Search found 21 matches

by EDS
Apr 26 2017 6:34pm
Forum: Battery Technology
Topic: Current Mod for Meanwell HRP-450-24
Replies: 11
Views: 1306

Re: Current Mod for Meanwell HRP-450-24

I think I have a good idea how to figure it out. I originally thought the overcurrent circuit would be on the main board, near the output terminals, but there aren't many components there at all. There's a thru-hole resistor labeled L151 (which I don't understand since that looks like an inductor de...
by EDS
Apr 26 2017 1:36pm
Forum: Battery Technology
Topic: Current Mod for Meanwell HRP-450-24
Replies: 11
Views: 1306

Re: Current Mod for Meanwell HRP-450-24

For pot size, I'm not an expert, but this is what I think would work. Try to read the text (if SMT) or bands (if thru hole) to find the value of the resistor you are planning to put the pot in parallel with. Measuring it in-situ may not be accurate, b/c it may be connected to other things in paralle...
by EDS
Apr 25 2017 7:38am
Forum: Battery Technology
Topic: Current Mod for Meanwell HRP-450-24
Replies: 11
Views: 1306

Re: Current Mod for Meanwell HRP-450-24

Thanks for the information. I'll search for DrAngle. I had looked for Fetcher's limiter, but the boards are long gone. Could breadboard it, but it makes so much more sense to simply add one pot to the existing circuit. Assuming the relevant circuit is near the output terminals, there aren't many com...
by EDS
Apr 16 2017 2:55pm
Forum: Battery Technology
Topic: Current Mod for Meanwell HRP-450-24
Replies: 11
Views: 1306

Current Mod for Meanwell HRP-450-24

I have several of these power supplies in my junk pile, so I would like to do the "R33" type mod to drop the current, as described here: http://www.recumbents.com/WISIL/e-bent/meanwell/default.htm I've spent a while looking at similar conversions, but have not found info for this particular model (v...
by EDS
Apr 16 2017 9:36am
Forum: Battery Technology
Topic: Hybrid lipo/18650 pack, different capacity ?
Replies: 32
Views: 3698

Re: Hybrid lipo/18650 pack, different capacity ?

I take back my statement about the relative IR not being important. Sorry if this is redundant to something above - I haven't reviewed all the other posts closely, but I skimmed Craig's last post enough to notice that I was being chastised, so I thought about it a little more. Paralleling packs toge...
by EDS
Apr 08 2017 11:21pm
Forum: Battery Technology
Topic: Hybrid lipo/18650 pack, different capacity ?
Replies: 32
Views: 3698

Re: Hybrid lipo/18650 pack, different capacity ?

You can parallel different capacity packs. I don't think the relative IR is important either. They always stay perfectly balanced to each other. They have to. Their terminals are on the same nodes in the circuit. RC plane guys used to do it (probably don't bother any more since lipos are cheap & hig...
by EDS
Apr 08 2017 10:28pm
Forum: Battery Technology
Topic: Max safe input voltage for Turnigy chargers
Replies: 5
Views: 1055

Re: Max safe input voltage for Turnigy chargers

I hooked the Reaktor to the lab supply. 18.0V works fine. 18.1V gives the error message. I didn't test the Accucell since I didn't have a suitable plug handy, but based on Hillhater's post above, ironically the 50W Accucell will take higher voltage, but the 250W Reaktor will not. Will see if I can t...
by EDS
Apr 05 2017 10:44pm
Forum: E-Bike General Discussion
Topic: e-bikes on Colorado Rec Paths?
Replies: 7
Views: 688

Re: e-bikes on Colorado Rec Paths?

Not sure about those specific places, but it could be complicated. Boulder has a great network of paths. I saw a map once that showed that some of them allowed ebikes and some did not. The ebike-allowed paths seemed to be random and were not connected. You couldn't really get around using them. I do...
by EDS
Apr 05 2017 9:26am
Forum: Battery Technology
Topic: Max safe input voltage for Turnigy chargers
Replies: 5
Views: 1055

Re: Max safe input voltage for Turnigy chargers

Thanks Hillhater, that sounds perfect. I was rummaging through my junk and realized I've got about a dozen Dell supplies so I'll just reterminate one of them. Also noticed that the Reaktor will only work at less than one third power if powered through the jack, so I need to use the cable input anywa...
by EDS
Mar 30 2017 3:47pm
Forum: Battery Technology
Topic: Max safe input voltage for Turnigy chargers
Replies: 5
Views: 1055

Re: Max safe input voltage for Turnigy chargers

Thanks Kinninviekid. Sounds like a little over might not work, but probably won't break it. I'll hook it up to my lab supply and figure out if it gives the error message around 19.5V.
by EDS
Mar 30 2017 8:07am
Forum: Battery Technology
Topic: Max safe input voltage for Turnigy chargers
Replies: 5
Views: 1055

Max safe input voltage for Turnigy chargers

I have a couple of Turnigy chargers (Accucell 6 & Reaktor). The manuals state the max input voltage is 18V. I have spare Dell laptop power supplies which indicate 19.5V, so they may be slightly higher, at least open circuit. Has anyone used higher voltage with these chargers, or do you have insight ...
by EDS
Dec 16 2016 8:24pm
Forum: E-Bike Non-hub Motor Drives
Topic: Kepler Friction drive comes of age.
Replies: 401
Views: 77556

Re: Kepler Friction drive comes of age.

Looks good. Love the simplicity. I've been itching to make one of these ever since I saw yours & Adrian's original posts years ago. I finally decided to start my own build, but if I can buy your kit I may do that instead to save time. We recently bought a 44 year old house that needs lots of work, a...
by EDS
Oct 26 2011 10:42pm
Forum: Motor Technology
Topic: Using Multiple Magnets to make a single pole.
Replies: 10
Views: 1640

Halbach array

If you're going to use multiple magnets together, check out the Halbach array. If you arrange adjacent magnets with the poles alternating in a particular pattern it effectively makes 2x the flux on one side, and no flux on the other. You'd want to use magnets with a square cross section though since...
by EDS
Jun 20 2011 7:56pm
Forum: E-Bike Non-hub Motor Drives
Topic: Water-Cooled, 63mm, 8kW
Replies: 12
Views: 2049

Water-Cooled, 63mm, 8kW

I stumbled across this while searching for a centrifugal fan for my Turnigy 6364-280. http://littlescreamers.com/id57.html The kV is high (650), but it looks like a low-volume outfit that might do a custom wind or maybe let you wind it yourself. $105 shipped from USA sounds pretty good. I'd still ra...
by EDS
Apr 06 2011 12:45pm
Forum: Motor Technology
Topic: advice on motor rewire
Replies: 2
Views: 672

Re: advice on motor rewire

Thud, thanks for the info. I have those tools, so I can do that. I probably will end up rewinding it later. I'm dragging the whole project out into many steps, so I can learn as much as possible along the way. Do you remember how well the 16g worked out? HK states it is 16turns. Does a single strand...
by EDS
Apr 05 2011 1:24pm
Forum: Motor Technology
Topic: advice on motor rewire
Replies: 2
Views: 672

advice on motor rewire

I have a Turnigy 6364-280 that I'm in the process of switching from delta to wye. I finally got it apart using screw extractors - all the flatheads were superglued (not threadlocked) in place. The strands are not in nice pairs like in Jeremy's pictures. It's like an M.C. Escher painting in there; ev...
by EDS
Apr 01 2011 9:50am
Forum: General Discussion
Topic: Cheap DVM's on e-bay
Replies: 21
Views: 1715

Short circuit safety feature

There's a meter we have at work that will beep at you if you turn the dial to voltage with a lead plugged in to the current jack. It's the same sound as when you're testing continuity. Great feature. The brand is BK Test Bench. I haven't had low current range on my meter for years - since I tried to...
by EDS
Mar 23 2011 9:34pm
Forum: General Discussion
Topic: Thank You Endless Sphere
Replies: 3
Views: 628

Thank You Endless Sphere

This week I started commuting to work on an electric vehicle I made (just a board - maybe something bigger later). This site was the best source of information.  Some forums seem to have more bickering & opinions than useful discussion. This site has people who actually do things & post results.  ...
by EDS
Mar 08 2011 10:00pm
Forum: Motor Technology
Topic: Flux Density Map for Turnigy 6364-280
Replies: 1
Views: 835

Flux Density Map for Turnigy 6364-280

Hopefully this will help someone spec & locate hall effect sensors. I decided to do this after seeing where bigmoose did something similar for the 80mm motor. I'm not sure I understand what the +10º & +20º plots he made are for. If someone wants something like that please let me know & I can proba...
by EDS
Jan 12 2011 11:49pm
Forum: Motor Technology
Topic: Updated Cap choices for high power motor controllers Updated
Replies: 92
Views: 33565

More film cap info

liveforphysics, I'm not sure I understand what you're describing. Maybe it's a different type of cap. I only worked with film. For wound film caps, there's no question that a low aspect ratio shape (hockey puck) results in lower ESR than pencil-shaped. All of the parts I worked on were custom, costi...
by EDS
Jan 11 2011 8:14pm
Forum: Motor Technology
Topic: Updated Cap choices for high power motor controllers Updated
Replies: 92
Views: 33565

Re: Updated Cap choices for high power motor controllers Upd

I wish this would have come up a few years ago. I used to be an engineer at a company that made film capacitors. I could have made something better than any of the catalogue caps mentioned (lower ESR & ESL at least). Some of my projects went on the motor controller units of aircraft & probably serve...