Search found 692 matches

by ConRAD
18 Oct 2020, 7:37am
Forum: Bikes & Bits – Technical section
Topic: Battery Charger not very clear OUTPUT spec
Replies: 13
Views: 385

Re: Battery Charger not very clear OUTPUT spec

... it makes sense to increase voltage, which can only be done following the IC negotiating a safe higher voltage with another IC in the device being charged, failing which it will default to 5V ... Well, that appears to be indeed the real conclusion. 1. To “negotiate” the voltage both the “giver” ...
by ConRAD
17 Oct 2020, 8:16pm
Forum: Bikes & Bits – Technical section
Topic: Battery Charger not very clear OUTPUT spec
Replies: 13
Views: 385

Re: Battery Charger not very clear OUTPUT spec

Isn't this pretty much the same as charging two batteries in series? With (hopefully) some kind of voltage balancing. I don’t think so, each individual cell has its own DNA. Charging two batteries in parallel with the same voltage assuming that each one of them takes the same current or two batteri...
by ConRAD
17 Oct 2020, 7:56pm
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

rjb wrote:... to get current to flow requires a potential difference so the charging voltage will be higher than the 5v usb spec otherwise charging would not occur.

.. ok, thank you.
by ConRAD
17 Oct 2020, 6:13pm
Forum: Bikes & Bits – Technical section
Topic: Battery Charger not very clear OUTPUT spec
Replies: 13
Views: 385

Re: Battery Charger not very clear OUTPUT spec

Hopefully things start to appear much clearer now. Indeed the two devices that I bought, the power charger and the battery pack, both implement Qualcomm QC 3.0 technology according to which the delivered higher power is managed via a “negotiated” higher voltage instead of a higher current, in this w...
by ConRAD
16 Oct 2020, 5:20am
Forum: Bikes & Bits – Technical section
Topic: Battery Charger not very clear OUTPUT spec
Replies: 13
Views: 385

Re: Battery Charger not very clear OUTPUT spec

IIRC USB C can be multi voltage so it can be used for things like laptop charging that wouldn't have been possible with older variants of USB. I presume it "negotiates" between the charger & device in some manner to serve up the right power requirements. Here below the specs of the Po...
by ConRAD
16 Oct 2020, 5:09am
Forum: Bikes & Bits – Technical section
Topic: Battery Charger not very clear OUTPUT spec
Replies: 13
Views: 385

Re: Battery Charger not very clear OUTPUT spec

thelawnet wrote:... anyway, without a chip telling it to do differently, it will default to 5V ...

That's my conclusion too.
by ConRAD
15 Oct 2020, 8:11pm
Forum: Bikes & Bits – Technical section
Topic: Battery Charger not very clear OUTPUT spec
Replies: 13
Views: 385

Re: Battery Charger not very clear OUTPUT spec

Jdsk wrote: … how is the output switched? …

There’s no output switching, everything seems to be automatic (!)
Jdsk wrote:… can you add a URL …

HER IT IS
thelawnet wrote:… it seems to be a usb power supply with quick charge 3 …

... probably that’s the case, but I don’t know how it works …
by ConRAD
15 Oct 2020, 6:48pm
Forum: Bikes & Bits – Technical section
Topic: Battery Charger not very clear OUTPUT spec
Replies: 13
Views: 385

Battery Charger not very clear OUTPUT spec

I bought a new battery charger that features the following OUTPUT spec:

DC 3.6-6.5V/3A, 6.5-9V/2A, 9-12V/1,5A

I tested it either connected to a resistive load and to charge via USB interface my mobile phone and in both the cases I’ve measured 5V … so what does the above spec mean?
by ConRAD
15 Oct 2020, 3:15pm
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

... you haven't given the specs so it's not clear if it will put out 12v or not ... ... apparently yes, here the specs: TECHNICAL SPECIFICATIONS Battery capacity: 20000mAh 74Wh Micro-USB input: DC 5V, 2A USB-C input: DC 5V, 3A - DC 9V, 2A USB output: DC 5V, 3A – DC 9V, 2A – DC 12V, 1.5A USB output:...
by ConRAD
14 Oct 2020, 3:39pm
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

... well it looks to be a mined field!!
however here below a test with a B&M Lumotec alternatively powered with 5Vdc and 6Vac, do you note significant differences?
NOTE: footage speed reduced to 50%

by ConRAD
14 Oct 2020, 1:19pm
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

Well, actually my 20000mAh/74Wh powerpack is going to stay inside the handlebar bag so IPXX is not an issue. It already comes with 2-off USB-3.0 output ports, 1-off USB_micro input port and 1-off USB-C input/output port personally tested at more than the declared 18W. Furthermore no cable/output por...
by ConRAD
14 Oct 2020, 11:30am
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

... lot of power banks might only put out 0.5A which is 2.5W ... Thank you. Modern power banks are however, in many cases, provided of multiple output ports (USB-2.0/3.0) and USB-C this last one capable to automatically adapt output voltage to the connected device up to 18W. The real problem for me...
by ConRAD
14 Oct 2020, 9:47am
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

rjb wrote:... I was considering using a simple bridge rectifier to run these lights from a dynamo ...

... sorry but a simple bridge alone doesn't make a 5Vdc stabilized output voltage !!!
by ConRAD
14 Oct 2020, 5:56am
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

... some will relish up to 9v... Indeed for testing purposes only I've already been checking for short whiles common AC dynamo lights with a 9V battery ... but what I'm looking for are nominal 5Vdc front and rear lights with no battery incorporated , perhaps anything like that? https://i.ebayimg.co...
by ConRAD
13 Oct 2020, 3:38pm
Forum: Bikes & Bits – Technical section
Topic: USB/5Vdc Front&Rear Lights
Replies: 16
Views: 463

Re: USB/5Vdc Front&Rear Lights

... and dynamo lights ... Dynamo lights are basically conceived and designed to work with AC. They definitely can work with DC either ... but this is NOT a good solution because in such a case only half of the 4-diodes bridge of the light would work, that causing useless overheating and efficiency ...