Coil Circuit

Started by Anonymous in sci.electronics.design7 years ago 11 replies

Hi,=20 I am trying to make a wireless battery Charger. I made a coil ( primary coi= l) with following Specs 1. Number of turns :25 2. Wire...

Hi,=20 I am trying to make a wireless battery Charger. I made a coil ( primary coi= l) with following Specs 1. Number of turns :25 2. Wire Guage: 24AWG 3. Inductance : 426uH I added a series Capacitor with the coil. I am driving this LC series Circu= it with a Full H- Bridge driver ( HIP 4081A ) with four NMOSFETS. The power= supply is +12 Volts.=20 I am using Pulse Width Modultion...


Battery Charger

Started by Anonymous in sci.electronics.design8 years ago 32 replies

Hi, Need help with the following problem. What isolation should I use? ac to dc adapter ( 5v) -----> isolation -------> LTC...

Hi, Need help with the following problem. What isolation should I use? ac to dc adapter ( 5v) -----> isolation -------> LTC 4062 LTC Data sheet: http://cds.linear.com/docs/en/datasheet/4062fb.pdf AC to DC Adapter: http://www.digikey.com/product-detail/en/EMSA050120K-P5P-SZ/T1102-P5P-ND/2352095 melissa


Enough power ?

Started by Andy K in sci.electronics.design8 years ago 13 replies

I am looking to replace AAA batteries with this AGM battery. 4.5 AH- 6 VOLT It would power 3 flashlights that have 9 LEDS each that each use...

I am looking to replace AAA batteries with this AGM battery. 4.5 AH- 6 VOLT It would power 3 flashlights that have 9 LEDS each that each use 3 AAA batteries. I would also get a NOCO Genius 6v 12v 750 mA Wicked Smart Battery Charger G-750 for the battery. I also know that I will have to reduce the voltage. What do you think ? Andy


OT: electric car drama

Started by bitrex in sci.electronics.design6 years ago 60 replies

So there's a little shopping plaza down the street from me, with a Starbucks. A few weeks ago, the plaza management decided to install an EV...

So there's a little shopping plaza down the street from me, with a Starbucks. A few weeks ago, the plaza management decided to install an EV charger system outside the Starbucks apparently to bring in business for electric car owners. The machine charges a nominal fee per hour to charge there. Problem is, the parking in the lot is very tight, and in the morning it's crowded. They in...


Why chargers heat up

Started by Andy in sci.electronics.design4 years ago 2 replies

Why do chargers heat up? Nothing is 100% efficient. And I think your answer is "both". The processes of converting voltages and controlling...

Why do chargers heat up? Nothing is 100% efficient. And I think your answer is "both". The processes of converting voltages and controlling currents make the charger drop its efficiency and heat up. The heating is the product of power losses, which are I2R losses. That means the losses due to the resistance of the elements. Even a short wire has a resistance. However, most of


Can a small photocell panel be connected to a flashlight type rechargable battery?

Started by Anonymous in sci.electronics.design3 years ago 43 replies

I acquired a dead solar cellphone charger unit. I did minimal testing of it, and it was totally dead. It has the surface mount components, so...

I acquired a dead solar cellphone charger unit. I did minimal testing of it, and it was totally dead. It has the surface mount components, so I did not go any further. I salvaged the 2.5" X 4" solar cell panel, and tossed the rest of it. In a lighted room, (lights turned on) it puts out just under one volt DC. I imagine it will put out more voltage in sunlight, but I have not tried it, since ...


How is this IC powered?

Started by Bob Engelhardt in sci.electronics.design10 years ago 14 replies

I brought home a fence charger from the dump, hoping that it was there due to some simple malfunction that I could fix. On opening it up, I...

I brought home a fence charger from the dump, hoping that it was there due to some simple malfunction that I could fix. On opening it up, I found no blown fuse or other obvious problem. I found the circuitry interesting: it uses a 7-bit ripple counter IC to count 60 Hz pulses, with a 64-count triggering an SCR to dump a capacitor into a high-voltage xformer. I.e., the fence is pulsed ...


Power outlet on air planes and ground wire ?

Started by Skybuck Flying in sci.electronics.design8 years ago 20 replies

Hello, I was just wondering... since the plane is in the air... and maybe have power outlets ?! What happens with the ground wire ? Do...

Hello, I was just wondering... since the plane is in the air... and maybe have power outlets ?! What happens with the ground wire ? Do planes have ground ? Since there is no ground ? HUH ?! This posting in light of the chinese stewardess that got fried because of apple charger ?! ;) Bye, Skybuck.


Battery charger ??

Started by Dave, I can't do that in sci.electronics.design8 years ago 8 replies

Hi All, A few months back I bought a really nice hand held spotlight and last night= it crapped out on me. I put it on charge and this...

Hi All, A few months back I bought a really nice hand held spotlight and last night= it crapped out on me. I put it on charge and this morning it was still dea= d so I opened it up. A small 2.3AH, 6-volt sealed battery and a wall-wart c= harger with the prongs facing out of the back. A bit of a visual surprise. A bit of poking around and the wal-wart (6vdc 300ma) is a done for. I have = ...


USB charger circuit

Started by Anonymous in sci.electronics.design8 years ago 20 replies

I am working on a simple USB charging circuit. Normally, the 3.6V NiMH bat= tery is connected to the device via the NC contacts of a relay. ...

I am working on a simple USB charging circuit. Normally, the 3.6V NiMH bat= tery is connected to the device via the NC contacts of a relay. When conne= cted, a 5V relay switch the battery to charge via a diode. So, a fully char= ged battery is around 4.2V. As someone suggested, i will put a parallel R = & C to reduce the hold current of the relay.=20 Questions: 1. What is the minimum ...


OT: Science of dropping things

Started by bitrex in sci.electronics.design6 years ago 63 replies

I'm fairly clumsy, and I drop things on the floor a lot. What often happens is that I hear something small clatter to the floor, like a...

I'm fairly clumsy, and I drop things on the floor a lot. What often happens is that I hear something small clatter to the floor, like a screw, or key, or cell phone charger. I then think "Ah, this should be easy to find." Then I end up hunting around on my hands and knees with a flashlight for that screw I heard fall to the floor...and I never find it. You'd think if you heard it hit...


Bridge rectifier question

Started by bitrex in sci.electronics.design6 years ago 16 replies

Forgive me, my power supply topology-fu is a little rusty. Still mucking around with my junk box flash capacitor charger. So if I have a...

Forgive me, my power supply topology-fu is a little rusty. Still mucking around with my junk box flash capacitor charger. So if I have a surplus tranny with a 1:12 step up ratio that I'm feeding through a cap with a 10 volt P2P square wave with a +5 volt DC offset, that gives me +5/-5 into the tranny. 1:12 step up ratio plus bridge voltage doubler gives me about 120 volts out if I'm...


The last digital alarm clock?

Started by Anonymous in sci.electronics.design4 years ago 14 replies

My old digital alarm clock lost it's alarm last year (though the clock part still works fine) and I started looking for a replacement. I wasn't...

My old digital alarm clock lost it's alarm last year (though the clock part still works fine) and I started looking for a replacement. I wasn't looking hard because my smart-phone (Samsung Galaxy S4) could do the job if I moved it's charger into the bed-room. Everybody else seems to be relying on their smartphones too, because I couldn't find a digital alarm clock to buy in any of


Challenge of the Day: from halogen transformer to battery charger

Started by Anonymous in sci.electronics.design4 years ago 43 replies

It's silly challenge of the day time. I'm wondering if discarded halogen lamp SMPSU transformers could become car battery chargers. Thoughts so...

It's silly challenge of the day time. I'm wondering if discarded halogen lamp SMPSU transformers could become car battery chargers. Thoughts so far.... The main question is what can these units be counted on to protect themselves against. Overcurrent & short are the main questions. They will come across these IRL when driving halogens. How would they respond if the output were bridge rectifie...


Solar chargers, wondering about the output connector

Started by Sonnich Jensen in sci.electronics.design4 years ago 4 replies

Hi I have looked at designs of solar chargers, MPPT chargers etc. Nothing complicated there, but when I look at available chargers, I...

Hi I have looked at designs of solar chargers, MPPT chargers etc. Nothing complicated there, but when I look at available chargers, I wonder: It has a connector for the solar panel, and for the battery. Here I'd just consume from the battery? They have an output for consumption - have anybody taken them apart and can tell me why? I could see the use of a LC filter, as the charger wit...


Solar panel example for LT-Spice?

Started by Peabody in sci.electronics.design6 months ago 7 replies

I'm working on a TP4056-based 1S LIPO solar charger which includes a load sharing (aka power path) function. But I don't have a panel to test...

I'm working on a TP4056-based 1S LIPO solar charger which includes a load sharing (aka power path) function. But I don't have a panel to test with. So I'd like to simulate the circuit in LT-Spice. But I've never used spice, LT or otherwise, so I was hoping to find an example of a solar panel equivalent circuit that I could import, then add the rest of the circuit, which is pretty simpl...


Every day is a new learning experience :-)

Started by Andy K in sci.electronics.design8 years ago 2 replies

I bought a Hampton Bay Solar light in order to modify it to use as a battery charger in order to be more "Green Friendly" and to use it to charge...

I bought a Hampton Bay Solar light in order to modify it to use as a battery charger in order to be more "Green Friendly" and to use it to charge other batteries. It uses 2 lithium phosphate batteries rated at 3.2 volts 1000 Mah that powered the light. Battery voltage started at 1.3 volts and rose to 3.41 volts after about 36 hours of sun exposure. The product info said that it would last...


Using Batteries as a "Buffer" to Stabilize Grid Electricity

Started by Robert Miller in sci.electronics.design4 years ago 17 replies

A friend of mine lives in a remote area. The power grid voltage fluctuates causing problems with his equipment. He has tried line filters with...

A friend of mine lives in a remote area. The power grid voltage fluctuates causing problems with his equipment. He has tried line filters with no success. I suggested using a bank of SLA batteries as a "buffer". IOW a grid-connected charger would keep the batteries topped up and current could be redrawn via a 110V inverter to power appliances. In a nutshell, what would be the design...


Eternal Electricity

Started by Anonymous in sci.electronics.design6 years ago 75 replies

Would this work? I got this idea when one of my solar charged sidewalk lights ran out of power after a cloudy day. Normally that light lasts...

Would this work? I got this idea when one of my solar charged sidewalk lights ran out of power after a cloudy day. Normally that light lasts all night. I held a flashlight up to the solar cell charger panel, for a minute, and after turning off the flashlight, that solar light lit up for about a minute. So, lets say I take a LED flashlight, fill it with (fully charged) rechargable bat...


Cordless corded tools?

Started by John Doe in sci.electronics.design10 years ago 21 replies

I just converted a Dremel 10.8 V rotary tool to use Bosch 10.8 V batteries. I always have the rotary tool immediately in front of me, so the...

I just converted a Dremel 10.8 V rotary tool to use Bosch 10.8 V batteries. I always have the rotary tool immediately in front of me, so the battery will either be worn on a neck strap or be set down near the work. The wires coming from the rotary tool plug into the battery, using a socket taken from another Bosch tool. That was done because the rotary tool battery charger sucks. App...