Electronics questio...
 

MegaSack DRAW - This year's winner is user - rgwb
We will be in touch

[Closed] Electronics question (bike kit related)

6 Posts
3 Users
0 Reactions
75 Views
Posts: 9393
Free Member
Topic starter
 

I think there's a fair few electronics experts on here.. and I'm not one of them.

I have some components ready to build a dynamo battery charger. Some of the parts (5v regulator and the USB female port for eg, also a on/off/on switch) have contact 'legs' or wires but I'm not sure how to figure out which is which for polarity.
I have an Evo meter so if I connect an AA to a bit of wire what's the easy way to check the fitting or routing? Do I even need a cell for output? I think there's an easy answer to this but I'm not sure and don't want to risk blowing small parts.


 
Posted : 15/08/2014 6:58 am
Posts: 4693
Full Member
 

Just type the number of the part into google and find the data sheet.


 
Posted : 15/08/2014 7:02 am
Posts: 9393
Free Member
Topic starter
 

That's useful, thanks. Didn't know parts had that info available.

http://www.ic-on-line.cn/view_online.php?id=1128903&file=0065\pth08000w_506136.pdf

GRD - how's that connection made, an isolated connection to base board w/o link to other parts?
Need a couple of capacitors to go with it.


 
Posted : 15/08/2014 7:17 am
Posts: 91098
Free Member
 

Be careful with the regulator. I made one to power my garmin from my light battery, and turns out the basic kind simply dump all the excess power as heat which not only wasted a lot of power but made it so hot it'd burn me if I touched it.


 
Posted : 15/08/2014 7:36 am
Posts: 4693
Full Member
 

Yes, if you can bolt the regulator (there's normally a hole on the base) to some metal.


 
Posted : 15/08/2014 7:44 am
Posts: 9393
Free Member
Topic starter
 

Got 2 types of regulator, the one linked to is a more complex one that needs capacitors and a resistor and re-generates the input into the right output (so less heat as far as I understand), and a basic one that will need a heat-sink. Complex one looks to be a lot more efficient.


 
Posted : 15/08/2014 7:50 am
Posts: 9393
Free Member
Topic starter
 

"resistor 1% .05W 348Ohm" = 3R5, or 3R4.8 if it exists?

Not an easy one to find. Odd spec?
Edit, will just line a couple up.


 
Posted : 15/08/2014 8:01 am