Looking for somone to build a small electronic circuit

uk-tyler

Fifer wrote: »

There is this, (no links allowed) which might be worth considering. (Out of stock at Play.com unfortunately - you might find it elsewhere).

I had seen those thanks, but a USB one would give me more flexibility. I have a USB to Nokia charger cable already, and phone upgrades would be easier. I have found a schematic online for what I need, but can't post links yet.

I might have to try my local college, see if I can persude an electronics student to make me one as a project, or cash in hand homework.

fwor

Worth trying again to post a link with spaces in so MSE's bot doesn't recognise it as one.

If it's simple enough, someone here would probably make up the PCB - especially if you would be willing to build a box for it yourself.

uk-tyler

fwor wrote: »

Worth trying again to post a link with spaces in so MSE's bot doesn't recognise it as one.

If it's simple enough, someone here would probably make up the PCB - especially if you would be willing to build a box for it yourself.

The circuit looks simple enough, but what do I know? I'm electronically illiterate:rotfl:.

www. (dot) arenddeboer (dot) com/bike-mounted-usb-charger/

I'm happy to build a box to house it in and pay for the services of someone to build it for me. However I'd like an expert opinion of whether the circuit is good enough for my needs.

Ideally I'm looking for an output of 5V 500mA at the USB from a 6V 3W input. A switch to allow me to use it to power lights when not using the USB would be a bonus.

fwor

Yes, it's simple enough. A shame he doesn't show the underside of the board, as it would save time having to design that - though in truth on veroboard it wouldn't be complex.

I'd guess the parts should be around £8, but it's the cost of someone's time that is likely to be a bigger factor.

uk-tyler

Like I said, the cost of a decent soldering iron and melted components trying to do it myself would outweigh the cost of getting it built.

I can try the local college, see if someone will knock one together for me.

The Ebay one is OK, but I would prefer something with a greater output and a standard female USB, rather than a small male USB. It would give me more flexibility over device choices.

Whilst a switch for lights is not important now (I'm cycling in Norway in the summer) it might be advantageous in the future.

Fifer

uk-tyler wrote: »

The circuit looks simple enough, but what do I know? I'm electronically illiterate:rotfl:.

www. (dot) arenddeboer (dot) com/bike-mounted-usb-charger/

I'm happy to build a box to house it in and pay for the services of someone to build it for me. However I'd like an expert opinion of whether the circuit is good enough for my needs.

Ideally I'm looking for an output of 5V 500mA at the USB from a 6V 3W input. A switch to allow me to use it to power lights when not using the USB would be a bonus.

That circuit will work fine - it's just a simple full-wave rectifier with smoothing (which converts your AC to DC) feeding a voltage regulator (which stabilises the fluctuating output from the generator), but you possibly won't get 500mA from it. The source (6V @ 3W) will only provide 500mA maximum and there will be losses in the circuitry which will reduce that theoretical maximum. (Although 5V at 500mA is only 2.5W, so it depends what the losses in the regulator circuit are).

uk-tyler

Fifer wrote: »

That circuit will work fine - it's just a simple full-wave rectifier with smoothing (which converts your AC to DC) feeding a voltage regulator (which stabilises the fluctuating output from the generator), but you possibly won't get 500mA from it. The source (6V @ 3W) will only provide 500mA maximum and there will be losses in the circuitry which will reduce that theoretical maximum. (Although 5V at 500mA is only 2.5W, so it depends what the losses in the regulator circuit are).

That's fine, if I can't get any more it will have to do. I suspect it will be good enough for the phone/tracker, which is the important item. The MP3 player I can run from standard batteries.

stevemcol

Awarded to Killer Watt & Espresso for an entertaining cat fight.

KillerWatt

stevemcol wrote: »

Awarded to Killer Watt & Espresso for an entertaining cat fight.

:T

Unfortunately for expresso, he/she was trying to use Wiki against C&G 224 which is akin to attending a gunfight with a knife :rotfl:

bat999

KillerWatt wrote: »

If it produces AC then it is not a dynamo.

You didn't learn that as part of your City and Guilds did you?