|Dave Rose||08/12/2017 15:25:05|
|64 forum posts|
I have a field charger that I would now also like to use at home . Can someone who knows about these thing please point me to a "transformer"? Or whatever that I can buy so that I can charge batteries at home. I have a transformer lead which I thought I could make a connection for, but I was told the output amperage was too low?
|Denis Watkins||08/12/2017 15:31:42|
|3799 forum posts|
Shop around, as you can go much higher wattage rating
This 100w is the smallest, but you don't state lipos or charger type
|517 forum posts|
At the risk of being barred for suggesting you look at a different forum you could look here
I use one of these, it cost about £18 and can power several chargers at once if require.
1900 forum posts
It's not worth messing about with it as you would need to alter too much internally . Diodes resistors capacitors etc. Keep your field charger as is and buy a variable multi point mains powered PSU .
Look on the Component Shop site. In fact give them a call for their advice.
|262 forum posts|
Some work required and IIRC will put out up to 50 amps at a regulated 12v? - but worth the effort.
Overkill but powers my 1m hot wire cutter through a brushed esc and servo tester.
|ken anderson.||08/12/2017 16:48:47|
8424 forum posts
hello dave-i bought a transformer from Maplins..
ken Anderson..ne..1.... maplins dept.
|Eagle 899||08/12/2017 17:01:37|
175 forum posts
Server power supply with conversion instructions (credit to MattyB for this link):-
A chap also sells them already converted and advertises regularly in the BMFA Classifieds.
|john stones 1||08/12/2017 17:03:50|
10487 forum posts
I use one of these, very quiet n cheap. Plenty info on converting them.
|Brian Spearing||08/12/2017 17:09:27|
|46 forum posts|
As well as the converted server supply I've been using a Junsi P350 for several years - Junsi make chargers too so you know it's suitable. Not cheap but well made.
Experience* suggests it's important to get a smooth voltage input to your charger, otherwise the all-important cutoff point could be missed.
* If using an ATX PC power supply be sure to check that.
Edited By Brian Spearing on 08/12/2017 17:14:41
1900 forum posts
Or use a battery charger for a supply A good one
|Brian Spearing||08/12/2017 17:16:56|
|46 forum posts|
If you use a car charger remember that car batteries don't care about voltage ripple.
|Geoff Sleath||08/12/2017 18:26:25|
3297 forum posts
That's the one to use, Brian. Cheap and very powerful. I've had one for several years on the recommendation of a poster there (we know who )
609 forum posts
two ways of doing this convert a psu which I have done very good cheep and reliable with the post for the server psu conversion a good way or buy from that chap that advertises or use a 12v car or leasure battery and charge as needed via a standard car bat charger , both the best solutions giving clean linear voltage
|David Ovenden||09/12/2017 05:41:35|
331 forum posts
I too can heartily recommend the HP server power supply conversion as suggested by FlyingBrian. They are so good I have 2. One for each end of the workshop!
|Dave Bran||09/12/2017 06:22:54|
1898 forum posts
I have a number of PSUs used from time to time to feed chargers, some ex-computer, some industrial fully adjustable stabilised lab/bench, but the bank of NIMH chargers (10 of!) I use for the school club are powered by these little devices, three of them. very small, very quiet.
I used to suggest these, HOWEVER, I do not think they are available now AND anyway the price was only £12 each retail when I bought!!
A point with regard using car battery chargers as PSU. They are not! There are also so many types with and without regulation/boost/auto trickle that a blanket "use this" is IMO imprudent.
While I rarely field charge these days, I have a number of very large capacity 4S/6S LiPo which subject to charger input do what I need. They also drive my engine starters. A "Sakura" car engine starter is always in the car anyway and despite being tiny I once used it to start a 7.6 litre 6 cylinder petrol! No more stone age heavy lead acids!
|Chris Channon||09/12/2017 07:31:23|
|539 forum posts||A lot easier to just buy a 12v power supply from a model shop / internet.|
|Martin Harris||09/12/2017 10:22:37|
8728 forum posts
Certainly easier but many of the "hobby" PSUs are built to a price and may not have the reliability or performance of a converted server PSU. If you have the capability to follow the conversion instructions, they are the best value IMHO.
Running directly from a battery charger risks damage to the charger through "dirty" outputs and simpler ones being unregulated and I would caution against the practice. You might get away with it if you have a suitable car battery float charging across the output but there are much better options.
|Steve Hargreaves - Moderator||09/12/2017 12:07:33|
6716 forum posts
Xbox power supplies also do a good job after a little bit of modification.... see here
|Mike T||09/12/2017 14:24:16|
|410 forum posts|
The HP server PS can still be got for under £20 on ebay. The conversion is really easy - just jumper a few pins and away you go. I did the 'full' conversion with mine with fan speed reduction, voltage trim pot and removing all the extraneous metalwork. Outputs are 4mm binding posts - which were cannibalised from a failed 'model shop' PS...
A more complicated, but more flexible alternative is an ATX PS (desktop computer type PS). Also plenty for under £20 and capable of providing multiple outputs at 5, 12, 17 and 24v. Lots of "how to's" on the 'net.
A couple of pics to sum up:
1. HP Server PS:
2. ATX PS:
Edited By Mike T on 09/12/2017 14:30:34
|Geoff Sleath||09/12/2017 15:05:18|
3297 forum posts
Not quite clear about your diagram, Mike.
On mine, I've linked the 3 pins diagonally from PSON and it's been working fine for several years. You show the fan speed control as linked to those 3 as well but then suggested grounding it. Is that after disconnecting it from the other 3 or are all 4 pins grounded? I've left that fan speed pin open circuit.
The only thing I don't like about mine is the fan noise and it would be an improvement to either eliminate or, at least, reduce it.
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