronics I have :o( I was given a childs 12v rideon 4x4 which wasn't working. If I switch it on and press the accelerator pedal (swtch) nothing happens. I have replaced the battery and can follow the current right through to the motors but nothing happens. I have wired the moto...


Failure mode of LEDs in overcurrent situation

Started by Andrew T. in sci.electronics.basics2 years ago 3 replies

I'm curious about what happens to an LED when it is exposed to a moderate overcurrent situation. This question came about as I was...

I'm curious about what happens to an LED when it is exposed to a moderate overcurrent situation. This question came about as I was troubleshooting some small white LED lights I built using 3 5mm LEDs and a current limiting resistor to run on 12Vdc (supplied by a lead-acid battery charged by solar). After some time, many of these strings would start to flicker or blink. I was about to po...


Truck Starter/solenoid/battery help

Started by amdx in sci.electronics.basics8 years ago 40 replies

> I'm having very intermittent lack of starter rotation on a Toyota > T-100. Over the last 14 years I have replaced the contacts in the ...

> I'm having very intermittent lack of starter rotation on a Toyota > T-100. Over the last 14 years I have replaced the contacts in the > solenoid and more recently (1 to 2 years) replaced the starter. > For trouble shooting I have a meter with one lead connected to the > bolt on the solenoid and the other to the frame. (solenoid is built into the starter) > The plan is; if


$0.79 Clip On LED Light for Phone Batteries

Started by Bret Cahill in sci.electronics.basics4 years ago

I have a collection of batteries I find cycling. Yesterday it was a Galaxy Note 4. You don't have to cycle thousands of km to find a mangled PDA...

I have a collection of batteries I find cycling. Yesterday it was a Galaxy Note 4. You don't have to cycle thousands of km to find a mangled PDA with the dislodged battery nearby. They leave the phone on the roof to load something into the car which requires both hands. The phone must absorb most of the 120 km/hr oblique impact because more often than not, the dinged battery is


A couple of simple questions about a simple op amp circuit

Started by Bob Engelhardt in sci.electronics.basics10 years ago 30 replies

I'm a new poster here. I've posted a couple of times to SED, but always felt that the general level of SED was _way_ above me. SE_Basics_ is...

I'm a new poster here. I've posted a couple of times to SED, but always felt that the general level of SED was _way_ above me. SE_Basics_ is more my level. My questions are about this battery tester (an "electronic load"): http://home.comcast.net/~bobengelhardt/eLoad.jpg 1. What is the purpose of R5? My guess is that the ckt would work without it, but it's in some way better with i...


Phone charger question

Started by Ivan Vegvary in sci.electronics.basics6 years ago 7 replies

Samsung Note 4 plus Google Nexus Tablet Have 3 wall chargers with USB port. Have only two cables that are USB micro. Always thought that...

Samsung Note 4 plus Google Nexus Tablet Have 3 wall chargers with USB port. Have only two cables that are USB micro. Always thought that one of my chargers is slow. NO! Turns out it is the cable. Battery monitor app (when it is on charge) suggests 2:15 (2h, 15m) to full charge with one cable and 5:21 (5h, 21m) with the other. The slow cable is a bit thinner. The above is t


Baffling simple circuit

Started by Bob Engelhardt in sci.electronics.basics5 years ago 15 replies

https://i.imgur.com/OWbZIrH.jpg The circuit monitors a battery & when its voltage is above an adjustable threshold, it closes a relay. When...

https://i.imgur.com/OWbZIrH.jpg The circuit monitors a battery & when its voltage is above an adjustable threshold, it closes a relay. When the voltage drops below the threshold, it turns off and latches off (the feedback diode). What's baffling is that it works for a second or 2 and turns off. Particularly baffling is when I measure the voltage at the arrow, it stays on. The voltm...


Even Tesla Missed This Low Hanging Fruit Calculation

Started by Bret Cahill in sci.electronics.basics4 years ago

> https://www.engadget.com/2018/03/22/tesla-says-underpaid-because-batteries-too-fast/ > > It looks like Tesla's batteries are too fast for...

> https://www.engadget.com/2018/03/22/tesla-says-underpaid-because-batteries-too-fast/ > > It looks like Tesla's batteries are too fast for their own good. As the Sydney > Morning Herald reports, the company claims it's not being properly paid for > the electricity its South Australia battery farm is generating for the > country's power grid. And Tesla says its because its batteries supply


FPGA power consumption

Started by Phil Hobbs in sci.electronics.basics10 years ago 1 reply

A client of mine is trying to build head mounted displays for the DARPA SCENICC program. http://tinyurl.com/6wygjlj It is of course...

A client of mine is trying to build head mounted displays for the DARPA SCENICC program. http://tinyurl.com/6wygjlj It is of course insanely ambitious--eye-resolution-limited imaging over the full visual field at 60 fps or so. It also has insanely ambitious SWaP (size, weight, and power) goals: 250 grams including battery, eyeglass or goggle form, power dissipation < 1W. To try t


Brushless three phase controller bypassed on full throttle?

Started by John Doe in sci.electronics.basics7 years ago 3 replies

As far as I know, bypassing the controller when using two power wires on a brushed cordless drill just means connecting the battery directly...

As far as I know, bypassing the controller when using two power wires on a brushed cordless drill just means connecting the battery directly to the motor through a physical switch built into the trigger. Is it likely that they bypass the controller when the trigger is fully depressed when using a brushless motor with a three-phase motor connection thingy? They have the standard warni...


Solar Panel Regulator

Started by BeeJ in sci.electronics.basics11 years ago 5 replies

Have several solar panels that I want to most efficiently parallel and regulate down to the following dc voltages/currents: Panel output is...

Have several solar panels that I want to most efficiently parallel and regulate down to the following dc voltages/currents: Panel output is 18VDC min full sun. 1) Output to charge a 12VDC car battery with overcharge protection and trickle / float charging capability. 2) 12 V 10 Amps regulate +/- 0.5v 3) 9 V 5 Amps regulate +/- 0.5v 4) 5 V 5 Amps regulate as USB output ...


oscillator with constant amplitude

Started by Tom Del Rosso in sci.electronics.basics7 years ago 19 replies

I don't want anybody to design it for me, but in general how would you make an oscillator with a sine output of constant amplitude over a range...

I don't want anybody to design it for me, but in general how would you make an oscillator with a sine output of constant amplitude over a range of supply voltage (let's say the operating range of the op-amp). What I have in mind is a battery supply, but with no power wasted in a regulator. Sure the oscillator would also waste power but not as much. Would a square output be simpler? ...


Battery drain question with an external car CD player

Started by super70s in sci.electronics.basics6 years ago 4 replies

I have just bought a used Sony Discman player to use in my car because the built-in one started rejecting CDs (older GM/Delco player, as...

I have just bought a used Sony Discman player to use in my car because the built-in one started rejecting CDs (older GM/Delco player, as they're wont to do). It has an adapter that you plug into the car's cassette player, then there's the 12V power adapter for the power. When I plug the power adapter into the power source (my car has a dedicated one, so I don't have to use the cigaret...


Boost DC-DC converter online simulation

Started by Patrick Chung in sci.electronics.basics8 years ago

Online simulation of Boost converter DC-DC converter is ready. Boost DC-DC converter has output voltage always higher then the input. This...

Online simulation of Boost converter DC-DC converter is ready. Boost DC-DC converter has output voltage always higher then the input. This makes it particularly useful in battery systems as well as power factor corrector circuits. Now it can be online simulated: http://www.cirvirlab.com/simulation/smps_boost_or_step_up_converter_online.php Read theory of operation: http://www.cirvi...


Current regulator

Started by nescafe in sci.electronics.basics10 years ago 40 replies

Hi. I need to create some kind of charger. The "charger" will be powered from dc source ( 1,5 AA battery ). The voltage should stay the same...

Hi. I need to create some kind of charger. The "charger" will be powered from dc source ( 1,5 AA battery ). The voltage should stay the same but the current should be regulated like this: - charge time: 1 day --> 1,5 / 50mA - charge time: 2 hours --> 1,5 / 100mA - charge time: 4 hours --> 1,5 / 200mA - charge time: 4 hours --> 1,5 / 500mA - charge time: 7 hours --> 1,5 / 1A ----------


mosfet bias question

Started by default in sci.electronics.basics4 years ago 3 replies

I plan to use a mosfet in a dawn to dusk switching circuit with a 12V regulated power supply. In the application notes they give the...

I plan to use a mosfet in a dawn to dusk switching circuit with a 12V regulated power supply. In the application notes they give the gate source absolute maximum voltage as +/- 10V Gate to Source. (page 1) On page 6 of the same application note they show a "Gate charge test circuit." with a 12 volt battery between the gate and source with a 50 Kohm variable resistor for the current source ...


Solar Charging Night Light not working

Started by Alberto in sci.electronics.basics2 years ago 24 replies

Hi all, I am trying to implement a very simple solar charged night garden light. Schematics is here:...

Hi all, I am trying to implement a very simple solar charged night garden light. Schematics is here: https://www.jameco.com/Jameco/workshop/JamecoFavorites/solarled.html Basically a solar panel charges a battery. When the solar panel output is low (at night), a joule thief circuit lights a led. The joule thief part works just fine, the problem is that the dark detector (2n3906 + 4.7K resis...


A timer device with relay

Started by Test in sci.electronics.basics5 years ago 11 replies

I've been looking for a low power and low cost timer device or info on how I could use to build one. I need to turn a relay on on a 5V device (a...

I've been looking for a low power and low cost timer device or info on how I could use to build one. I need to turn a relay on on a 5V device (a weather meter doing a number of other task as well). The weather meter uses too much amps for it to run on a battery. The low poer timer device would run on coin cell batteries and very hour or another predetermined time turn on a relay which would t...