Power supply wisdom

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The USB micro-B connectors were specifically designed for many insertion/removal cycles. They are a lot easier to use than the average cell phone power connector.

Barrel connectors are reliable and easy to use, but retention is flakey.

Mini-USB are pretty fragile too.. had to fix on one a Garmin nüvi 1490 GPS I lent out (replacement is a fairly fiddly task, but doesn't take long if you have the right tools).. and it looked pretty well supported by the plastic molding, not always possible with a low quantity product.

Micro-USB is supposed to be better.. especially life (number of insertions)-- it also has better retention force.

Lots of adapters have the USB-A female in them so you could use one of the old-fashioned USB-B connectors in the instrument with a USB-A to USB-B cable.

Sounds like faulty logic to me. EVERY new cell phone comes with a power supply. I'm all for standardization, but I can't see this regulation as keeping much out of the landfill. Until the regulation mandates the wall wart be a separate purchase, the number of wall warts sold won't change much.

Virtually every garage sale has a box of old cellphones. Virtually ALL of them have the connector so worn that it won't stay plugged in. Micro-USB is new enough that they're not showing up as much, but I'll bet that if you yanked on the cord at right angles, it wouldn't be very hard to break the plug or the socket.

My favorite is a barrel connector socket held in by a plastic feature in the case and wires that go to the circuit board so you can't fracture the solder connection by pulling on the socket. And if you use one of the smaller barrels, an accident is likely to break the plug first and be easier to fix. Certainly not the cheapest tho...

Over in Europe that's easier done than here. That is because phones are typically not locked into a provider and unless they have some fancy plan people buy the phones they want. They get activated by sliding in the provider's SIM card. So you could offer the phone at 10 Euros less if the charger option is declined. I don't know if that's going to happen though. Sometimes those Brussels bureaucrats come up with ideas that aren't all that well thought out.

(probably

value.

regulators

the

but

and

SEPIC

because

voltage

Shanghai"

It may not look like it but Micro-USB is a much better connector than the Mini-B. Expect Mini-Bs, and perhaps even Bs, to go away.

Having built both flyback and charge pumps, I find them both doable, but flyback is far easier to scale for delivering power. But my point is the diode bias doesn't need a lot of power.

A flying cap design of any sort (diode step up or charge pump) pings the battery, potentially causing noise. But a flyback radiates EMI, also a noise source.

When you get the chance, please explain your philosophy. In analog, often there is no perfect plan of attack.

The European Union mandated microusb as THE cellphone charging standard. You can't sell a phone in the EU unless it can be charged that way. [Personally I liked the miniusb. The microusb is a bit harder to see the polarity (key). ]

I'm already getting a collection of miniusb chargers as I acquire gadgets. But you can leave one in your suitcase, one in your car, etc. Because they are useful, they don't end up in landfills.

YOUR JOKING, RIGHT ??

You do not need to "see" it, you feel it:

On a sunny day (Tue, 10 Jul 2012 15:13:16 -0700) it happened mike wrote in :

It was not the reason. The reason is that now people need [to bring] only ONE adaptor [when travelling]. In the olddays you needed a sepatare suitcase for adaptors.

Yes, but now they all work on all cellphones here.

On a sunny day (Tue, 10 Jul 2012 15:46:34 -0700) it happened Joerg wrote in :

Most peoples phones here ARE locked, simlock. Only some die hard buy simlock free phones for more, like me. There is also a law that after 2 years (IIRC) they have to give you the unlock key. I unlocked 2 pre-pay phones that way after some years.

nlock key.

depends a lot on where you are I think, here the the carrier must unlock for free after a maximum of 6 months, want unlock before that they can charge ~70E in france I believe it is only 3 months

its a left over from when they more or less gave the phones away and you really paid the phone over the subscription

here they now generally do something like a cheap 2 year payment plan for the phone with a subscription more or less included

so even if you choose to move to a different carrier you still get to pay for the phone

-Lasse

key.

You can just take the locked phone to a dude in a kiosk and he unlocks it for a few rupees.

Best regards, Spehro Pefhany

On a sunny day (Wed, 11 Jul 2012 07:33:06 -0400) it happened Spehro Pefhany wrote in :

key.

I think they just made that illegal in my country.

unlock key.

OK, a few more rupees.

And a somewhat muscular guy gets it in either way. One guy even did that with a D-Sub, looked like bellows afterwards.

True, but he does it only once.

The microsimcard at the moment is a non-feature. I know a few iphone owners that have bought Android phones so that they can buy simcards in Europe for traveling.

My first GSM phone had a simcard the size of a freakin' credit card!

unlock key.

T-mobile...ya just ask them to unlock it. At least in the US. T-mob is number 4, so they can't afford to dick around the customer. They have you on a contract anyway, so they will get paid.

In any event, there are ways to get the unlock code if the carrier is not cooperating.

unlock key.

I managed to break my phone (an 8ft fall flat on the LCD) and was about to leave town, so I hit Craigslist. After a number of deals didn't go through, I eventually got a brand new phone from the Kiosk lady at half of new. Yeah, she unlocked it.