Lead Acid puzzle

Started by Tabby in sci.electronics.design2 years ago 34 replies

Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I'm not clear what's...

Cart with 2x 12v 33Ah progolf AGM lead acids. 1.5 years after fitting new batteries the available range is down to below 10%. I'm not clear what's gone wrong. The charger in use has been a cheap chinese one with 2x13.7v=27.4v output. Single stage charging only. It has always been promptly charged after use, and never run below 50% charge. I checked the battery voltages after charge, they wer...


Inverters vs wallwarts

Started by bob prohaska in sci.electronics.design5 months ago 55 replies

I'm setting up a UPS for my computer/comms equipment using an inverter/charger and battery from Amazon. The equipment draw is only about 40...

I'm setting up a UPS for my computer/comms equipment using an inverter/charger and battery from Amazon. The equipment draw is only about 40 watts measured with a Kill-A-Watt, but all the associated wallwarts use capacitive-input switching power supplies. That means they only draw current at line peaks. My seat-of-the-pants guess is that the duty cycle is around 10%, meaning that the aver...


Fun with EV to Vegas

Started by Ed Lee in sci.electronics.design4 weeks ago 14 replies

North bound at Mountain Pass is out. No problem, i'll drive pass the center media to the south bound charger. I wonder if that would damage my...

North bound at Mountain Pass is out. No problem, i'll drive pass the center media to the south bound charger. I wonder if that would damage my tires. OK, i'll bring the tire repair patch with me. https://www.plugshare.com/location/308971 Plugshare doesn't even know about the up-coming EA and Evgo stations at Primm. I wonder if they will let me tap into the high voltage transformer at the c...


USB charger circuit

Started by Anonymous in sci.electronics.design9 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 ...


Solar panel example for LT-Spice?

Started by Peabody in sci.electronics.design2 years 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...


Trans Sec Buttigieg calls EVs "generators"

Started by Flyguy in sci.electronics.design1 month ago 16 replies

https://www.cnsnews.com/article/national/susan-jones/buttigieg-electric-vehicles-could-be-very-useful-during-power-outage Of course, EVs don't...

https://www.cnsnews.com/article/national/susan-jones/buttigieg-electric-vehicles-could-be-very-useful-during-power-outage Of course, EVs don't "generate" anything, they are just a big battery. At best, they can be called a "reserve power source." Of course, once you have drained the EV's battery it won't MOVE. Using it as a power source means it must be connected to the charger whic


new 30MHz to 300MHz switcher - worlds smallest laptop adapter

Started by Jamie M in sci.electronics.design9 years ago 64 replies

Hi, Here's a new SMPS switcher apparently coming out next year for...

Hi, Here's a new SMPS switcher apparently coming out next year for laptops: http://phys.org/news/2013-12-circuit-laptop-charger-brick.html It apparently has a "power reclaiming scheme" for higher efficiency, would this be conventional sync rectification or some other thing? It looks like power electronics is in for a big (r)evolution once the 300MHz+ designs start to spread! cheer...


MC34063 Step-down Converter Heating Problem

Started by Anand P. Paralkar in sci.electronics.design11 years ago 21 replies

Hi, I have constructed a DC-DC step-down converter using the MC34063. The circuit I use is very similar to the one shown...

Hi, I have constructed a DC-DC step-down converter using the MC34063. The circuit I use is very similar to the one shown here: http://www.eleccircuit.com/wp-content/uploads/2008/01/ipod-mp3-player-charger-by-mc34063.jpg My circuit does not have the Zener, output side LED and input side protection diodes (TVS1 and D2 in the circuit). The rest of the circuit is quite similar. The...


Motion in support or reject EV charging chip reader?

Started by Ed Lee in sci.electronics.design1 year ago 90 replies

Again: "Cost - $700 million in costs could slow EV charger deployment across California. By CARB’s own calculation, an EMV chip reader...

Again: "Cost - $700 million in costs could slow EV charger deployment across California. By CARB’s own calculation, an EMV chip reader mandate will add approximately $3,000 to the cost of a charging station over its lifetime - $371 for the hardware and $270/year in operations and maintenance (O&M) costs" http://www.evassociation.org/carb.html For: 1. Allow simple an