Announcement

**stj** · 06-05-2018, 08:37 AM

Re: Friwo EC205 battery charger at 60Hz?

u.k. does not use 2pin, other than old shavers - with fat pins.
i know the plug your talking about, it's used in places like italy a lot and will fit in a schuko socket - badly.

does it contain a linear transformer, or is it a switching psu?

**eccerr0r** · 06-05-2018, 09:13 AM

Re: Friwo EC205 battery charger at 60Hz?

Strange, then what is used in the UK? This device has a two prong and a squashed hexagon plastic piece that the prongs extend out of... It's weird to me that it has both German and English written on it, but omitted the countries in between... I'll need to find or get some pictures up I suppose.

Not sure what it has since I haven't opened it yet; it feels dense enough it could have a linear (which should be fine at 60Hz) but it's not THAT dense. Since it appears it can charge AA cells individually I'm not sure what it has. I haven't opened it because it uses tri-wing security screws and I can't find my security bit set.

Can't tell how old this thing is either but I would guess no older than around 20 years, might be younger. I don't see "Made in China" anywhere which is odd...

**stj** · 06-05-2018, 09:24 AM

Re: Friwo EC205 battery charger at 60Hz?

british "shaver" plugs have fatter pins.
pisses people off when they try to use a "travel adapter" and it wont fit - they have to buy a "shaver adapter"

a linear transformer may run hotter at the wrong frequency, but a switching psu wont care because it just rectifies it to dc.
infact it may run at 110v even if it's not marked on it.

**stj** · 06-05-2018, 09:25 AM

Re: Friwo EC205 battery charger at 60Hz?

btw, as far as age - they are on sale on amazon - i searched the part number.

**eccerr0r** · 06-05-2018, 10:02 AM

Re: Friwo EC205 battery charger at 60Hz?

Does not appear to be a current model as it doesn't show up on Friwo.de website...
Since Friwo is still in business, it shouldn't be that crappy of a device?

Strange though it is designed for 50Hz, at a higher 60Hz frequency, a linear PSU's transformer's core shouldn't saturate. I would imagine it too is a laminated steel core, but can't think of why there would significantly be more eddy current losses at 60Hz.

Haven't tried it running at 120VAC yet...

**stj** · 06-05-2018, 11:55 AM

Re: Friwo EC205 battery charger at 60Hz?

i suspect it's a switcher in it.

**eccerr0r** · 06-05-2018, 08:55 PM

Re: Friwo EC205 battery charger at 60Hz?

RUBBISH! This thing is rubbish!
It's linear, not switching, tiny little iron core transformer in it!
Gar-Bage! Nothing worth salvaging in this, just those tri-wing self tapping screws if even...

I wonder what to do with this thing, likely belongs in file 13...

**stj** · 06-06-2018, 05:29 AM

Re: Friwo EC205 battery charger at 60Hz?

well if you need a charger, and dont need 9v.
i recommend a Liitokala Lii500-Engineer
https://www.banggood.com/LiitoKala-L...-p-999106.html

**eccerr0r** · 06-06-2018, 07:18 AM

Re: Friwo EC205 battery charger at 60Hz?

Nah, no big need for it, it was just something I had that I could test the step up autotransformer without blowing

Probably could also try the autoranging wall warts too, but the charger was obviously designed for 220V. I could also plug the other autotransformer into the autotransformer and see if regular devices work...

... or something can completely blow up at 480V

Pictures added for your viewing pleasure or pain, depending on how it's viewed

Attached Files

**stj** · 06-06-2018, 12:23 PM

Re: Friwo EC205 battery charger at 60Hz?

i like the last option!
maybe re-charge some old batteries at 480v!!!
it should handle it, the diodes and resistors wont go over-voltage!!

battery BOOM-time!

**eccerr0r** · 06-06-2018, 03:56 PM

Re: Friwo EC205 battery charger at 60Hz?

I do wonder if these autotransformers can hold 480V without arcover or not.
Seems like it's very possible to select the wrong voltage, is the expectation to destroy fuses, the autotransformer, or the downstream device?

**stj** · 06-06-2018, 07:27 PM

Re: Friwo EC205 battery charger at 60Hz?

well, the transformer is just a divider/multplier, so as long as the laq is thick enough to prevent the windings arcing, they wont care.

that charger is outputting about 1.5v so if you double it your outputting 3v and that wont harm the diodes or resistors.

so i suspect other than a bit more heat, your just going to cook some batteries - got any old alkalines?

**eccerr0r** · 06-06-2018, 07:36 PM

Re: Friwo EC205 battery charger at 60Hz?

Right, I was wondering how sturdy the (autotransformer) voltage converters were, if you accidentally set the voltage input wrong and plugged it in. I would suspect people in the 220V areas would have more experience setting the autotransformer input to 120V and plugging it in, theoretically resulting in that 440-480V

Alas for us puny 120V'ers, we only can test the lower winding for sturdiness (drawing more current out of the secondary output just causes more strain on the input winding/core...)

**stj** · 06-07-2018, 04:18 AM

Re: Friwo EC205 battery charger at 60Hz?

autotransformers are rare in europe,
very few people have japanese (100v) or u.s. imported electronics.

our industial powertools are 110v for outdoor safety,
but they run through a fully potted isolation transformer with a 55-0-55 output with the centertap bonded to earth.
so the wost that can happen is you get a 55v shock.

**eccerr0r** · 06-07-2018, 06:42 AM

Re: Friwo EC205 battery charger at 60Hz?

I suspect there are laws that force the manufacturers to prevent people from connecting those isolation transformers backwards?

**stj** · 06-07-2018, 08:28 AM

Re: Friwo EC205 battery charger at 60Hz?

no, we have freedom to kill ourselves.

just as long as it's intentional and cant happen by accident.
which is unlikely!

**eccerr0r** · 06-07-2018, 08:31 AM

Re: Friwo EC205 battery charger at 60Hz?

The autotransformers that I have indeed can be set in the wrong direction... so why these and not that... (plus the fact autotransformers are not isolated!!!)

**budm** · 06-07-2018, 10:03 AM

Re: Friwo EC205 battery charger at 60Hz?

Auttransformer can be used as buck or boost I.E. like the way they used in the UPS that has AVR and there is no need for isolation since the Neutral in goes directly to the Neutral out, it has its use and purpose. VARIAC is basically variable AUTOtransformer

**eccerr0r** · 06-07-2018, 11:42 AM

Re: Friwo EC205 battery charger at 60Hz?

Right, alas, I was wondering if you had an autotransformer in a 220V area and you set the input to 120V with 220V going in, what's the chances you get
1. 440V out
2. Molten piece of copper, steel, and fire mess when the insulation arcs over...

Announcement

Friwo EC205 battery charger at 60Hz?

Friwo EC205 battery charger at 60Hz?

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment