iPhone mount and power

[wm]

Have people seen this http://www.bikeradar.com/news/article/d ... ount-23264

It looks like a great bit of kit. I could put my phone on my bike and using the Reecharge cable keep it powered up from the hub dynamo. I can then use the phone for a GPS/mapping/tracking without the worry of it running our of power.

[Cavemud]

79 - 99 euros for the recharge device is insane.

I've been recharging my mobile phone from my dynamo for nearly three years now. A simplye DIY circuit with bridge rectifier, capacitor, and 4.5v voltage regulator can be knocked up in less than half an hour with a soldering iron. All for less than a fiver from your local maplins store. The only expensive bit is finding the correct adapter for your phone, but the easiest way to get around this is use a USB socket, then use a usb charger lead for the phone. The wiring of USB leads is well documented on the net.

Keep the circuit board long and thin and you'll be able to pop it down the seat tube or shove it up the headtube.

You can also consider using a 6v regulator also to power led front lights that take four aa batteries, and a 3v regulator for led rear lights (that take 2 aa/aaa's).

Also, most modern phones have the intelligent charge function built in to them, so all you need to do is provide the voltage and the phone does the rest (unlike batteries say, where a complicated charge sequence is required and hence a dedicated battery charger is required).

As for the bar mount, an aquapac and a few releasable zip ties is the best solution I've come up with.

[Kevin K]

I've been recharging my mobile phone from my dynamo for nearly three years now. A simplye DIY circuit with bridge rectifier, capacitor, and 4.5v voltage regulator can be knocked up in less than half an hour with a soldering iron. All for less than a fiver from your local maplins store. The only expensive bit is finding the correct adapter for your phone, but the easiest way to get around this is use a USB socket, then use a usb charger lead for the phone. The wiring of USB leads is well documented on the net.

Assuming one has the technical skills, of course.

[wm]

79 - 99 euros for the recharge device is insane.

I've been recharging my mobile phone from my dynamo for nearly three years now. A simplye DIY circuit with bridge rectifier, capacitor, and 4.5v voltage regulator can be knocked up in less than half an hour with a soldering iron. All for less than a fiver from your local maplins store. The only expensive bit is finding the correct adapter for your phone, but the easiest way to get around this is use a USB socket, then use a usb charger lead for the phone. The wiring of USB leads is well documented on the net.

Keep the circuit board long and thin and you'll be able to pop it down the seat tube or shove it up the headtube.

You can also consider using a 6v regulator also to power led front lights that take four aa batteries, and a 3v regulator for led rear lights (that take 2 aa/aaa's).

Also, most modern phones have the intelligent charge function built in to them, so all you need to do is provide the voltage and the phone does the rest (unlike batteries say, where a complicated charge sequence is required and hence a dedicated battery charger is required).

As for the bar mount, an aquapac and a few releasable zip ties is the best solution I've come up with.

I agree £74.99 (which they will retail for in SJS apparently) is a lot of money. Too much. I did read this persons website http://garote.bdmonkeys.net/bike_charger/ but I just don't have the skills. Mechanical items I can deal with electricity has never been one of my strong points. It seems the iPhone has some more complicated handshake thing going on which makes things a bit more tricky.

I am not interested in the battery just the charging kit. Are you interested in making one for me?

[[XAP]Bob]

As for the bar mount, an aquapac and a few releasable zip ties is the best solution I've come up with.

I use a "klick klick" food box from morrisons to hold my batteries and electronics on my rear pannier - works well, and the batteries are easily accessible when required (daily).
Never found a decent way to mount on the bars, so my front electronics (pair of current drivers) are in an old 35mm film pot slung under the top bar with copious quantities of 'leccy tape.

[Cavemud]

Aaaaaaaarrrrggghhhh

I just spent half an hour posting the charge circuit, only to hit submit and get 'authentication error' and loose all my work!!!

[wm]

Oh no, I appreciate your effort, just hope it makes sense.

[Cavemud]

OK, here’s my post again but this time done in word so the forum can’t eat it:

It’s really a very simple circuit to construct. About as simple as it gets.

I’ve attached a PDF of the circuit (assuming that works) with a few labels on.

I’ve labelled solder connections as either +, - or a little wavy symbol to represent ac input. Note, it doesn’t matter which way round you connect your dynamo as its ac current. Oh, and this is assuming you connect the wires directly to the dynamo, not via any switching unit supplied by the manufacturer. My shimano nexus came with a switching unit which regulated to 6v, I promply threw this in the bin!!

All you need in addition to a soldering iron and some solder is:

- Bridge Rectifier (Maplins code AQ98G £0.44)
- Capacitor (Maplins Code VH54J £0.80) – the capacitor size is a bit of an approximation that I found by trial and error, as strictly speaking it depends on the speed you are cycling at….
- Voltage Regulator (Maplins Code UJ54J £0.91) Actually a 5v regulator but your phone is really not that sensitive, it will most likely accept any input up to 25v)
- Breadboard (Maplins Code JP53H £2.62)
- Wire, to make connections from the board to the dynamo/unit.

To connect to the device, I personally cut up a charge lead and wired that in, but you also have the option to use a USB socket (maplins code L51AZ £1.39) and then use any USB charger you like.

You also have the option to put a switch on either the input or output side to disconnect the unit when not in use.

Personally I use (the more complicated version of the) circuit to charge my N95 phone and my Satmap GPS (sshhh though, don’t tell Satmap or they’ll void my warranty!!)0

There you go, a little project for less than a tenner that will charge all your gizmo’s on tour from your dynamo.

[Cavemud]

Grrrrr

Why aren't I allowed to attach a PDF??

[wm]

I have sent you a pm with my email address for that pdf. Sounds buildable based on what you have said.

I think a diagram would be very helpful though.

What did you use as casing?

I am using a Shimano hub without a switch. Could I run lights and charge at the same time if connected in parallel?

[[XAP]Bob]

PM me if you want it hosted...

[meic]

-" Capacitor (Maplins Code VH54J £0.80) – the capacitor size is a bit of an approximation that I found by trial and error, as strictly speaking it depends on the speed you are cycling at…."

I am pretty ignorant of the electronics theories behind your circuitry but would it be harmful if the bike speed was to go up to 40mph for a minute or two. Or is it to get some optimum level of charging for the dynamo rpm.

[Cavemud]

Nope, it just doesn't work as well at slower speeds.

For example, on my circuit (which powers my lights), when I slow down to the traffic lights the lights start to flicker on and off when I reach walking pace.

The effect on a phone charger would be the same as switching the charger on 10 times a second, however in reality the phone ignores this phase and only really kicks in when above 10mph say

[wm]

I think I am right in saying that the circuit you have described to me does not incorporate this

Sounds like a good idea. But for iPhone users, there's a catch.

There are only two ways to get an iPhone to charge. You either hook it up to a USB hub that's connected to a computer, or you hook it up to a charger specially designed for the iPhone.

In the case of a computer, the iPhone does some auto-negotiation over the data lines of the USB connection to ratchet its power up to 1/2 amp. The auto-negotiation is what lets the iPhone know that it's okay to charge. If it can't auto-negotiate, it will sit there and do nothing.

In the case of a special iPhone charger, a circuit inside the charger supplies the USB data lines with two specific voltages, which the iPhone is able to sense. These voltages are a kind of signature that tell the iPhone it is connected to a charger, and that it is OK to charge and draw 1 full amp of power.

Does Apple do this in order to exclude certain chargers so that you'll have to pay more to buy theirs?
Stalwart geeks out on the internet have disassembled an iPhone power brick, and exposed the circuits that generate the special voltage. Turns out the secret is a grid of four resistors. So if you want to charge an iPhone, you need to supply 5 volts on the power line of a USB connector just like you'd expect, but you also need to get four resistors and wire them up between the data lines, the power line, and the ground wire so that you're supplying 2 volts and 2.7 volts on the data lines. (Apparently this sort of circuit is called a "voltage cascade".)

taken from the website I put a link to in the first post.

You also said the capacitor choice was related to speed and you had determined it by trial and error, but you didn't say what size you went for.

[mark_w]

I've been waiting for them to release this for a while, but in my impatience I actually went out and bought an Edge 305 off Ebay.

I do like the iPhone but having used the TomTom app in the car, I fear the GPS sensitivity is nowhere near as good as the Garmin device.

But my big question would be - how waterproof is this? I know it's meant to be water-resistant, but is it as waterproof as an otterbox, for example?

Currently if my iPhone comes with me for a ride, it lives inside a Haglofs Watatait Case in one of my pockets - as even if I have my waterproof jacket on, it gets wet from sweat. And Apple being Apple, they've put little litmus papers inside the phone and in some of the connectors so they know if your phone's been damp or wet.