Search found 151 matches

by andrew.box
Aug 04 2019 4:22pm
Forum: Motor Technology
Topic: spec'ing out motor for DIY high quality desk fan?
Replies: 5
Views: 231

spec'ing out motor for DIY high quality desk fan?

I'm tired of wasting money on small fans that fail in one way or another after maybe a year or two. I'd like to try and build a desk fan using a high grade automation or servo motor, possibly variable speed DC drive but whatever allows good speed control. Anyone want to help me design the project, s...
by andrew.box
May 22 2019 10:31pm
Forum: Battery Technology
Topic: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!
Replies: 21
Views: 621

Re: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!

fechter wrote:
May 22 2019 9:39pm
andrew.box wrote:
May 22 2019 5:23pm
On the low voltage side, or even to switch the mains?
I'm thinking to switch the mains. The big AC ones can handle the inrush and they aren't super expensive.
Thanks, I'll look into it. Good option to have even if I just switch at the 12v for this project.
by andrew.box
May 22 2019 5:23pm
Forum: Battery Technology
Topic: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!
Replies: 21
Views: 621

Re: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!

fechter wrote:
May 22 2019 2:20pm
A SSR would work well for that application. The inrush of the capacitors charging draws enough current to weld the contacts.
On the low voltage side, or even to switch the mains?
by andrew.box
May 21 2019 10:22pm
Forum: Battery Technology
Topic: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!
Replies: 21
Views: 621

Re: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!

So even with the 2 ohm thermistor you think it would draw more than 10A or so? you'd have to calculate it based on the voltage you're running it on. if it's 115vac, then 115v / 2ohm = 57.5a. you'd also have ot look at the ntc / ptc 's specs to see how long it takes to heat up and become lower resis...
by andrew.box
May 21 2019 9:57pm
Forum: Battery Technology
Topic: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!
Replies: 21
Views: 621

Re: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!

if it's this one https://www.mouser.com/ProductDetail/MEAN-WELL/S-250-12?qs=A0aqJZyP9eUB6nG3oMOuGg%3D%3D then the spec sheet linked there says it's a 45 inrush current at 250vac, which means up to twice that for 115vac. so you have to use a relay capable of at least 90a or it will arc while closing...
by andrew.box
May 21 2019 9:47pm
Forum: Battery Technology
Topic: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!
Replies: 21
Views: 621

Re: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!

Not sure if it’s arcing. I don’t hear anything. This one is enclosed though inside a whole temp controller unit. I put an clamp style meter on it when I first built it and it was showing 5A on the DC side. I think there’s inrush because my workshop lights dim ever so slightly when the relay clicks c...
by andrew.box
May 21 2019 9:13pm
Forum: Battery Technology
Topic: controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!
Replies: 21
Views: 621

controlling meanwell with relay on 120VAC side - relays keep getting stuck closed!

Hey folks, I'm trying to drive a meanwell 12V 18A PSU, model S-250-12, using a standard type relay like one would use with arduino to switch the 120VAC mains to the power supply on and off. Not an SSR or anything, regular relay that goes 'click'. Well, I've had 3 relays now fail closed with this pro...
by andrew.box
Aug 13 2018 10:30am
Forum: Battery Technology
Topic: Diy ltc 6802-2 BMS?
Replies: 10
Views: 1300

Re: Diy ltc 6802-2 BMS?

FYI - I'm nearly finished building a BMS based on four-forty's 12 cell BMS board that uses the 6802 chip. I'll post a build thread soon, but overall I'm happy with how it turned out. (except that my cheap ebay 48v 1500W inverter failed short this weekend, but that's not the BMS's fault). Here's the ...
by andrew.box
Feb 05 2018 11:04am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 872
Views: 100953

Re: kWeld - "Next level" DIY battery spot welder

Cool, thanks! I'm currently wasting all my money on a Volt module based battery backup portable inverter project, but I may want to pick one of these up eventually. They look like great quality little spot welders and price is reasonable.
by andrew.box
Feb 03 2018 12:10pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 872
Views: 100953

Re: kWeld - "Next level" DIY battery spot welder

Wow, nice project. If you end up selling boards or kits please say so here. I bet we could get a number of people who'd reserve a board and parts. Also try the DIY power wall forums, those folks love spot welders.
by andrew.box
Feb 02 2018 11:04pm
Forum: Battery Technology
Topic: bluetooth BMS?
Replies: 1127
Views: 98070

Re: bluetooth BMS?

Interesting thread, but a bit hard to follow. There appear to be at least 3 different bluetooth capable BMS products being discussed here, and not always a clear reference to which one is being discussed in a given post. Like, which software screenshots go with which BMS? Could it be valuable to th...
by andrew.box
Jan 31 2018 2:28pm
Forum: Battery Technology
Topic: bluetooth BMS?
Replies: 1127
Views: 98070

Re: bluetooth BMS?

Interesting thread, but a bit hard to follow. There appear to be at least 3 different bluetooth capable BMS products being discussed here, and not always a clear reference to which one is being discussed in a given post. Like, which software screenshots go with which BMS? Could it be valuable to the...
by andrew.box
Jan 30 2018 7:41pm
Forum: Battery Technology
Topic: Diy ltc 6802-2 BMS?
Replies: 10
Views: 1300

Re: Diy ltc 6802-2 BMS?

I'm not 100% sure on interfacing with the Bestech units, the last ones I got from them weren't 'smart', but the units I linked appear to support a few things including I2C and serial UART. I think the idea is they have software that will program it through a USB to Serial adapter setup into the UART...
by andrew.box
Jan 29 2018 10:44pm
Forum: Battery Technology
Topic: Diy ltc 6802-2 BMS?
Replies: 10
Views: 1300

Re: Diy ltc 6802-2 BMS?

Awesome. Yeah I know of Peter from the Insight forums. He had a lithium insight back before it was even a commercial option for most cars. That guy knows his stuff. Would be great to see a community driven "open" BMS project become active. There are few things like this around, somewhat surprisingly...
by andrew.box
Jan 29 2018 3:27pm
Forum: E-Vehicles General Discussion
Topic: Looks like Sondors is at it again...(E-car)
Replies: 46
Views: 6393

Re: Looks like Sondors is at it again...(E-car)

This looks cool, do they have a chance at success? I was hoping Elio was more than vaporware, but they disappeared a while ago. Either Elio is a moron/dreamer, or he's a crook, not sure which and maybe a little of both. I gave them $100 for a pre-order fully expecting I might never see it again. I h...
by andrew.box
Jan 29 2018 11:15am
Forum: Battery Technology
Topic: Diy ltc 6802-2 BMS?
Replies: 10
Views: 1300

Re: Diy ltc 6802-2 BMS?

Oh, nice. That does seem to do most or all of what I want. Do you plan to have any boards made up? If so I might be willing to pick up a couple. Or if you have the board design files, I guess could order one or two from a PCB manufacturer. Is it at all cost effective to order low numbers of boards, ...
by andrew.box
Jan 27 2018 11:53am
Forum: Battery Technology
Topic: Diy ltc 6802-2 BMS?
Replies: 10
Views: 1300

Diy ltc 6802-2 BMS?

Hey folks, does anyone here have experience putting together something like this and setting custom voltages for cell cutoffs and balancing initiation and using higher current off chip balancing? https://sourcelion.wordpress.com/2014/07/20/battery-management-system-ltc6802-arduino/ Eg any pcbs built...
by andrew.box
Oct 29 2014 7:33pm
Forum: General Discussion
Topic: Elio..... The new Aptera???
Replies: 24
Views: 3868

Re: Elio..... The new Aptera???

Ya, sort of sounds promising and the vehicle looks really good in terms of specs and in my opinion aethetics too. I'd consider getting a reservation, but have mixed feelings about having to pay to reserve something that may very well never exist. But I guess it's really just the crowd funding model ...
by andrew.box
Oct 27 2014 3:03pm
Forum: General Discussion
Topic: Elio..... The new Aptera???
Replies: 24
Views: 3868

Re: Elio..... The new Aptera???

Anyone know if this Elio outfit is going anywhere or actually any closer to building a production vehicle? It seems like this thing hits the sweet spot in terms of price/performance/fuel economy but perhaps too good to be true.
by andrew.box
Jul 21 2014 3:07pm
Forum: E-Bike General Discussion
Topic: shipping tadpole trike
Replies: 2
Views: 369

Re: shipping tadpole trike

Update - just discovered you can ship stuff through Greyhound, the buyer of the bike got a quote from them for $115.00 to ship a box of that size and weight. May be a good option for anyone needing to ship a trike or other bulky things. I think that's what we're going to do, I just need to see if th...
by andrew.box
Jul 21 2014 2:05pm
Forum: E-Bike General Discussion
Topic: shipping tadpole trike
Replies: 2
Views: 369

shipping tadpole trike

Had an offer on my KMX on ebay that's in a range I"ll accept but the potential buyer is in Portland. With wheels and the front boom detached, the bike would go in a box 58 x 32 x 18 and weights 73 lbs. UPS wants $450 + $160 to make a custom box to ship it to Porland zip code. That's std ground. That...
by andrew.box
May 11 2014 9:14am
Forum: E-Bike Build Threads / Photos & Video
Topic: KMX X-class commuter build
Replies: 7
Views: 1244

Re: KMX X-class commuter build

That's first class, nice work!
by andrew.box
Oct 08 2013 8:10am
Forum: Battery Technology
Topic: eBike Master Switch Design
Replies: 331
Views: 32424

Re: eBike Master Switch Design

This is a great idea, I just cooked my master power switch this weekend. Forgot to pre-charge one too many times and it welded itself closed. It was a 30A rated heavy duty toggle switch and I'm running a 25A controller, but inrush current vastly exceeds 30A, obviously, and it just couldn't take it. ...
by andrew.box
Oct 02 2013 8:27pm
Forum: Battery Technology
Topic: slow balancing with Bestech BMS
Replies: 21
Views: 2374

Re: slow balancing with Bestech BMS

That's certainly simpler. I'll try it, thanks!